This page describes how to start Redis and Webdis in Docker Compose, with secure connections between the two.
For this, we'll need:
- Docker Compose (you should have it if you use Docker Desktop)
- Redis version 6 or newer (we'll use a Docker image)
- Webdis version 0.1.18 or newer (also in a Docker image)
- A client certificate and key
- A CA certificate
- The
openssl
command-line tool - Optionally,
curl
for downloading a few files
We'll keep all our files together in a playground
directory:
mkdir playground
cd playground
Let's start by generating the files required to encrypt connections. These instructions are adapted from the Makefile
on this page.
First, the CA cert. Generate a key for it, and then the cert:
openssl genrsa 4096 > ./ca.key
openssl req -new -x509 -nodes -sha256 -key ./ca.key -days 3650 \
-subj "/C=AU/CN=example" -out ./ca.crt
Let's start with a custom OpenSSL config file (change the path from /etc/ssl
if your openssl.cnf
is located elsewhere, e.g. at /etc/pki/tls/openssl.cnf
on Fedora).
cp /etc/ssl/openssl.cnf .
echo >> ./openssl.cnf
echo '[ san_env ]' >> ./openssl.cnf
echo 'subjectAltName = IP:127.0.0.1' >> ./openssl.cnf
If you can't find your openssl.cnf, click here to show a basic file you can use.
Save the following block as openssl.cnf
in your playground
directory:
[ req ]
distinguished_name = req_distinguished_name
attributes = req_attributes
[ req_distinguished_name ]
countryName = Country Name (2 letter code)
countryName_min = 2
countryName_max = 2
stateOrProvinceName = State or Province Name (full name)
localityName = Locality Name (eg, city)
0.organizationName = Organization Name (eg, company)
organizationalUnitName = Organizational Unit Name (eg, section)
commonName = Common Name (eg, fully qualified host name)
commonName_max = 64
emailAddress = Email Address
emailAddress_max = 64
[ req_attributes ]
challengePassword = A challenge password
challengePassword_min = 4
challengePassword_max = 20
[ san_env ]
subjectAltName = IP:127.0.0.1
Then we can create the CSR and key:
export SAN='IP:127.0.0.1'
openssl req -reqexts san_env -extensions san_env -config ./openssl.cnf \
-newkey rsa:4096 -nodes -sha256 -keyout ./redis.key \
-subj "/C=AU/CN=127.0.0.1" -out ./redis.csr
Make sure this command created redis.key
and redis.csr
.
Finally, let's generate the certificate:
openssl x509 -req -sha256 -extfile ./openssl.cnf -extensions san_env \
-days 3650 -in ./redis.csr -CA ./ca.crt -CAkey ./ca.key \
-CAcreateserial -out ./redis.crt
We should now have ca.crt
, redis.key
, and redis.crt
. We'll need these 3 files to configure the encrypted connections between Webdis and Redis. The other files generated by openssl
(redis.csr
and ca.key
) are not needed by Redis or Webdis.
Let's start with the config files needed by Redis and Webdis; we'll keep them all in a local directory that is mounted by the containers.
mkdir config
cp ca.crt redis.key redis.crt ./config
curl -sL -o ./config/webdis.json https://github.com/nicolasff/webdis/raw/0.1.22/webdis.json
curl -sL -o ./config/redis.conf https://github.com/redis/redis/raw/7.0.10/redis.conf
If you don't have curl
, use the two URLs above to fetch webdis.json
and redis.conf
and move them to the config
directory under playground
.
Edit ./config/webdis.json
and set:
"redis_host"
to"redis"
"redis_port"
to6380
"logfile"
to"/dev/stderr"
And add a key named "ssl"
at the same depth as the two keys above (e.g. just under "database": 0
), pointing to:
{
"enabled": true,
"ca_cert_bundle": "/config/ca.crt",
"client_cert": "/config/redis.crt",
"client_key": "/config/redis.key"
},
Click here to see what webdis.json should look like after these changes.
{
"redis_host": "redis",
"redis_port": 6380,
"http_host": "0.0.0.0",
"http_port": 7379,
"threads": 5,
"pool_size": 20,
"daemonize": false,
"websockets": false,
"database": 0,
"ssl": {
"enabled": true,
"ca_cert_bundle": "/config/ca.crt",
"client_cert": "/config/redis.crt",
"client_key": "/config/redis.key"
},
"acl": [
{
"disabled": ["DEBUG"]
},
{
"http_basic_auth": "user:password",
"enabled": ["DEBUG"]
}
],
"verbosity": 4,
"logfile": "/dev/stderr"
}
If you have jq
installed, you can validate that it is valid JSON with:
jq empty ./config/webdis.json && echo 'VALID' || echo 'INVALID'
Then, edit ./config/redis.conf
and uncomment the following configuration options and set their values as listed:
tls-port 6380
(this should initially say# tls-port 6379
, make sure to change the port number)tls-cert-file /config/redis.crt
tls-key-file /config/redis.key
tls-ca-cert-file /config/ca.crt
protected-mode no
Again, make sure to remove any leading #
and spaces from these lines. For example, tls-port
is originally commented out in redis.conf
and looks like this:
# tls-port 6379
Finally, change the line which starts with bind
to:
bind 0.0.0.0
You can also grab redis.conf
from this Gist which contains a Redis 6.2.6 config file with the required changes.
Create a new file named docker-compose.yml
in your playground
directory, with the following contents:
services:
webdis:
image: nicolas/webdis:latest
command: /usr/local/bin/webdis-ssl /config/webdis.json
volumes: # mount volume containing the config files
- ./config:/config
networks:
- secure
depends_on: # make sure Redis starts first, so that Webdis can connect to it without retries
- redis
ports: # allow connections from the Docker host on localhost, port 7379
- "127.0.0.1:7379:7379"
redis:
image: redis:7.0.10
command: /usr/local/bin/redis-server /config/redis.conf
volumes: # mount volume containing the config files
- ./config:/config
networks:
- secure
expose: # make the TLS port from Redis visible to Webdis
- "6380"
networks:
secure:
This configures two services named webdis
and redis
, sharing a common network named secure
. With the expose
property Redis allows connections from Webdis on port 6380. Both containers mount the local config
directory under /config
and start their binaries using the configuration files we've just created and edited. Finally, Webdis also allows binds its (container) port 7379 to the hosts's loopback interface also on port 7379. This will let us run curl
locally to connect to Webdis from the host.
Note: While the Webdis Docker image does bundle a Redis binary, it makes more sense to use multiple containers to demonstrate the use of SSL connections. This bundled Redis service does not run in this example, since we replace the Webdis command with one that only starts Webdis instead of starting Redis and Webdis together in the same container.
From the playground
directory, run:
docker-compose up
You should see both services logging to the console in different colors, with an output like:
Creating playground_redis_1 ... done
Creating playground_webdis_1 ... done
Attaching to playground_redis_1, playground_webdis_1
redis_1 | 1:C 21 Aug 2023 01:42:49.704 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
redis_1 | 1:C 21 Aug 2023 01:42:49.705 # Redis version=7.0.10, bits=64, commit=00000000, modified=0, pid=1, just started
redis_1 | 1:C 21 Aug 2023 01:42:49.705 # Configuration loaded
redis_1 | 1:M 21 Aug 2023 01:42:49.716 * monotonic clock: POSIX clock_gettime
webdis_1 | [1] 21 Aug 01:42:51 I Webdis listening on port 7379
webdis_1 | [1] 21 Aug 01:42:51 I Webdis 0.1.22 up and running
redis_1 | 1:M 21 Aug 2023 01:42:49.717 * Running mode=standalone, port=6379.
redis_1 | 1:M 21 Aug 2023 01:42:49.717 # Server initialized
redis_1 | 1:M 21 Aug 2023 01:42:49.718 * Ready to accept connections
You can now run commands against Webdis by connecting to port 7379 on localhost
, e.g.
$ curl -s http://localhost:7379/ping
{"ping":[true,"PONG"]}
$ curl -s http://localhost:7379/info.txt | grep uptime.in.seconds
uptime_in_seconds:27
Stop the services with ctrl-c and remove the entire Docker Compose stack by running docker-compose rm
from the playground
directory.