Question

Puppet in Docker How can I use docker to create a container that has puppet inside and can perform any instruction just like how a Puppet Manifest does

Answer 1

Run the following docker command:

$ docker run --name apply-test puppet/puppet-agent apply -e 'file { "/tmp/adhoc": content => "Written by Puppet" }'

This will pull the puppet/puppet-agent image from Docker Hub and use Puppet to apply a change, namely creating a file in /tmp/adhoc containing the words, “Written by Puppet.”

If you now run a diff on that container, you’ll see what’s changed from the original image. 

In this case, upon running, the container created new folders and added content to them, including the /tmp/adhoc file:

root@node02:~# docker diff apply-test
C /etc
C /etc/puppetlabs
C /etc/puppetlabs/puppet
A /etc/puppetlabs/puppet/ssl
A /etc/puppetlabs/puppet/ssl/certificate_requests
A /etc/puppetlabs/puppet/ssl/certs
A /etc/puppetlabs/puppet/ssl/private
A /etc/puppetlabs/puppet/ssl/private_keys
A /etc/puppetlabs/puppet/ssl/public_keys
...
C /tmp
A /tmp/adhoc

This approach is much faster when compared to the conventional way of creating a separate puppet node.