How to connect to docker daemon in Bitbucket pipeline

Question

I want to run a docker container in a Bitbucket pipeline. To be more explicit: I want to run a python script which builds a docker image using os.system commands. But I cannot execute any commands as it claims the docker daemon is not running. However, I did not find any way to start it.

Here are the commands I run in that python script and their output:

Every other command of type "docker <dosomething" will fail with the same error message.INFO     Running command 'which docker' in '/opt/atlassian/pipelines/agent/build'
INFO     STDOUT b'/usr/bin/docker
'
INFO     Running command 'docker --version' in '/opt/atlassian/pipelines/agent/build'
INFO     STDOUT b'Docker version 19.03.15, build 99e3ed8
'
INFO     Running command 'systemctl start docker' in '/opt/atlassian/pipelines/agent/build'
INFO     STDERR b'/bin/sh: 1: systemctl: not found
'
INFO     Running command 'sudo systemctl start docker' in '/opt/atlassian/pipelines/agent/build'
INFO     STDERR b'/bin/sh: 1: sudo: not found
'
INFO     Trying to remove old Docker container...
INFO     Running command 'docker container rm test_container' in '/opt/atlassian/pipelines/agent/build'
INFO     STDERR b'Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
'

I am using the Python3.8 docker image. This is the pipeline step:

- step: &test-docker
      name: Build the docker container and run the tests against it
      script:
      - pip install tox
      - docker info
      - tox -e test-docker
      services:
        - docker

Louis_6nx0f3 · Answer

Hi, I have faced the same issues.

Can you explain more about how do you build the docker container while you aren't able to connect docker daemon?

pp_d9hk2d · Answer

Hello Jack, thank you very much for the quick answer!
So if I understood you correctly I would have to install either docker in the python-container or use the this image https://hub.docker.com/r/atlassian/pipelines-docker-daemon and install python in it.
When trying to install docker in the Dockerfile using

RUN apt-get -yqq update && apt-get -yqq install docker.io
VOLUME /var/run/docker.sock

I still got the same error when running the python script ("Cannot connect to the docker daemon...")

When I try to install python in the pipelines-docker-daemon image I get the message that "apt" and "sudo" is not available in that image.

I found out that it would work to build the docker container in the Pipeline defined with the bitbucket-pipeline.yml and to access the webservice that container is running from the python script.

Jack Nolddor [Sweet Bananas] · Answer

Hi and welcome,

Note that if you are using a python docker image ( https://hub.docker.com/_/python/ ). Docker itself isnt installed on that image so you can use python commands within your container but not docker commans as docker daemon isnt present on your container.

You cannot use the docker daemon bitbucket pipelines uses to run your docker image, you need to use the one that comes with your container so you may want to install docker on your container in advance or use another docker container to suit your needs.

Regards