How can I run two commands in CMD or ENTRYPOINT in Dockerfile

Question

In the Dockerfile builder, ENTRYPOINT and CMD run in one time by using /bin/sh -c in back.

Are there any simple solution to run two command inside without extra script

In my case, I want to setup docker in docker in jenkins slave node, so I pass the docker.sock into container, and I want to change the permission to be executed by normal user, so it shall be done before sshd command.

The normal is like jenkins, which will be login into container via ssh command.

$ docker run -d -v /var/run/docker.sock:/docker.sock larrycai/jenkins-slave

In larrycai/jenkins-slave Dockerfile, I hope to run

CMD chmod o+rw /docker.sock && /usr/sbin/sshd -D

Currently jenkins is given sudo permission, see larrycai/jenkins-slave

Answer 1

I run docker in docker in jenkins slave:

First: my slave know run docker.

Second: I prepare one docker image who knows run docker in docker. See one fragment of dockerfile

RUN echo 'deb [trusted=yes] http://myrepo:3142/get.docker.io/ubuntu docker main' > /etc/apt/sources.list.d/docker.list
RUN apt-get update -qq
RUN apt-get install -qqy iptables ca-certificates lxc apt-transport-https lxc-docker
ADD src/wrapdocker /usr/local/bin/wrapdocker
RUN chmod +x /usr/local/bin/wrapdocker
VOLUME /var/lib/docker

Third: The jenkins job running in this slave contain one .sh file with a set of command to run over app code like:

export RAILS_ENV=test
# Bundle install
bundle install

# spec_no_rails
bundle exec rspec spec_no_rails -I spec_no_rails
bundle exec rake db:migrate:reset
bundle exec rake db:test:prepare
etc...

Fourth: one run shell step job with something like this

docker run --privileged -v /etc/localtime:/etc/localtime:ro -v `pwd`:/code myimagewhorundockerindocker /bin/bash -xec 'cd /code && ./myfile.sh'

--privileged necessary for run docker in docker

-v /etc/localtime:/etc/localtime:ro for synchronize host clock vs container clock

-v pwd:/code for share jenkins workspace (app-code) previously cloned from VCS with /code inside container

note: If you have service dependencies you can use fig with similar strategy.