steps.md

STEPS TO RUN DOCKER CONTAINER

Short description

• Dockerfile: Template to build docker image
• Docker Image: Can be pushed, pulled, tagged to the docker-registry
• Docker Container: Instance of a tagged docker image

STEPS

1) Create Dockerfile

Define base image

FROM ubuntu:16.04

Needed Ports must be exposed

EXPOSE 8555 9051 40332

Define user during execution

USER root

Define working dir

WORKDIR /root

Change form sh to bash

SHELL ["/bin/bash", "-c"]

Define environment variables

ENV BTXPWD "xyz"

Every RUN is a new layer

Example:

cd && \
 rm -rf BitCore && \
 echo '*** Done 4/10 ***'

Change form sh to bash

SHELL ["/bin/bash", "-c"]

Copy files into the docker image (in the same directory as the Dockerfile)

COPY bitcore.conf /tmp

Use of if/for statements in this way

Example:

RUN if [ "$(curl -Is https://bitcore.cc/$BOOTSTRAP | head -n 1 | tr -d '\r\n')" = "HTTP/1.1 200 OK" ] ; then \
 wget https://bitcore.cc/$BOOTSTRAP; \
 tar -xvzf $BOOTSTRAP; \
 rm $BOOTSTRAP; \
 fi

Define the starting point of docker container

Example:

COPY start.sh /root/start.sh
RUN \
 rm -f /var/log/access.log && mkfifo -m 0666 /var/log/access.log && \
 chmod 755 /root/start.sh /usr/local/bin/*
ENV TERM linux
CMD ["/root/start.sh"]

Hints:

• no systemd permission within the docker image => run daemon in foreground
• no ufw within the docker image, but configuration on docker host needed

2) Build docker image

docker build [--build-arg BTXPWD='<bitcore user pwd>'] -t btx-rpc-server .

3) Tag docker image

docker tag btx-rpc-server <repository>/btx-rpc-server

4) Login to hub.docker

docker login -u <repository> -p"<PWD>"

5) Push docker images

docker push <repository>/btx-rpc-server

6) Cleanup docker images

a) Delete all stopped containers (including data-only containers)

docker rm $(docker ps -a -q)

b) Delete all 'untagged/dangling' () images

docker rmi $(docker images -q -f dangling=true)

7) Pull docker image

docker pull <repository>/btx-rpc-server

8) Run docker container

docker run -p 40332:40332 -p 8555:8555 -p 9051:9051 --name btx-rpc-server -e BTXPWD='NEW_BTX_PWD' -v /home/bitcore:/home/bitcore:rw -d <repository>/btx-rpc-server
docker ps

DEBUGGING

A) Debbuging within a container (after start.sh execution)

Please execute "docker run" in 8) before you execute this command:

tail -f /home/bitcore/.bitcore/debug.log
docker ps
docker exec -it btx-rpc-server bash
  # you are inside the btx-rpc-server container
  root@container# supervisorctl status bitcored
  root@container# cat /var/log/supervisor/supervisord.log
  # Change to bitcore user
  root@container# sudo su bitcore
  bitcore@container# cat /home/bitcore/.bitcore/debug.log
  bitcore@container# bitcore-cli getinfo

B) Debbuging within a container during run (skip start.sh execution)

docker run -p 40332:40332 -p 8555:8555 -p 9051:9051 --name btx-rpc-server -e BTXPWD='NEW_BTX_PWD' -v /home/bitcore:/home/bitcore:rw --entrypoint bash <repository>/btx-rpc-server

USE OF VOLUME (FILE SHARING)

If the Dockerfile define the VOLUME you can share files between docker host and docker container.

Example:

VOLUME /var/log

To find out the share directory you need the name of the mounted volume:

docker inspect -f "{{json .Mounts}}" btx-rpc-server | jq .
[
  {
    "Propagation": "",
    "RW": true,
    "Mode": "",
    "Driver": "local",
    "Destination": "/var/log",
    "Source": "/var/lib/docker/volumes/1092068a8200e64d27a1f5971fba1078980ccd20616119474b59af1557332307/_data",
    "Name": "1092068a8200e64d27a1f5971fba1078980ccd20616119474b59af1557332307",
    "Type": "volume"
  }
]

Here is the mapping:

• DOCKERHOST: /var/lib/docker/volumes/1092068a8200e64d27a1f5971fba1078980ccd20616119474b59af1557332307/_data
• DOCKER CONTAINER: /var/log