Puppet and Docker docker exec doesn t start puppet container automatically

Question

 I need to run the command docker exec to start the container and run the following commands to get it started and create the ca certificates in its ssl directory:

puppet master --verbose 
service puppetmaster start
chkconfig puppetmaster on

Here's the dockerfile for a puppet container for a certificate authority.This doesn't start automatically,

FROM centos:6
RUN yum update -y
RUN rpm -ivh http://yum.puppetlabs.com/puppetlabs-release-el-6.noarch.rpm
RUN yum install -y ruby puppet-server  
ADD puppet.conf /etc/puppet/puppet.conf

VOLUME ["/var/lib/puppet/ssl/"]
EXPOSE 9140

#NOTHING BELOW THIS COMMENT RUNS
RUN puppet master --verbose 

CMD service puppetmaster start
CMD chkconfig puppetmaster on
CMD []

The container can be started using the run(note that I named the image ca-puppet):

docker run -d -p 9140:9140 -it --name ca-puppet \
-v /puppet-host/ssl:/var/lib/puppet/ssl \
ca-puppet bash

Answer 1

There can only be one CMD instruction in a Dockerfile. If you list more than one CMD then only the last CMD will take effect.

If the user specifies arguments to docker run then they will override the default specified in CMD.

Try not daemonizing puppet and start it as the default container command via something like:

CMD puppet master --verbose --no-daemonize

And use the Docker host to manage it (via restart policy, etc.).