From 9b2416233a601c9925f6415a0f9074ea7dac04f4 Mon Sep 17 00:00:00 2001 From: aevesdocker Date: Wed, 1 May 2024 10:54:12 +0100 Subject: [PATCH 1/2] Add legacy reference files Signed-off-by: aevesdocker --- docs/Compose file reference/version-2.md | 1967 ++++++++++++++++++++++ docs/Compose file reference/version-3.md | 0 2 files changed, 1967 insertions(+) create mode 100644 docs/Compose file reference/version-2.md create mode 100644 docs/Compose file reference/version-3.md diff --git a/docs/Compose file reference/version-2.md b/docs/Compose file reference/version-2.md new file mode 100644 index 0000000000..7865755317 --- /dev/null +++ b/docs/Compose file reference/version-2.md @@ -0,0 +1,1967 @@ +These topics describe version 2 of the Compose file format. + +## Compose and Docker compatibility matrix + +There are several versions of the Compose file format – 1, 2, 2.x, and 3.x. The +table below is a quick look. For full details on what each version includes and +how to upgrade, see **[About versions and upgrading](compose-versioning.md)**. + +{{< include "content/compose-matrix.md" >}} + +## Service configuration reference + +The Compose file is a [YAML](https://yaml.org) file defining +[services](#service-configuration-reference), +[networks](#network-configuration-reference) and +[volumes](#volume-configuration-reference). +The default path for a Compose file is `./docker-compose.yml`. + +> **Tip**: You can use either a `.yml` or `.yaml` extension for this file. +> They both work. + +A service definition contains configuration that is applied to each +container started for that service, much like passing command-line parameters to +`docker run`. Likewise, network and volume definitions are analogous to +`docker network create` and `docker volume create`. + +As with `docker run`, options specified in the Dockerfile, such as `CMD`, +`EXPOSE`, `VOLUME`, `ENV`, are respected by default - you don't need to +specify them again in `docker-compose.yml`. + +You can use environment variables in configuration values with a Bash-like +`${VARIABLE}` syntax - see [variable substitution](#variable-substitution) for +full details. + +This section contains a list of all configuration options supported by a service +definition in version 2. + +### blkio_config + +A set of configuration options to set block IO limits for this service. + + version: "{{% param "compose_file_v2" %}}" + services: + foo: + image: busybox + blkio_config: + weight: 300 + weight_device: + - path: /dev/sda + weight: 400 + device_read_bps: + - path: /dev/sdb + rate: '12mb' + device_read_iops: + - path: /dev/sdb + rate: 120 + device_write_bps: + - path: /dev/sdb + rate: '1024k' + device_write_iops: + - path: /dev/sdb + rate: 30 + +#### device_read_bps, device_write_bps + +Set a limit in bytes per second for read / write operations on a given device. +Each item in the list must have two keys: + +* `path`, defining the symbolic path to the affected device +* `rate`, either as an integer value representing the number of bytes or as + a string expressing a [byte value](#specifying-byte-values). + +#### device_read_iops, device_write_iops + +Set a limit in operations per second for read / write operations on a given +device. Each item in the list must have two keys: + +* `path`, defining the symbolic path to the affected device +* `rate`, as an integer value representing the permitted number of operations + per second. + +#### weight + +Modify the proportion of bandwidth allocated to this service relative to other +services. Takes an integer value between 10 and 1000, with 500 being the +default. + +#### weight_device + +Fine-tune bandwidth allocation by device. Each item in the list must have +two keys: + +* `path`, defining the symbolic path to the affected device +* `weight`, an integer value between 10 and 1000 + +### build + +Configuration options that are applied at build time. + +`build` can be specified either as a string containing a path to the build +context: + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + webapp: + build: ./dir +``` + +Or, as an object with the path specified under [context](#context) and +optionally [Dockerfile](#dockerfile) and [args](#args): + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + webapp: + build: + context: ./dir + dockerfile: Dockerfile-alternate + args: + buildno: 1 +``` + +If you specify `image` as well as `build`, then Compose names the built image +with the `webapp` and optional `tag` specified in `image`: + +```yaml +build: ./dir +image: webapp:tag +``` + +This results in an image named `webapp` and tagged `tag`, built from `./dir`. + +#### context + +> Added in [version 2.0](compose-versioning.md#version-2) file format. + +Either a path to a directory containing a Dockerfile, or a url to a git repository. + +When the value supplied is a relative path, it is interpreted as relative to the +location of the Compose file. This directory is also the build context that is +sent to the Docker daemon. + +Compose builds and tags it with a generated name, and uses that image +thereafter. + +```yaml +build: + context: ./dir +``` + +#### dockerfile + +Alternate Dockerfile. + +Compose uses an alternate file to build with. A build path must also be +specified. + +```yaml +build: + context: . + dockerfile: Dockerfile-alternate +``` + +#### args + +> Added in [version 2.0](compose-versioning.md#version-2) file format. + +Add build arguments, which are environment variables accessible only during the +build process. + +First, specify the arguments in your Dockerfile: + +```dockerfile +# syntax=docker/dockerfile:1 + +ARG buildno +ARG gitcommithash + +RUN echo "Build number: $buildno" +RUN echo "Based on commit: $gitcommithash" +``` + +Then specify the arguments under the `build` key. You can pass a mapping +or a list: + +```yaml +build: + context: . + args: + buildno: 1 + gitcommithash: cdc3b19 +``` + +```yaml +build: + context: . + args: + - buildno=1 + - gitcommithash=cdc3b19 +``` + +> Scope of build-args +> +> In your Dockerfile, if you specify `ARG` before the `FROM` instruction, +> `ARG` is not available in the build instructions under `FROM`. +> If you need an argument to be available in both places, also specify it under +> the `FROM` instruction. Refer to the [understand how ARGS and FROM interact](../../reference/dockerfile.md#understand-how-arg-and-from-interact) +> section in the documentation for usage details. + +You can omit the value when specifying a build argument, in which case its value +at build time is the value in the environment where Compose is running. + +```yaml +args: + - buildno + - gitcommithash +``` + +> Tip when using boolean values +> +> YAML boolean values (`"true"`, `"false"`, `"yes"`, `"no"`, `"on"`, +> `"off"`) must be enclosed in quotes, so that the parser interprets them as +> strings. + +#### cache_from + +> Added in [version 2.2](compose-versioning.md#version-22) file format + +A list of images that the engine uses for cache resolution. + +```yaml +build: + context: . + cache_from: + - alpine:latest + - corp/web_app:3.14 +``` + +#### extra_hosts + +Add hostname mappings at build-time. Use the same values as the docker client `--add-host` parameter. + +```yaml +extra_hosts: + - "somehost:162.242.195.82" + - "otherhost:50.31.209.229" +``` + +An entry with the ip address and hostname is created in `/etc/hosts` inside containers for this build, e.g: + +```console +162.242.195.82 somehost +50.31.209.229 otherhost +``` + +#### isolation + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Specify a build’s container isolation technology. On Linux, the only supported value +is `default`. On Windows, acceptable values are `default`, `process` and +`hyperv`. Refer to the +[Docker Engine docs](../../reference/cli/docker/container/run.md#isolation) +for details. + +If unspecified, Compose will use the `isolation` value found in the service's definition +to determine the value to use for builds. + +#### labels + +> Added in [version 2.1](compose-versioning.md#version-21) file format + +Add metadata to the resulting image using [Docker labels](../../config/labels-custom-metadata.md). +You can use either an array or a dictionary. + +It's recommended that you use reverse-DNS notation to prevent your labels from +conflicting with those used by other software. + +```yaml +build: + context: . + labels: + com.example.description: "Accounting webapp" + com.example.department: "Finance" + com.example.label-with-empty-value: "" +``` + +```yaml +build: + context: . + labels: + - "com.example.description=Accounting webapp" + - "com.example.department=Finance" + - "com.example.label-with-empty-value" +``` + +#### network + +> Added in [version 2.2](compose-versioning.md#version-22) file format + +Set the network containers connect to for the `RUN` instructions during +build. + +```yaml +build: + context: . + network: host +``` + +```yaml +build: + context: . + network: custom_network_1 +``` + +Use `none` to disable networking during build: + +```yaml +build: + context: . + network: none +``` + +#### shm_size + +> Added in [version 2.3](compose-versioning.md#version-23) file format + +Set the size of the `/dev/shm` partition for this build's containers. Specify +as an integer value representing the number of bytes or as a string expressing +a [byte value](#specifying-byte-values). + +```yaml +build: + context: . + shm_size: '2gb' +``` + +```yaml +build: + context: . + shm_size: 10000000 +``` + +#### target + +> Added in [version 2.3](compose-versioning.md#version-23) file format + +Build the specified stage as defined inside the `Dockerfile`. See the +[multi-stage build docs](../../build/building/multi-stage.md) for +details. + +```yaml +build: + context: . + target: prod +``` + +### cap_add, cap_drop + +Add or drop container capabilities. +See `man 7 capabilities` for a full list. + +```yaml +cap_add: + - ALL + +cap_drop: + - NET_ADMIN + - SYS_ADMIN +``` + +### cgroup_parent + +Specify an optional parent cgroup for the container. + +```yaml +cgroup_parent: m-executor-abcd +``` + +### command + +Override the default command. + +```yaml +command: bundle exec thin -p 3000 +``` + +The command can also be a list, in a manner similar to +[dockerfile](../../reference/dockerfile.md#cmd): + +```yaml +command: ["bundle", "exec", "thin", "-p", "3000"] +``` + +### container_name + +Specify a custom container name, rather than a generated default name. + +```yaml +container_name: my-web-container +``` + +Because Docker container names must be unique, you cannot scale a service beyond +1 container if you have specified a custom name. Attempting to do so results in +an error. + +### cpu_rt_runtime, cpu_rt_period + +> Added in [version 2.2](compose-versioning.md#version-22) file format + +Configure CPU allocation parameters using the Docker daemon realtime scheduler. + +```yaml +cpu_rt_runtime: '400ms' +cpu_rt_period: '1400us' +``` + +Integer values will use microseconds as units: + +```yaml +cpu_rt_runtime: 95000 +cpu_rt_period: 11000 +``` + +### device_cgroup_rules + +> Added in [version 2.3](compose-versioning.md#version-23) file format. + +Add rules to the cgroup allowed devices list. + +```yaml +device_cgroup_rules: + - 'c 1:3 mr' + - 'a 7:* rmw' +``` + +### devices + +List of device mappings. Uses the same format as the `--device` docker +client create option. + +```yaml +devices: + - "/dev/ttyUSB0:/dev/ttyUSB0" +``` + +### depends_on + +> Added in [version 2.0](compose-versioning.md#version-2) file format. + +Express dependency between services. Service dependencies cause the following +behaviors: + +- `docker-compose up` starts services in dependency order. In the following + example, `db` and `redis` are started before `web`. +- `docker-compose up SERVICE` automatically includes `SERVICE`'s + dependencies. In the example below, `docker-compose up web` also + creates and starts `db` and `redis`. +- `docker-compose stop` stops services in dependency order. In the following + example, `web` is stopped before `db` and `redis`. + +Simple example: + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + web: + build: . + depends_on: + - db + - redis + redis: + image: redis + db: + image: postgres +``` + +> **Note** +> +> `depends_on` does not wait for `db` and `redis` to be "ready" before +> starting `web` - only until they have been started. If you need to wait +> for a service to be ready, see [Controlling startup order](../startup-order.md) +> for more on this problem and strategies for solving it. + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +A healthcheck indicates that you want a dependency to wait +for another container to be "healthy" (as indicated by a successful state from +the healthcheck) before starting. + +Example: + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + web: + build: . + depends_on: + db: + condition: service_healthy + redis: + condition: service_started + redis: + image: redis + db: + image: postgres + healthcheck: + test: "exit 0" +``` + +In the above example, Compose waits for the `redis` service to be started +(legacy behavior) and the `db` service to be healthy before starting `web`. + +See the [healthcheck section](#healthcheck) for complementary +information. + +### dns + +Custom DNS servers. Can be a single value or a list. + +```yaml +dns: 8.8.8.8 +``` + +```yaml +dns: + - 8.8.8.8 + - 9.9.9.9 +``` + +### dns_opt + +List of custom DNS options to be added to the container's `resolv.conf` file. + +```yaml +dns_opt: + - use-vc + - no-tld-query +``` + +### dns_search + +Custom DNS search domains. Can be a single value or a list. + +```yaml +dns_search: example.com +``` + +```yaml +dns_search: + - dc1.example.com + - dc2.example.com +``` + +### entrypoint + +Override the default entrypoint. + +```yaml +entrypoint: /code/entrypoint.sh +``` + +The entrypoint can also be a list, in a manner similar to +[dockerfile](../../reference/dockerfile.md#entrypoint): + +```yaml +entrypoint: ["php", "-d", "memory_limit=-1", "vendor/bin/phpunit"] +``` + +> **Note** +> +> Setting `entrypoint` both overrides any default entrypoint set on the service's +> image with the `ENTRYPOINT` Dockerfile instruction, *and* clears out any default +> command on the image - meaning that if there's a `CMD` instruction in the +> Dockerfile, it is ignored. + +### env_file + +Add environment variables from a file. Can be a single value or a list. + +If you have specified a Compose file with `docker-compose -f FILE`, paths in +`env_file` are relative to the directory that file is in. + +Environment variables declared in the [environment](#environment) section +_override_ these values – this holds true even if those values are +empty or undefined. + +```yaml +env_file: .env +``` + +```yaml +env_file: + - ./common.env + - ./apps/web.env + - /opt/runtime_opts.env +``` + +Compose expects each line in an env file to be in `VAR=VAL` format. Lines +beginning with `#` are treated as comments and are ignored. Blank lines are +also ignored. + +```console +# Set Rails/Rack environment +RACK_ENV=development +``` + +> **Note** +> +> If your service specifies a [build](#build) option, variables defined in +> environment files are _not_ automatically visible during the build. Use +> the [args](#args) sub-option of `build` to define build-time environment +> variables. + +The value of `VAL` is used as is and not modified at all. For example if the +value is surrounded by quotes (as is often the case of shell variables), the +quotes are included in the value passed to Compose. + +Keep in mind that _the order of files in the list is significant in determining +the value assigned to a variable that shows up more than once_. The files in the +list are processed from the top down. For the same variable specified in file +`a.env` and assigned a different value in file `b.env`, if `b.env` is +listed below (after), then the value from `b.env` stands. For example, given the +following declaration in `docker-compose.yml`: + +```yaml +services: + some-service: + env_file: + - a.env + - b.env +``` + +And the following files: + +```console +# a.env +VAR=1 +``` + +and + +```console +# b.env +VAR=hello +``` + +`$VAR` is `hello`. + +### environment + +Add environment variables. You can use either an array or a dictionary. Any +boolean values (true, false, yes, no) need to be enclosed in quotes to ensure +they are not converted to True or False by the YML parser. + +Environment variables with only a key are resolved to their values on the +machine Compose is running on, which can be helpful for secret or host-specific values. + +```yaml +environment: + RACK_ENV: development + SHOW: 'true' + SESSION_SECRET: +``` + +```yaml +environment: + - RACK_ENV=development + - SHOW=true + - SESSION_SECRET +``` + +> **Note** +> +> If your service specifies a [build](#build) option, variables defined in +> `environment` are _not_ automatically visible during the build. Use the +> [args](#args) sub-option of `build` to define build-time environment +> variables. + +### expose + +Expose ports without publishing them to the host machine - they'll only be +accessible to linked services. Only the internal port can be specified. + +```yaml +expose: + - "3000" + - "8000" +``` + +### extends + +Extend another service, in the current file or another, optionally overriding +configuration. + +You can use `extends` on any service together with other configuration keys. +The `extends` value must be a dictionary defined with a required `service` +and an optional `file` key. + +```yaml +extends: + file: common.yml + service: webapp +``` + +The `service` is the name of the service being extended, for example +`web` or `database`. The `file` is the location of a Compose configuration +file defining that service. + +If you omit the `file` Compose looks for the service configuration in the +current file. The `file` value can be an absolute or relative path. If you +specify a relative path, Compose treats it as relative to the location of the +current file. + +You can extend a service that itself extends another. You can extend +indefinitely. Compose does not support circular references and `docker-compose` +returns an error if it encounters one. + +For more on `extends`, see the +[the extends documentation](../multiple-compose-files/extends.md) + +### external_links + +Link to containers started outside this `docker-compose.yml` or even outside of +Compose, especially for containers that provide shared or common services. +`external_links` follow semantics similar to the legacy option `links` when +specifying both the container name and the link alias (`CONTAINER:ALIAS`). + +```yaml +external_links: + - redis_1 + - project_db_1:mysql + - project_db_1:postgresql +``` + +> **Note** +> +> If you're using the [version 2 or above file format](compose-versioning.md#version-2), +> the externally-created containers must be connected to at least one of the same +> networks as the service that is linking to them. [Links](compose-file-v2.md#links) +> are a legacy option. We recommend using [networks](#networks) instead. + +### extra_hosts + +Add hostname mappings. Use the same values as the docker client `--add-host` parameter. + +```yaml +extra_hosts: + - "somehost:162.242.195.82" + - "otherhost:50.31.209.229" +``` + +An entry with the ip address and hostname is created in `/etc/hosts` inside containers for this service, e.g: + +```console +162.242.195.82 somehost +50.31.209.229 otherhost +``` + +### group_add + +Specify additional groups (by name or number) which the user inside the +container should be a member of. Groups must exist in both the container and the +host system to be added. An example of where this is useful is when multiple +containers (running as different users) need to all read or write the same +file on the host system. That file can be owned by a group shared by all the +containers, and specified in `group_add`. See the +[Docker documentation](../../reference/cli/docker/container/run.md#additional-groups) for more +details. + +A full example: + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + myservice: + image: alpine + group_add: + - mail +``` + +Running `id` inside the created container shows that the user belongs to +the `mail` group, which would not have been the case if `group_add` were not +used. + +### healthcheck + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Configure a check that's run to determine whether or not containers for this +service are "healthy". See the docs for the +[HEALTHCHECK Dockerfile instruction](../../reference/dockerfile.md#healthcheck) +for details on how healthchecks work. + +```yaml +healthcheck: + test: ["CMD", "curl", "-f", "http://localhost"] + interval: 1m30s + timeout: 10s + retries: 3 + start_period: 40s +``` + +`interval`, `timeout` and `start_period` are specified as +[durations](#specifying-durations). + +> Added in [version 2.3](compose-versioning.md#version-23) file format. +> +> The `start_period` option was added in file format 2.3. + +`test` must be either a string or a list. If it's a list, the first item must be +either `NONE`, `CMD` or `CMD-SHELL`. If it's a string, it's equivalent to +specifying `CMD-SHELL` followed by that string. + +```yaml +# Hit the local web app +test: ["CMD", "curl", "-f", "http://localhost"] +``` + +As above, but wrapped in `/bin/sh`. Both forms below are equivalent. + +```yaml +test: ["CMD-SHELL", "curl -f http://localhost || exit 1"] +``` + +```yaml +test: curl -f https://localhost || exit 1 +``` + +To disable any default healthcheck set by the image, you can use `disable: true`. +This is equivalent to specifying `test: ["NONE"]`. + +```yaml +healthcheck: + disable: true +``` + +### image + +Specify the image to start the container from. Can either be a repository/tag or +a partial image ID. + +```yaml +image: redis +``` +```yaml +image: ubuntu:22.04 +``` +```yaml +image: tutum/influxdb +``` +```yaml +image: example-registry.com:4000/postgresql +``` +```yaml +image: a4bc65fd +``` + +If the image does not exist, Compose attempts to pull it, unless you have also +specified [build](#build), in which case it builds it using the specified +options and tags it with the specified tag. + +### init + +> Added in [version 2.2](compose-versioning.md#version-22) file format. + +Run an init inside the container that forwards signals and reaps processes. +Set this option to `true` to enable this feature for the service. + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + web: + image: alpine:latest + init: true +``` + +> The default init binary that is used is [Tini](https://github.com/krallin/tini), +> and is installed in `/usr/libexec/docker-init` on the daemon host. You can +> configure the daemon to use a custom init binary through the +> [`init-path` configuration option](../../reference/cli/dockerd.md#daemon-configuration-file). + +### isolation + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Specify a container’s isolation technology. On Linux, the only supported value +is `default`. On Windows, acceptable values are `default`, `process` and +`hyperv`. Refer to the +[Docker Engine docs](../../reference/cli/docker/container/run.md#isolation) +for details. + +### labels + +Add metadata to containers using [Docker labels](../../config/labels-custom-metadata.md). You can use either an array or a dictionary. + +It's recommended that you use reverse-DNS notation to prevent your labels from conflicting with those used by other software. + +```yaml +labels: + com.example.description: "Accounting webapp" + com.example.department: "Finance" + com.example.label-with-empty-value: "" +``` + +```yaml +labels: + - "com.example.description=Accounting webapp" + - "com.example.department=Finance" + - "com.example.label-with-empty-value" +``` + +### links + +Link to containers in another service. Either specify both the service name and +a link alias (`"SERVICE:ALIAS"`), or just the service name. + +> Links are a legacy option. We recommend using +> [networks](#networks) instead. + +```yaml +web: + links: + - "db" + - "db:database" + - "redis" +``` + +Containers for the linked service are reachable at a hostname identical to +the alias, or the service name if no alias was specified. + +Links are not required to enable services to communicate - by default, +any service can reach any other service at that service’s name. (See also, the +[Links topic in Networking in Compose](../networking.md#link-containers).) + +Links also express dependency between services in the same way as +[depends_on](#depends_on), so they determine the order of service startup. + +> **Note** +> +> If you define both links and [networks](#networks), services with +> links between them must share at least one network in common to +> communicate. We recommend using networks instead. + +### logging + +Logging configuration for the service. + +```yaml +logging: + driver: syslog + options: + syslog-address: "tcp://192.168.0.42:123" +``` + +The `driver` name specifies a logging driver for the service's +containers, as with the ``--log-driver`` option for docker run +([documented here](../../config/containers/logging/configure.md)). + +The default value is json-file. + +```yaml +driver: "json-file" +``` +```yaml +driver: "syslog" +``` +```yaml +driver: "none" +``` + +> **Note** +> +> Only the `json-file` and `journald` drivers make the logs available directly +> from `docker-compose up` and `docker-compose logs`. Using any other driver +> does not print any logs. + +Specify logging options for the logging driver with the ``options`` key, as with the ``--log-opt`` option for `docker run`. + +Logging options are key-value pairs. An example of `syslog` options: + +```yaml +driver: "syslog" +options: + syslog-address: "tcp://192.168.0.42:123" +``` + +### network_mode + +> Changed in [version 2](compose-versioning.md#version-2) file format. + +Network mode. Use the same values as the docker client `--network` parameter, plus +the special form `service:[service name]`. + +```yaml +network_mode: "bridge" +``` +```yaml +network_mode: "host" +``` +```yaml +network_mode: "none" +``` +```yaml +network_mode: "service:[service name]" +``` +```yaml +network_mode: "container:[container name/id]" +``` + +### networks + +> Changed in [version 2](compose-versioning.md#version-2) file format. + +Networks to join, referencing entries under the +[top-level `networks` key](#network-configuration-reference). + +```yaml +services: + some-service: + networks: + - some-network + - other-network +``` + +#### aliases + +Aliases (alternative hostnames) for this service on the network. Other containers on the same network can use either the service name or this alias to connect to one of the service's containers. + +Since `aliases` is network-scoped, the same service can have different aliases on different networks. + +> **Note** +> +> A network-wide alias can be shared by multiple containers, and even by multiple +> services. If it is, then exactly which container the name resolves to is not +> guaranteed. + +The general format is shown here. + +```yaml +services: + some-service: + networks: + some-network: + aliases: + - alias1 + - alias3 + other-network: + aliases: + - alias2 +``` + +In the example below, three services are provided (`web`, `worker`, and `db`), +along with two networks (`new` and `legacy`). The `db` service is reachable at +the hostname `db` or `database` on the `new` network, and at `db` or `mysql` on +the `legacy` network. + +```yaml +version: "{{% param "compose_file_v2" %}}" + +services: + web: + image: "nginx:alpine" + networks: + - new + + worker: + image: "my-worker-image:latest" + networks: + - legacy + + db: + image: mysql + networks: + new: + aliases: + - database + legacy: + aliases: + - mysql + +networks: + new: + legacy: +``` + +#### ipv4_address, ipv6_address + +Specify a static IP address for containers for this service when joining the network. + +The corresponding network configuration in the +[top-level networks section](#network-configuration-reference) must have an +`ipam` block with subnet and gateway configurations covering each static address. + +> If IPv6 addressing is desired, the [`enable_ipv6`](#enable_ipv6) option must be set. + +An example: + +```yaml +version: "{{% param "compose_file_v2" %}}" + +services: + app: + image: busybox + command: ifconfig + networks: + app_net: + ipv4_address: 172.16.238.10 + ipv6_address: 2001:3984:3989::10 + +networks: + app_net: + driver: bridge + enable_ipv6: true + ipam: + driver: default + config: + - subnet: 172.16.238.0/24 + gateway: 172.16.238.1 + - subnet: 2001:3984:3989::/64 + gateway: 2001:3984:3989::1 +``` + +#### link_local_ips + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Specify a list of link-local IPs. Link-local IPs are special IPs which belong +to a well known subnet and are purely managed by the operator, usually +dependent on the architecture where they are deployed. Therefore they are not +managed by docker (IPAM driver). + +Example usage: + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + app: + image: busybox + command: top + networks: + app_net: + link_local_ips: + - 57.123.22.11 + - 57.123.22.13 +networks: + app_net: + driver: bridge +``` + +#### priority + +Specify a priority to indicate in which order Compose should connect the +service's containers to its networks. If unspecified, the default value is `0`. + +In the following example, the `app` service connects to `app_net_1` first +as it has the highest priority. It then connects to `app_net_3`, then +`app_net_2`, which uses the default priority value of `0`. + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + app: + image: busybox + command: top + networks: + app_net_1: + priority: 1000 + app_net_2: + + app_net_3: + priority: 100 +networks: + app_net_1: + app_net_2: + app_net_3: +``` + +> **Note** +> +> If multiple networks have the same priority, the connection order is undefined. + +### pid + +```yaml +pid: "host" +``` +```yaml +pid: "container:custom_container_1" +``` +```yaml +pid: "service:foobar" +``` + +If set to one of the following forms: `container:`, +`service:`, the service shares the PID address space of the +designated container or service. + +If set to "host", the service's PID mode is the host PID mode. This turns +on sharing between container and the host operating system the PID address +space. Containers launched with this flag can access and manipulate +other containers in the bare-metal machine's namespace and vice versa. + +> Added in [version 2.1](compose-versioning.md#version-21) file format. +> +> The `service:` and `container:` forms require [version 2.1](compose-versioning.md#version-21) or above + +### pids_limit + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Tunes a container's PIDs limit. Set to `-1` for unlimited PIDs. + +```yaml +pids_limit: 10 +``` + +### platform + +> Added in [version 2.4](compose-versioning.md#version-24) file format. + +Target platform containers for this service will run on, using the +`os[/arch[/variant]]` syntax, e.g. + +```yaml +platform: osx +``` +```yaml +platform: windows/amd64 +``` +```yaml +platform: linux/arm64/v8 +``` + +This parameter determines which version of the image will be pulled and/or +on which platform the service's build will be performed. + +### ports + +Expose ports. Either specify both ports (`HOST:CONTAINER`), or just the container +port (an ephemeral host port is chosen). + +> **Note** +> +> When mapping ports in the `HOST:CONTAINER` format, you may experience +> erroneous results when using a container port lower than 60, because YAML +> parses numbers in the format `xx:yy` as a base-60 value. For this reason, +> we recommend always explicitly specifying your port mappings as strings. + +```yaml +ports: + - "3000" + - "3000-3005" + - "8000:8000" + - "9090-9091:8080-8081" + - "49100:22" + - "127.0.0.1:8001:8001" + - "127.0.0.1:5000-5010:5000-5010" + - "6060:6060/udp" + - "12400-12500:1240" +``` + +### runtime + +> Added in [version 2.3](compose-versioning.md#version-23) file format. + +Specify which runtime to use for the service's containers. Default runtime +and available runtimes are listed in the output of `docker info`. + +```yaml +web: + image: busybox:latest + command: true + runtime: runc +``` + +### scale + +> Added in [version 2.2](compose-versioning.md#version-22) file format. + +Specify the default number of containers to deploy for this service. Whenever +you run `docker-compose up`, Compose creates or removes containers to match +the specified number. This value can be overridden using the +[`--scale`](../../reference/cli/docker/compose/up.md) + +```yaml +web: + image: busybox:latest + command: echo 'scaled' + scale: 3 +``` + +### security_opt + +Override the default labeling scheme for each container. + +```yaml +security_opt: + - label:user:USER + - label:role:ROLE +``` + +### stop_grace_period + +Specify how long to wait when attempting to stop a container if it doesn't +handle SIGTERM (or whatever stop signal has been specified with +[`stop_signal`](#stop_signal)), before sending SIGKILL. Specified +as a [duration](#specifying-durations). + +```yaml +stop_grace_period: 1s +``` + +```yaml +stop_grace_period: 1m30s +``` + +By default, `stop` waits 10 seconds for the container to exit before sending +SIGKILL. + +### stop_signal + +Sets an alternative signal to stop the container. By default `stop` uses +SIGTERM. Setting an alternative signal using `stop_signal` causes +`stop` to send that signal instead. + +```yaml +stop_signal: SIGUSR1 +``` + +### storage_opt + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Set storage driver options for this service. + +```yaml +storage_opt: + size: '1G' +``` + +### sysctls + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Kernel parameters to set in the container. You can use either an array or a +dictionary. + +```yaml +sysctls: + net.core.somaxconn: 1024 + net.ipv4.tcp_syncookies: 0 +``` + +```yaml +sysctls: + - net.core.somaxconn=1024 + - net.ipv4.tcp_syncookies=0 +``` + +### tmpfs + +Mount a temporary file system inside the container. Can be a single value or a list. + +```yaml +tmpfs: /run +``` + +```yaml +tmpfs: + - /run + - /tmp +``` + +### ulimits + +Override the default ulimits for a container. You can either specify a single +limit as an integer or soft/hard limits as a mapping. + +```yaml +ulimits: + nproc: 65535 + nofile: + soft: 20000 + hard: 40000 +``` + +### userns_mode + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +```yaml +userns_mode: "host" +``` + +Disables the user namespace for this service, if Docker daemon is configured with user namespaces. +See [dockerd](../../engine/security/userns-remap.md#disable-namespace-remapping-for-a-container) for +more information. + +### volumes + +Mount host paths or named volumes. Named volumes need to be specified with the +[top-level `volumes` key](#volume-configuration-reference). + +#### Short syntax + +The short syntax uses the generic `[SOURCE:]TARGET[:MODE]` format, where +`SOURCE` can be either a host path or volume name. `TARGET` is the container +path where the volume is mounted. Standard modes are `ro` for read-only +and `rw` for read-write (default). + +You can mount a relative path on the host, which expands relative to +the directory of the Compose configuration file being used. Relative paths +should always begin with `.` or `..`. + +```yaml +volumes: + # Just specify a path and let the Engine create a volume + - /var/lib/mysql + + # Specify an absolute path mapping + - /opt/data:/var/lib/mysql + + # Path on the host, relative to the Compose file + - ./cache:/tmp/cache + + # User-relative path + - ~/configs:/etc/configs/:ro + + # Named volume + - datavolume:/var/lib/mysql +``` + +#### Long syntax + +> Added in [version 2.3](compose-versioning.md#version-23) file format. + +The long form syntax allows the configuration of additional fields that can't be +expressed in the short form. + +- `type`: the mount type `volume`, `bind`, `tmpfs` or `npipe` +- `source`: the source of the mount, a path on the host for a bind mount, or the + name of a volume defined in the + [top-level `volumes` key](#volume-configuration-reference). Not applicable for a tmpfs mount. +- `target`: the path in the container where the volume is mounted +- `read_only`: flag to set the volume as read-only +- `bind`: configure additional bind options + - `propagation`: the propagation mode used for the bind +- `volume`: configure additional volume options + - `nocopy`: flag to disable copying of data from a container when a volume is + created +- `tmpfs`: configure additional tmpfs options + - `size`: the size for the tmpfs mount in bytes + + +```yaml +version: "{{% param "compose_file_v2" %}}" +services: + web: + image: nginx:alpine + ports: + - "80:80" + volumes: + - type: volume + source: mydata + target: /data + volume: + nocopy: true + - type: bind + source: ./static + target: /opt/app/static + +networks: + webnet: + +volumes: + mydata: +``` + +> **Note** +> +> When creating bind mounts, using the long syntax requires the +> referenced folder to be created beforehand. Using the short syntax +> creates the folder on the fly if it doesn't exist. +> See the [bind mounts documentation](../../storage/bind-mounts.md#differences-between--v-and---mount-behavior) +> for more information. + +### volume\_driver + +Specify a default volume driver to be used for all declared volumes on this +service. + +```yaml +volume_driver: mydriver +``` + +> **Note** +> +> In [version 2 files](compose-versioning.md#version-2), this +> option only applies to anonymous volumes (those specified in the image, +> or specified under `volumes` without an explicit named volume or host path). +> To configure the driver for a named volume, use the `driver` key under the +> entry in the [top-level `volumes` option](#volume-configuration-reference). + + +See [Docker Volumes](../../storage/volumes.md) and +[Volume Plugins](/engine/extend/plugins_volume/) for more information. + +### volumes_from + +Mount all of the volumes from another service or container, optionally +specifying read-only access (``ro``) or read-write (``rw``). If no access level +is specified, then read-write is used. + +```yaml +volumes_from: + - service_name + - service_name:ro + - container:container_name + - container:container_name:rw +``` + +> Changed in [version 2](compose-versioning.md#version-2) file format. + +### restart + +`no` is the default restart policy, and it doesn't restart a container under any circumstance. When `always` is specified, the container always restarts. The `on-failure` policy restarts a container if the exit code indicates an on-failure error. + +```yaml +restart: "no" +``` +```yaml +restart: "always" +``` +```yaml +restart: "on-failure" +``` +```yaml +restart: "unless-stopped" +``` + +{ #cpu-and-other-resources } + +### cpu_count, cpu_percent, cpu\_shares, cpu\_period, cpu\_quota, cpus, cpuset, domainname, hostname, ipc, mac\_address, mem\_limit, memswap\_limit, mem\_swappiness, mem\_reservation, oom_kill_disable, oom_score_adj, privileged, read\_only, shm\_size, stdin\_open, tty, user, working\_dir + +Each of these is a single value, analogous to its +[docker run](../../reference/cli/docker/container/run.md#runtime-constraints-on-resources) counterpart. + +> Added in [version 2.2](compose-versioning.md#version-22) file format. +> +> The `cpu_count`, `cpu_percent`, and `cpus` options were added in [version 2.2](compose-versioning.md#version-22). + +> Added in [version 2.1](compose-versioning.md#version-21) file format. +> +> The `oom_kill_disable` and `cpu_period` options were added in [version 2.1](compose-versioning.md#version-21). + +```yaml +cpu_count: 2 +cpu_percent: 50 +cpus: 0.5 +cpu_shares: 73 +cpu_quota: 50000 +cpu_period: 20ms +cpuset: 0,1 + +user: postgresql +working_dir: /code + +domainname: foo.com +hostname: foo +ipc: host +mac_address: 02:42:ac:11:65:43 + +mem_limit: 1000000000 +memswap_limit: 2000000000 +mem_reservation: 512m +privileged: true + +oom_score_adj: 500 +oom_kill_disable: true + +read_only: true +shm_size: 64M +stdin_open: true +tty: true +``` + + + +## Specifying durations + +Some configuration options, such as the `interval` and `timeout` sub-options for +[`healthcheck`](#healthcheck), accept a duration as a string in a +format that looks like this: + + 2.5s + 10s + 1m30s + 2h32m + 5h34m56s + +The supported units are `us`, `ms`, `s`, `m` and `h`. + +## Specifying byte values + +Some configuration options, such as the `device_read_bps` sub-option for +[`blkio_config`](#blkio_config), accept a byte value as a string in a format +that looks like this: + + 2b + 1024kb + 2048k + 300m + 1gb + +The supported units are `b`, `k`, `m` and `g`, and their alternative notation `kb`, +`mb` and `gb`. Decimal values are not supported at this time. + +## Volume configuration reference + +While it is possible to declare [volumes](#volumes) on the fly as part of the +service declaration, this section allows you to create named volumes that can be +reused across multiple services (without relying on `volumes_from`), and are +easily retrieved and inspected using the docker command line or API. +See the [docker volume](../../reference/cli/docker/volume/create.md) +subcommand documentation for more information. + +See [use volumes](../../storage/volumes.md) and [volume plugins](/engine/extend/plugins_volume/) +for general information on volumes. + +Here's an example of a two-service setup where a database's data directory is +shared with another service as a volume so that it can be periodically backed +up: + +```yaml +version: "{{% param "compose_file_v2" %}}" + +services: + db: + image: db + volumes: + - data-volume:/var/lib/db + backup: + image: backup-service + volumes: + - data-volume:/var/lib/backup/data + +volumes: + data-volume: +``` + +An entry under the top-level `volumes` key can be empty, in which case it +uses the default driver configured by the Engine (in most cases, this is the +`local` driver). Optionally, you can configure it with the following keys: + +### driver + +Specify which volume driver should be used for this volume. Defaults to whatever +driver the Docker Engine has been configured to use, which in most cases is +`local`. If the driver is not available, the Engine returns an error when +`docker-compose up` tries to create the volume. + +```yaml +driver: foobar +``` + +### driver_opts + +Specify a list of options as key-value pairs to pass to the driver for this +volume. Those options are driver-dependent - consult the driver's +documentation for more information. Optional. + +```yaml +volumes: + example: + driver_opts: + type: "nfs" + o: "addr=10.40.0.199,nolock,soft,rw" + device: ":/docker/example" +``` + +### external + +If set to `true`, specifies that this volume has been created outside of +Compose. `docker-compose up` does not attempt to create it, and raises +an error if it doesn't exist. + +For version 2.0 of the format, `external` cannot be used in +conjunction with other volume configuration keys (`driver`, `driver_opts`, +`labels`). This limitation no longer exists for +[version 2.1](compose-versioning.md#version-21) and above. + +In the example below, instead of attempting to create a volume called +`[projectname]_data`, Compose looks for an existing volume simply +called `data` and mount it into the `db` service's containers. + +```yaml +version: "{{% param "compose_file_v2" %}}" + +services: + db: + image: postgres + volumes: + - data:/var/lib/postgresql/data + +volumes: + data: + external: true +``` + +You can also specify the name of the volume separately from the name used to +refer to it within the Compose file: + +```yaml +volumes: + data: + external: + name: actual-name-of-volume +``` + +> Deprecated in [version 2.1](compose-versioning.md#version-21) file format. +> +> external.name was deprecated in version 2.1 file format use `name` instead. +{ .important } + +### labels + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Add metadata to containers using +[Docker labels](../../config/labels-custom-metadata.md). You can use either +an array or a dictionary. + +It's recommended that you use reverse-DNS notation to prevent your labels from +conflicting with those used by other software. + +```yaml +labels: + com.example.description: "Database volume" + com.example.department: "IT/Ops" + com.example.label-with-empty-value: "" +``` + +```yaml +labels: + - "com.example.description=Database volume" + - "com.example.department=IT/Ops" + - "com.example.label-with-empty-value" +``` + +### name + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Set a custom name for this volume. The name field can be used to reference +volumes that contain special characters. The name is used as is +and will **not** be scoped with the stack name. + +```yaml +version: "{{% param "compose_file_v2" %}}" +volumes: + data: + name: my-app-data +``` + +It can also be used in conjunction with the `external` property: + +```yaml +version: "{{% param "compose_file_v2" %}}" +volumes: + data: + external: true + name: my-app-data +``` + +## Network configuration reference + +The top-level `networks` key lets you specify networks to be created. For a full +explanation of Compose's use of Docker networking features, see the +[Networking guide](../networking.md). + +### driver + +Specify which driver should be used for this network. + +The default driver depends on how the Docker Engine you're using is configured, +but in most instances it is `bridge` on a single host and `overlay` on a +Swarm. + +The Docker Engine returns an error if the driver is not available. + +```yaml +driver: overlay +``` + +> Changed in [version 2.1](compose-versioning.md#version-21) file format. +> +> Starting with Compose file format 2.1, overlay networks are always created as +> `attachable`, and this is not configurable. This means that standalone +> containers can connect to overlay networks. + +### driver_opts + +Specify a list of options as key-value pairs to pass to the driver for this +network. Those options are driver-dependent - consult the driver's +documentation for more information. Optional. + +```yaml +driver_opts: + foo: "bar" + baz: 1 +``` + +### enable_ipv6 + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Enable IPv6 networking on this network. + +### ipam + +Specify custom IPAM config. This is an object with several properties, each of +which is optional: + +- `driver`: Custom IPAM driver, instead of the default. +- `config`: A list with zero or more config blocks, each containing any of + the following keys: + - `subnet`: Subnet in CIDR format that represents a network segment + - `ip_range`: Range of IPs from which to allocate container IPs + - `gateway`: IPv4 or IPv6 gateway for the master subnet + - `aux_addresses`: Auxiliary IPv4 or IPv6 addresses used by Network driver, + as a mapping from hostname to IP +- `options`: Driver-specific options as a key-value mapping. + +A full example: + +```yaml +ipam: + driver: default + config: + - subnet: 172.28.0.0/16 + ip_range: 172.28.5.0/24 + gateway: 172.28.5.254 + aux_addresses: + host1: 172.28.1.5 + host2: 172.28.1.6 + host3: 172.28.1.7 + options: + foo: bar + baz: "0" +``` + +### internal + +By default, Docker also connects a bridge network to it to provide external +connectivity. If you want to create an externally isolated overlay network, +you can set this option to `true`. + +### labels + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Add metadata to containers using +[Docker labels](../../config/labels-custom-metadata.md). You can use either +an array or a dictionary. + +It's recommended that you use reverse-DNS notation to prevent your labels from +conflicting with those used by other software. + +```yaml +labels: + com.example.description: "Financial transaction network" + com.example.department: "Finance" + com.example.label-with-empty-value: "" +``` + +```yaml +labels: + - "com.example.description=Financial transaction network" + - "com.example.department=Finance" + - "com.example.label-with-empty-value" +``` + +### external + +If set to `true`, specifies that this network has been created outside of +Compose. `docker-compose up` does not attempt to create it, and raises +an error if it doesn't exist. + +For version 2.0 of the format, `external` cannot be used in conjunction with +other network configuration keys (`driver`, `driver_opts`, `ipam`, `internal`). +This limitation no longer exists for +[version 2.1](compose-versioning.md#version-21) and above. + +In the example below, `proxy` is the gateway to the outside world. Instead of +attempting to create a network called `[projectname]_outside`, Compose +looks for an existing network simply called `outside` and connect the `proxy` +service's containers to it. + +```yaml +version: "{{% param "compose_file_v2" %}}" + +services: + proxy: + build: ./proxy + networks: + - outside + - default + app: + build: ./app + networks: + - default + +networks: + outside: + external: true +``` + +You can also specify the name of the network separately from the name used to +refer to it within the Compose file: + +```yaml +version: "{{% param "compose_file_v2" %}}" +networks: + outside: + external: + name: actual-name-of-network +``` + +Not supported for version 2 `docker-compose` files. Use +[network_mode](#network_mode) instead. + +### name + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +Set a custom name for this network. The name field can be used to reference +networks which contain special characters. The name is used as is +and will **not** be scoped with the stack name. + +```yaml +version: "{{% param "compose_file_v2" %}}" +networks: + network1: + name: my-app-net +``` + +It can also be used in conjunction with the `external` property: + +```yaml +version: "{{% param "compose_file_v2" %}}" +networks: + network1: + external: true + name: my-app-net +``` + +## Variable substitution + +{{< include "content/compose-var-sub.md" >}} + +## Extension fields + +> Added in [version 2.1](compose-versioning.md#version-21) file format. + +{{< include "content/compose-extfields-sub.md" >}} diff --git a/docs/Compose file reference/version-3.md b/docs/Compose file reference/version-3.md new file mode 100644 index 0000000000..e69de29bb2 From 5cae818267af5e89010bae8318c98dda1b9fad32 Mon Sep 17 00:00:00 2001 From: aevesdocker Date: Wed, 1 May 2024 12:07:06 +0100 Subject: [PATCH 2/2] Change links and add versioning information Signed-off-by: aevesdocker --- .../compose-versioning.md | 474 +++ .../version-2.md | 227 +- .../version-3.md | 2913 +++++++++++++++++ docs/Compose file reference/version-3.md | 0 docs/README.md | 14 - 5 files changed, 3585 insertions(+), 43 deletions(-) create mode 100644 docs/Compose file reference (legacy)/compose-versioning.md rename docs/{Compose file reference => Compose file reference (legacy)}/version-2.md (84%) create mode 100644 docs/Compose file reference (legacy)/version-3.md delete mode 100644 docs/Compose file reference/version-3.md delete mode 100644 docs/README.md diff --git a/docs/Compose file reference (legacy)/compose-versioning.md b/docs/Compose file reference (legacy)/compose-versioning.md new file mode 100644 index 0000000000..63acae76ec --- /dev/null +++ b/docs/Compose file reference (legacy)/compose-versioning.md @@ -0,0 +1,474 @@ +There are three legacy versions of the Compose file format: + +- Version 1. This is specified by omitting a `version` key at the root of the YAML. + +- Version 2.x. This is specified with a `version: '2'` or `version: '2.1'`, etc., entry at the root of the YAML. + +- Version 3.x, designed to be cross-compatible between Compose and the Docker Engine's +[swarm mode](https://docs.docker.com/engine/swarm/). This is specified with a `version: '3'` or `version: '3.1'`, etc., entry at the root of the YAML. + +The latest and recommended version of the Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/). This format merges the 2.x and 3.x versions and is implemented by **Compose 1.27.0+**. + + +> **Note** +> +> If you're using [multiple Compose files](https://docs.docker.com/compose/multiple-compose-files/) or +> [extending services](https://docs.docker.com/compose/multiple-compose-files/extends/), +> each file must be of the same version - you cannot, for example, +> mix version 1 and 2 in a single project. + +Several things differ depending on which version you use: + +- The structure and permitted configuration keys +- The minimum Docker Engine version you must be running +- Compose's behaviour with regards to networking + +These differences are explained below. + +### Version 2 + +Compose files using the version 2 syntax must indicate the version number at +the root of the document. All [services](compose-file-v2.md#service-configuration-reference) +must be declared under the `services` key. + +Version 2 files are supported by **Compose 1.6.0+** and require a Docker Engine +of version **1.10.0+**. + +Named [volumes](compose-file-v2.md#volume-configuration-reference) can be declared under the +`volumes` key, and [networks](compose-file-v2.md#network-configuration-reference) can be declared +under the `networks` key. + +By default, every container joins an application-wide default network, and is +discoverable at a hostname that's the same as the service name. This means +[links](compose-file-v2.md#links) are largely unnecessary. For more details, see +[Networking in Compose](https://docs.docker.com/compose/networking/). + +> **Note** +> +> With Compose version 2, when specifying the Compose file version to use, make sure to +> specify both the _major_ and _minor_ numbers. If no minor version is given, +> `0` is used by default and not the latest minor version. As a result, features added in later versions will not be supported. For example: +> +> ```yaml +> version: "2" +> ``` +> +> is equivalent to: +> +> ```yaml +> version: "2.0" +> ``` + +Simple example: + + version: "{{% param "compose_file_v2" %}}" + services: + web: + build: . + ports: + - "8000:5000" + volumes: + - .:/code + redis: + image: redis + +A more extended example, defining volumes and networks: + + version: "{{% param "compose_file_v2" %}}" + services: + web: + build: . + ports: + - "8000:5000" + volumes: + - .:/code + networks: + - front-tier + - back-tier + redis: + image: redis + volumes: + - redis-data:/var/lib/redis + networks: + - back-tier + volumes: + redis-data: + driver: local + networks: + front-tier: + driver: bridge + back-tier: + driver: bridge + +Several other options were added to support networking, such as: + +* [`aliases`](compose-file-v2.md#aliases) + +* The [`depends_on`](compose-file-v2.md#depends_on) option can be used in place of links to indicate dependencies +between services and startup order. + + version: "{{% param "compose_file_v2" %}}" + services: + web: + build: . + depends_on: + - db + - redis + redis: + image: redis + db: + image: postgres + +* [`ipv4_address`, `ipv6_address`](compose-file-v2.md#ipv4_address-ipv6_address) + +[Variable substitution](compose-file-v2.md#variable-substitution) also was added in Version 2. + +### Version 2.1 + +An upgrade of [version 2](#version-2) that introduces new parameters only +available with Docker Engine version **1.12.0+**. Version 2.1 files are +supported by **Compose 1.9.0+**. + +Introduces the following additional parameters: + +- [`link_local_ips`](compose-file-v2.md#link_local_ips) +- [`isolation`](compose-file-v2.md#isolation-1) in build configurations and + service definitions +- `labels` for [volumes](compose-file-v2.md#volume-configuration-reference), + [networks](compose-file-v2.md#network-configuration-reference), and + [build](compose-file-v3.md#build) +- `name` for [volumes](compose-file-v2.md#volume-configuration-reference) +- [`userns_mode`](compose-file-v2.md#userns_mode) +- [`healthcheck`](compose-file-v2.md#healthcheck) +- [`sysctls`](compose-file-v2.md#sysctls) +- [`pids_limit`](compose-file-v2.md#pids_limit) +- [`oom_kill_disable`](compose-file-v2.md#cpu-and-other-resources) +- [`cpu_period`](compose-file-v2.md#cpu-and-other-resources) + +### Version 2.2 + +An upgrade of [version 2.1](#version-21) that introduces new parameters only +available with Docker Engine version **1.13.0+**. Version 2.2 files are +supported by **Compose 1.13.0+**. This version also allows you to specify +default scale numbers inside the service's configuration. + +Introduces the following additional parameters: + +- [`init`](compose-file-v2.md#init) +- [`scale`](compose-file-v2.md#scale) +- [`cpu_rt_runtime` and `cpu_rt_period`](compose-file-v2.md#cpu_rt_runtime-cpu_rt_period) +- [`network`](compose-file-v2.md#network) for [build configurations](compose-file-v2.md#build) + +### Version 2.3 + +An upgrade of [version 2.2](#version-22) that introduces new parameters only +available with Docker Engine version **17.06.0+**. Version 2.3 files are +supported by **Compose 1.16.0+**. + +Introduces the following additional parameters: + +- [`target`](compose-file-v2.md#target), [`extra_hosts`](compose-file-v2.md#extra_hosts-1) and + [`shm_size`](compose-file-v2.md#shm_size) for [build configurations](compose-file-v2.md#build) +- `start_period` for [`healthchecks`](compose-file-v2.md#healthcheck) +- ["Long syntax" for volumes](compose-file-v2.md#long-syntax) +- [`runtime`](compose-file-v2.md#runtime) for service definitions +- [`device_cgroup_rules`](compose-file-v2.md#device_cgroup_rules) + +### Version 2.4 + +An upgrade of [version 2.3](#version-23) that introduces new parameters only +available with Docker Engine version **17.12.0+**. Version 2.4 files are +supported by **Compose 1.21.0+**. + +Introduces the following additional parameters: + +- [`platform`](compose-file-v2.md#platform) for service definitions +- Support for extension fields at the root of service, network, and volume + definitions + +### Version 3 + +Designed to be cross-compatible between Compose and the Docker Engine's +[swarm mode](/engine/swarm/), version 3 removes several options and adds +several more. + +- Removed: `volume_driver`, `volumes_from`, `cpu_shares`, `cpu_quota`, + `cpuset`, `mem_limit`, `memswap_limit`, `extends`, `group_add`. See + the [upgrading](#upgrading) guide for how to migrate away from these. + +- Added: [deploy](compose-file-v3.md#deploy) + +If only the major version is given (`version: '3'`), +the latest minor version is used by default. + +### Version 3.1 + +An upgrade of [version 3](#version-3) that introduces new parameters only +available with Docker Engine version **1.13.1+**, and higher. + +Introduces the following additional parameters: + +- [`secrets`](compose-file-v3.md#secrets) + +### Version 3.2 + +An upgrade of [version 3](#version-3) that introduces new parameters only +available with Docker Engine version **17.04.0+**, and higher. + +Introduces the following additional parameters: + +- [`cache_from`](compose-file-v3.md#cache_from) in [build configurations](compose-file-v3.md#build) +- Long syntax for [ports](compose-file-v3.md#ports) and [volume mounts](compose-file-v3.md#volumes) +- [`attachable`](compose-file-v3.md#attachable) network driver option +- [deploy `endpoint_mode`](compose-file-v3.md#endpoint_mode) +- [deploy placement `preference`](compose-file-v3.md#placement) + +### Version 3.3 + +An upgrade of [version 3](#version-3) that introduces new parameters only +available with Docker Engine version **17.06.0+**, and higher. + +Introduces the following additional parameters: + +- [build `labels`](compose-file-v3.md#build) +- [`credential_spec`](compose-file-v3.md#credential_spec) +- [`configs`](compose-file-v3.md#configs) + +### Version 3.4 + +An upgrade of [version 3](#version-3) that introduces new parameters. It is +only available with Docker Engine version **17.09.0** and higher. + +Introduces the following additional parameters: + +- [`target`](compose-file-v3.md#target) and [`network`](compose-file-v3.md#network) in + [build configurations](compose-file-v3.md#build) +- `start_period` for [`healthchecks`](compose-file-v3.md#healthcheck) +- `order` for [update configurations](compose-file-v3.md#update_config) +- `name` for [volumes](compose-file-v3.md#volume-configuration-reference) + +### Version 3.5 + +An upgrade of [version 3](#version-3) that introduces new parameters. It is +only available with Docker Engine version **17.12.0** and higher. + +Introduces the following additional parameters: + +- [`isolation`](compose-file-v3.md#isolation) in service definitions +- `name` for networks, secrets and configs +- `shm_size` in [build configurations](compose-file-v3.md#build) + +### Version 3.6 + +An upgrade of [version 3](#version-3) that introduces new parameters. It is +only available with Docker Engine version **18.02.0** and higher. + +Introduces the following additional parameters: + +- [`tmpfs` size](compose-file-v3.md#long-syntax-3) for `tmpfs`-type mounts + +### Version 3.7 + +An upgrade of [version 3](#version-3) that introduces new parameters. It is +only available with Docker Engine version **18.06.0** and higher. + +Introduces the following additional parameters: + +- [`init`](compose-file-v3.md#init) in service definitions +- [`rollback_config`](compose-file-v3.md#rollback_config) in deploy configurations +- Support for extension fields at the root of service, network, volume, secret + and config definitions + +### Version 3.8 + +An upgrade of [version 3](#version-3) that introduces new parameters. It is +only available with Docker Engine version **19.03.0** and higher. + +Introduces the following additional parameters: + +- [`max_replicas_per_node`](compose-file-v3.md#max_replicas_per_node) in placement + configurations +- `template_driver` option for [config](compose-file-v3.md#configs-configuration-reference) + and [secret](compose-file-v3.md#secrets-configuration-reference) configurations. This + option is only supported when deploying swarm services using + `docker stack deploy`. +- `driver` and `driver_opts` option for [secret](compose-file-v3.md#secrets-configuration-reference) + configurations. This option is only supported when deploying swarm services + using `docker stack deploy`. + +### Version 1 (Deprecated) + +Compose versions below 1.6.x are + +Compose files that do not declare a version are considered "version 1". In those +files, all the [services](compose-file-v3.md#service-configuration-reference) are +declared at the root of the document. + +Version 1 is supported by Compose up to 1.6.x** and has been deprecated. + +Version 1 files cannot declare named +[volumes](compose-file-v3.md#volume-configuration-reference), [networks](compose-file-v3.md#network-configuration-reference) or +[build arguments](compose-file-v3.md#args). + +Compose does not take advantage of [networking](https://docs.docker.com/compose/networking/) when you +use version 1: every container is placed on the default `bridge` network and is +reachable from every other container at its IP address. You need to use +`links` to enable discovery between containers. + +Example: + + web: + build: . + ports: + - "8000:5000" + volumes: + - .:/code + links: + - redis + redis: + image: redis + +## Upgrading + +### Version 2.x to 3.x + +Between versions 2.x and 3.x, the structure of the Compose file is the same, but +several options have been removed: + +- `volume_driver`: Instead of setting the volume driver on the service, define + a volume using the + [top-level `volumes` option](compose-file-v3.md#volume-configuration-reference) + and specify the driver there. + + version: "3.8" + services: + db: + image: postgres + volumes: + - data:/var/lib/postgresql/data + volumes: + data: + driver: mydriver + +- `volumes_from`: To share a volume between services, define it using the + [top-level `volumes` option](compose-file-v3.md#volume-configuration-reference) + and reference it from each service that shares it using the + [service-level `volumes` option](compose-file-v3.md#driver). + +- `cpu_shares`, `cpu_quota`, `cpuset`, `mem_limit`, `memswap_limit`: These + have been replaced by the [resources](compose-file-v3.md#resources) key under + `deploy`. `deploy` configuration only takes effect when using + `docker stack deploy`, and is ignored by `docker-compose`. + +- `extends`: This option has been removed for `version: "3.x"` Compose files. + For more information on `extends`, see + [Extending services](https://docs.docker.com/compose/multiple-compose-files/extends/). +- `group_add`: This option has been removed for `version: "3.x"` Compose files. +- `pids_limit`: This option has not been introduced in `version: "3.x"` Compose files. +- `link_local_ips` in `networks`: This option has not been introduced in + `version: "3.x"` Compose files. + +#### Compatibility mode + +`docker-compose` 1.20.0 introduces a new `--compatibility` flag designed to +help developers transition to version 3 more easily. When enabled, +`docker-compose` reads the `deploy` section of each service's definition and +attempts to translate it into the equivalent version 2 parameter. Currently, +the following deploy keys are translated: + +- [resources](compose-file-v3.md#resources) limits and memory reservations +- [replicas](compose-file-v3.md#replicas) +- [restart_policy](compose-file-v3.md#restart_policy) `condition` and `max_attempts` + +All other keys are ignored and produce a warning if present. You can review +the configuration that will be used to deploy by using the `--compatibility` +flag with the `config` command. + +> Do not use this in production +> +> We recommend against using `--compatibility` mode in production. The +> resulting configuration is only an approximate using non-Swarm mode +> properties, it may produce unexpected results. + +### Version 1 to 2.x + +In the majority of cases, moving from version 1 to 2 is a very simple process: + +1. Indent the whole file by one level and put a `services:` key at the top. +2. Add a `version: '2'` line at the top of the file. + +It's more complicated if you're using particular configuration features: + +- `dockerfile`: This now lives under the `build` key: + + build: + context: . + dockerfile: Dockerfile-alternate + +- `log_driver`, `log_opt`: These now live under the `logging` key: + + logging: + driver: syslog + options: + syslog-address: "tcp://192.168.0.42:123" + +- `links` with environment variables: environment variables created by + links, such as `CONTAINERNAME_PORT`, ` have been deprecated for some time. In the new Docker network system, + they have been removed. You should either connect directly to the + appropriate hostname or set the relevant environment variable yourself, + using the link hostname: + + web: + links: + - db + environment: + - DB_PORT=tcp://db:5432 + +- `external_links`: Compose uses Docker networks when running version 2 + projects, so links behave slightly differently. In particular, two + containers must be connected to at least one network in common in order to + communicate, even if explicitly linked together. + + Either connect the external container to your app's + [default network](https://docs.docker.com/compose/networking/), or connect both the external container and + your service's containers to an + [external network](https://docs.docker.com/compose/networking/). + +- `net`: This is now replaced by [network_mode](compose-file-v3.md#network_mode): + + net: host -> network_mode: host + net: bridge -> network_mode: bridge + net: none -> network_mode: none + + If you're using `net: "container:[service name]"`, you must now use + `network_mode: "service:[service name]"` instead. + + net: "container:web" -> network_mode: "service:web" + + If you're using `net: "container:[container name/id]"`, the value does not + need to change. + + net: "container:cont-name" -> network_mode: "container:cont-name" + net: "container:abc12345" -> network_mode: "container:abc12345" + +- `volumes` with named volumes: these must now be explicitly declared in a + top-level `volumes` section of your Compose file. If a service mounts a + named volume called `data`, you must declare a `data` volume in your + top-level `volumes` section. The whole file might look like this: + + version: "{{% param "compose_file_v2" %}}" + services: + db: + image: postgres + volumes: + - data:/var/lib/postgresql/data + volumes: + data: {} + + By default, Compose creates a volume whose name is prefixed with your + project name. If you want it to just be called `data`, declare it as + external: + + volumes: + data: + external: true diff --git a/docs/Compose file reference/version-2.md b/docs/Compose file reference (legacy)/version-2.md similarity index 84% rename from docs/Compose file reference/version-2.md rename to docs/Compose file reference (legacy)/version-2.md index 7865755317..0d3eb6c064 100644 --- a/docs/Compose file reference/version-2.md +++ b/docs/Compose file reference (legacy)/version-2.md @@ -1,4 +1,6 @@ -These topics describe version 2 of the Compose file format. +This page describes version 2 of the Compose file format. + +This is legacy content. The latest Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/) and is implemented by Docker Compose **1.27.0+**. ## Compose and Docker compatibility matrix @@ -6,7 +8,33 @@ There are several versions of the Compose file format – 1, 2, 2.x, and 3.x. Th table below is a quick look. For full details on what each version includes and how to upgrade, see **[About versions and upgrading](compose-versioning.md)**. -{{< include "content/compose-matrix.md" >}} +This table shows which Compose file versions support specific Docker releases. + +| **Compose file format** | **Docker Engine release** | +| ------------------- | ------------------ | +| Compose specification | 19.03.0+ | +| 3.8 | 19.03.0+ | +| 3.7 | 18.06.0+ | +| 3.6 | 18.02.0+ | +| 3.5 | 17.12.0+ | +| 3.4 | 17.09.0+ | +| 3.3 | 17.06.0+ | +| 3.2 | 17.04.0+ | +| 3.1 | 1.13.1+ | +| 3.0 | 1.13.0+ | +| 2.4 | 17.12.0+ | +| 2.3 | 17.06.0+ | +| 2.2 | 1.13.0+ | +| 2.1 | 1.12.0+ | +| 2.0 | 1.10.0+ | + +In addition to Compose file format versions shown in the table, the Compose +itself is on a release schedule, as shown in [Compose +releases](https://github.com/docker/compose/releases/), but file format versions +do not necessarily increment with each release. For example, Compose file format +3.0 was first introduced in [Compose release +1.10.0](https://github.com/docker/compose/releases/tag/1.10.0), and versioned +gradually in subsequent releases. ## Service configuration reference @@ -205,7 +233,7 @@ build: > In your Dockerfile, if you specify `ARG` before the `FROM` instruction, > `ARG` is not available in the build instructions under `FROM`. > If you need an argument to be available in both places, also specify it under -> the `FROM` instruction. Refer to the [understand how ARGS and FROM interact](../../reference/dockerfile.md#understand-how-arg-and-from-interact) +> the `FROM` instruction. Refer to the [understand how ARGS and FROM interact](https://docs.docker.com/reference/dockerfile#understand-how-arg-and-from-interact) > section in the documentation for usage details. You can omit the value when specifying a build argument, in which case its value @@ -261,7 +289,7 @@ An entry with the ip address and hostname is created in `/etc/hosts` inside cont Specify a build’s container isolation technology. On Linux, the only supported value is `default`. On Windows, acceptable values are `default`, `process` and `hyperv`. Refer to the -[Docker Engine docs](../../reference/cli/docker/container/run.md#isolation) +[Docker Engine docs](https://docs.docker.com/reference/cli/docker/container/run#isolation) for details. If unspecified, Compose will use the `isolation` value found in the service's definition @@ -271,7 +299,7 @@ to determine the value to use for builds. > Added in [version 2.1](compose-versioning.md#version-21) file format -Add metadata to the resulting image using [Docker labels](../../config/labels-custom-metadata.md). +Add metadata to the resulting image using [Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either an array or a dictionary. It's recommended that you use reverse-DNS notation to prevent your labels from @@ -347,7 +375,7 @@ build: > Added in [version 2.3](compose-versioning.md#version-23) file format Build the specified stage as defined inside the `Dockerfile`. See the -[multi-stage build docs](../../build/building/multi-stage.md) for +[multi-stage build docs](https://docs.docker.com/build/building/multi-stage) for details. ```yaml @@ -387,7 +415,7 @@ command: bundle exec thin -p 3000 ``` The command can also be a list, in a manner similar to -[dockerfile](../../reference/dockerfile.md#cmd): +[dockerfile](https://docs.docker.com/reference/dockerfile#cmd): ```yaml command: ["bundle", "exec", "thin", "-p", "3000"] @@ -480,7 +508,7 @@ services: > > `depends_on` does not wait for `db` and `redis` to be "ready" before > starting `web` - only until they have been started. If you need to wait -> for a service to be ready, see [Controlling startup order](../startup-order.md) +> for a service to be ready, see [Controlling startup order](https://docs.docker.com/compose/startup-order/) > for more on this problem and strategies for solving it. > Added in [version 2.1](compose-versioning.md#version-21) file format. @@ -562,7 +590,7 @@ entrypoint: /code/entrypoint.sh ``` The entrypoint can also be a list, in a manner similar to -[dockerfile](../../reference/dockerfile.md#entrypoint): +[dockerfile](https://docs.docker.com/reference/dockerfile#entrypoint): ```yaml entrypoint: ["php", "-d", "memory_limit=-1", "vendor/bin/phpunit"] @@ -718,7 +746,7 @@ indefinitely. Compose does not support circular references and `docker-compose` returns an error if it encounters one. For more on `extends`, see the -[the extends documentation](../multiple-compose-files/extends.md) +[the extends documentation](https://docs.docker.com/compose/multiple-compose-files/extends) ### external_links @@ -766,7 +794,7 @@ host system to be added. An example of where this is useful is when multiple containers (running as different users) need to all read or write the same file on the host system. That file can be owned by a group shared by all the containers, and specified in `group_add`. See the -[Docker documentation](../../reference/cli/docker/container/run.md#additional-groups) for more +[Docker documentation](https://docs.docker.com/reference/cli/docker/container/run#additional-groups) for more details. A full example: @@ -790,7 +818,7 @@ used. Configure a check that's run to determine whether or not containers for this service are "healthy". See the docs for the -[HEALTHCHECK Dockerfile instruction](../../reference/dockerfile.md#healthcheck) +[HEALTHCHECK Dockerfile instruction](https://docs.docker.com/reference/dockerfile#healthcheck) for details on how healthchecks work. ```yaml @@ -879,7 +907,7 @@ services: > The default init binary that is used is [Tini](https://github.com/krallin/tini), > and is installed in `/usr/libexec/docker-init` on the daemon host. You can > configure the daemon to use a custom init binary through the -> [`init-path` configuration option](../../reference/cli/dockerd.md#daemon-configuration-file). +> [`init-path` configuration option](https://docs.docker.com/reference/cli/dockerd#daemon-configuration-file). ### isolation @@ -888,12 +916,12 @@ services: Specify a container’s isolation technology. On Linux, the only supported value is `default`. On Windows, acceptable values are `default`, `process` and `hyperv`. Refer to the -[Docker Engine docs](../../reference/cli/docker/container/run.md#isolation) +[Docker Engine docs](https://docs.docker.com/reference/cli/docker/container/run#isolation) for details. ### labels -Add metadata to containers using [Docker labels](../../config/labels-custom-metadata.md). You can use either an array or a dictionary. +Add metadata to containers using [Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either an array or a dictionary. It's recommended that you use reverse-DNS notation to prevent your labels from conflicting with those used by other software. @@ -932,7 +960,7 @@ the alias, or the service name if no alias was specified. Links are not required to enable services to communicate - by default, any service can reach any other service at that service’s name. (See also, the -[Links topic in Networking in Compose](../networking.md#link-containers).) +[Links topic in Networking in Compose](https://docs.docker.com/compose/networking#link-containers).) Links also express dependency between services in the same way as [depends_on](#depends_on), so they determine the order of service startup. @@ -956,7 +984,7 @@ logging: The `driver` name specifies a logging driver for the service's containers, as with the ``--log-driver`` option for docker run -([documented here](../../config/containers/logging/configure.md)). +([documented here](https://docs.docker.com/config/containers/logging/configure)). The default value is json-file. @@ -1282,7 +1310,7 @@ web: Specify the default number of containers to deploy for this service. Whenever you run `docker-compose up`, Compose creates or removes containers to match the specified number. This value can be overridden using the -[`--scale`](../../reference/cli/docker/compose/up.md) +[`--scale`](https://docs.docker.com/reference/cli/docker/compose/up) ```yaml web: @@ -1395,7 +1423,7 @@ userns_mode: "host" ``` Disables the user namespace for this service, if Docker daemon is configured with user namespaces. -See [dockerd](../../engine/security/userns-remap.md#disable-namespace-remapping-for-a-container) for +See [dockerd](https://docs.docker.com/engine/security/userns-remap#disable-namespace-remapping-for-a-container) for more information. ### volumes @@ -1483,7 +1511,7 @@ volumes: > When creating bind mounts, using the long syntax requires the > referenced folder to be created beforehand. Using the short syntax > creates the folder on the fly if it doesn't exist. -> See the [bind mounts documentation](../../storage/bind-mounts.md#differences-between--v-and---mount-behavior) +> See the [bind mounts documentation](https://docs.docker.com/storage/bind-mounts#differences-between--v-and---mount-behavior) > for more information. ### volume\_driver @@ -1504,7 +1532,7 @@ volume_driver: mydriver > entry in the [top-level `volumes` option](#volume-configuration-reference). -See [Docker Volumes](../../storage/volumes.md) and +See [Docker Volumes](https://docs.docker.com/storage/volumes) and [Volume Plugins](/engine/extend/plugins_volume/) for more information. ### volumes_from @@ -1545,7 +1573,7 @@ restart: "unless-stopped" ### cpu_count, cpu_percent, cpu\_shares, cpu\_period, cpu\_quota, cpus, cpuset, domainname, hostname, ipc, mac\_address, mem\_limit, memswap\_limit, mem\_swappiness, mem\_reservation, oom_kill_disable, oom_score_adj, privileged, read\_only, shm\_size, stdin\_open, tty, user, working\_dir Each of these is a single value, analogous to its -[docker run](../../reference/cli/docker/container/run.md#runtime-constraints-on-resources) counterpart. +[docker run](https://docs.docker.com/reference/cli/docker/container/run#runtime-constraints-on-resources) counterpart. > Added in [version 2.2](compose-versioning.md#version-22) file format. > @@ -1623,10 +1651,10 @@ While it is possible to declare [volumes](#volumes) on the fly as part of the service declaration, this section allows you to create named volumes that can be reused across multiple services (without relying on `volumes_from`), and are easily retrieved and inspected using the docker command line or API. -See the [docker volume](../../reference/cli/docker/volume/create.md) +See the [docker volume](https://docs.docker.com/reference/cli/docker/volume/create) subcommand documentation for more information. -See [use volumes](../../storage/volumes.md) and [volume plugins](/engine/extend/plugins_volume/) +See [use volumes](https://docs.docker.com/storage/volumes) and [volume plugins](/engine/extend/plugins_volume/) for general information on volumes. Here's an example of a two-service setup where a database's data directory is @@ -1729,7 +1757,7 @@ volumes: > Added in [version 2.1](compose-versioning.md#version-21) file format. Add metadata to containers using -[Docker labels](../../config/labels-custom-metadata.md). You can use either +[Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either an array or a dictionary. It's recommended that you use reverse-DNS notation to prevent your labels from @@ -1778,7 +1806,7 @@ volumes: The top-level `networks` key lets you specify networks to be created. For a full explanation of Compose's use of Docker networking features, see the -[Networking guide](../networking.md). +[Networking guide](https://docs.docker.com/compose/networking). ### driver @@ -1862,7 +1890,7 @@ you can set this option to `true`. > Added in [version 2.1](compose-versioning.md#version-21) file format. Add metadata to containers using -[Docker labels](../../config/labels-custom-metadata.md). You can use either +[Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either an array or a dictionary. It's recommended that you use reverse-DNS notation to prevent your labels from @@ -1958,10 +1986,151 @@ networks: ## Variable substitution -{{< include "content/compose-var-sub.md" >}} +Your configuration options can contain environment variables. Compose uses the +variable values from the shell environment in which `docker compose` is run. For +example, suppose the shell contains `POSTGRES_VERSION=9.3` and you supply this +configuration: + +```yaml +db: + image: "postgres:${POSTGRES_VERSION}" +``` + +When you run `docker compose up` with this configuration, Compose looks for the +`POSTGRES_VERSION` environment variable in the shell and substitutes its value +in. For this example, Compose resolves the `image` to `postgres:9.3` before +running the configuration. + +If an environment variable is not set, Compose substitutes with an empty +string. In the example above, if `POSTGRES_VERSION` is not set, the value for +the `image` option is `postgres:`. + +You can set default values for environment variables using a +`.env` file, which Compose automatically looks for in +project directory (parent folder of your Compose file). +Values set in the shell environment override those set in the `.env` file. + +> Note when using docker stack deploy +> +> The `.env file` feature only works when you use the `docker compose up` command +> and does not work with `docker stack deploy`. +{ .important } + +Both `$VARIABLE` and `${VARIABLE}` syntax are supported. Additionally when using +the [2.1 file format](compose-versioning.md#version-21), it is possible to +provide inline default values using typical shell syntax: + +- `${VARIABLE:-default}` evaluates to `default` if `VARIABLE` is unset or + empty in the environment. +- `${VARIABLE-default}` evaluates to `default` only if `VARIABLE` is unset + in the environment. + +Similarly, the following syntax allows you to specify mandatory variables: + +- `${VARIABLE:?err}` exits with an error message containing `err` if + `VARIABLE` is unset or empty in the environment. +- `${VARIABLE?err}` exits with an error message containing `err` if + `VARIABLE` is unset in the environment. + +Other extended shell-style features, such as `${VARIABLE/foo/bar}`, are not +supported. + +You can use a `$$` (double-dollar sign) when your configuration needs a literal +dollar sign. This also prevents Compose from interpolating a value, so a `$$` +allows you to refer to environment variables that you don't want processed by +Compose. + +```yaml +web: + build: . + command: "$$VAR_NOT_INTERPOLATED_BY_COMPOSE" +``` + +If you forget and use a single dollar sign (`$`), Compose interprets the value +as an environment variable and warns you: + +```console +The VAR_NOT_INTERPOLATED_BY_COMPOSE is not set. Substituting an empty string. +``` ## Extension fields > Added in [version 2.1](compose-versioning.md#version-21) file format. -{{< include "content/compose-extfields-sub.md" >}} +It is possible to re-use configuration fragments using extension fields. Those +special fields can be of any format as long as they are located at the root of +your Compose file and their name start with the `x-` character sequence. + +> **Note** +> +> Starting with the 3.7 format (for the 3.x series) and 2.4 format +> (for the 2.x series), extension fields are also allowed at the root +> of service, volume, network, config and secret definitions. + +```yaml +version: "{{% param "compose_file_v3" %}}" +x-custom: + items: + - a + - b + options: + max-size: '12m' + name: "custom" +``` + +The contents of those fields are ignored by Compose, but they can be +inserted in your resource definitions using [YAML anchors](https://yaml.org/spec/1.2/spec.html#id2765878). +For example, if you want several of your services to use the same logging +configuration: + +```yaml +logging: + options: + max-size: '12m' + max-file: '5' + driver: json-file +``` + +You may write your Compose file as follows: + +```yaml +version: "{{% param "compose_file_v3" %}}" +x-logging: + &default-logging + options: + max-size: '12m' + max-file: '5' + driver: json-file + +services: + web: + image: myapp/web:latest + logging: *default-logging + db: + image: mysql:latest + logging: *default-logging +``` + +It is also possible to partially override values in extension fields using +the [YAML merge type](https://yaml.org/type/merge.html). For example: + +```yaml +version: "{{% param "compose_file_v3" %}}" +x-volumes: + &default-volume + driver: foobar-storage + +services: + web: + image: myapp/web:latest + volumes: ["vol1", "vol2", "vol3"] +volumes: + vol1: *default-volume + vol2: + << : *default-volume + name: volume02 + vol3: + << : *default-volume + driver: default + name: volume-local +``` diff --git a/docs/Compose file reference (legacy)/version-3.md b/docs/Compose file reference (legacy)/version-3.md new file mode 100644 index 0000000000..d95d3c33ed --- /dev/null +++ b/docs/Compose file reference (legacy)/version-3.md @@ -0,0 +1,2913 @@ + +This page describes version 3 of the Compose file format. + +This is legacy content. The latest Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/) and is implemented by Docker Compose **1.27.0+**. + +## Compose and Docker compatibility matrix + +There are several versions of the Compose file format – 1, 2, 2.x, and 3.x. The +table below is a quick look. For full details on what each version includes and +how to upgrade, see **[About versions and upgrading](compose-versioning.md)**. + +This table shows which Compose file versions support specific Docker releases. + +| **Compose file format** | **Docker Engine release** | +| ------------------- | ------------------ | +| Compose specification | 19.03.0+ | +| 3.8 | 19.03.0+ | +| 3.7 | 18.06.0+ | +| 3.6 | 18.02.0+ | +| 3.5 | 17.12.0+ | +| 3.4 | 17.09.0+ | +| 3.3 | 17.06.0+ | +| 3.2 | 17.04.0+ | +| 3.1 | 1.13.1+ | +| 3.0 | 1.13.0+ | +| 2.4 | 17.12.0+ | +| 2.3 | 17.06.0+ | +| 2.2 | 1.13.0+ | +| 2.1 | 1.12.0+ | +| 2.0 | 1.10.0+ | + +In addition to Compose file format versions shown in the table, the Compose +itself is on a release schedule, as shown in [Compose +releases](https://github.com/docker/compose/releases/), but file format versions +do not necessarily increment with each release. For example, Compose file format +3.0 was first introduced in [Compose release +1.10.0](https://github.com/docker/compose/releases/tag/1.10.0), and versioned +gradually in subsequent releases. + +The latest Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/) and is implemented by Docker Compose **1.27.0+**. + +## Compose file structure and examples + +Here is a sample Compose file from the voting app sample used in the +[Docker for Beginners lab](https://github.com/docker/labs/tree/master/beginner/) +topic on [Deploying an app to a Swarm](https://github.com/docker/labs/blob/master/beginner/chapters/votingapp.md): + + +{{< accordion title="Example Compose file version 3" >}} + +```yml +version: "{{% param "compose_file_v3" %}}" +services: + + redis: + image: redis:alpine + ports: + - "6379" + networks: + - frontend + deploy: + replicas: 2 + update_config: + parallelism: 2 + delay: 10s + restart_policy: + condition: on-failure + + db: + image: postgres:9.4 + volumes: + - db-data:/var/lib/postgresql/data + networks: + - backend + deploy: + placement: + max_replicas_per_node: 1 + constraints: + - "node.role==manager" + + vote: + image: dockersamples/examplevotingapp_vote:before + ports: + - "5000:80" + networks: + - frontend + depends_on: + - redis + deploy: + replicas: 2 + update_config: + parallelism: 2 + restart_policy: + condition: on-failure + + result: + image: dockersamples/examplevotingapp_result:before + ports: + - "5001:80" + networks: + - backend + depends_on: + - db + deploy: + replicas: 1 + update_config: + parallelism: 2 + delay: 10s + restart_policy: + condition: on-failure + + worker: + image: dockersamples/examplevotingapp_worker + networks: + - frontend + - backend + deploy: + mode: replicated + replicas: 1 + labels: [APP=VOTING] + restart_policy: + condition: on-failure + delay: 10s + max_attempts: 3 + window: 120s + placement: + constraints: + - "node.role==manager" + + visualizer: + image: dockersamples/visualizer:stable + ports: + - "8080:8080" + stop_grace_period: 1m30s + volumes: + - "/var/run/docker.sock:/var/run/docker.sock" + deploy: + placement: + constraints: + - "node.role==manager" + +networks: + frontend: + backend: + +volumes: + db-data: +``` +{{< /accordion >}} + +The topics on this reference page are organized alphabetically by top-level key +to reflect the structure of the Compose file itself. Top-level keys that define +a section in the configuration file such as `build`, `deploy`, `depends_on`, +`networks`, and so on, are listed with the options that support them as +sub-topics. This maps to the `: