I still do not know why i like Puppet so much, But i always loves to play around with it. It’s a very powerful tool for the system admins. I’ve never tried chef before, but i’m very happy with puppet. Thanks to Luke and PuppetLabs for designing such a good tool. My colleague sarguru is working on a newer release of our deepOfix Mail Server, which will be using puppet for config management. In this blog i will explain hot setup Puppet in “StandAlone” as well as in ” Server-Client” mode.
Puppet Master
We can install puppet from the APT. For testing i’m not going to daemonize my puppet master, i will be installing the two basic packages.
“apt-get install puppet puppet-common”
Now, if you have already installed the puppet and if the old ssl certificates are still existing, it can be removed using the below command.
“puppet cert clean –all”
If you are not running a dns server, enusre you have proper FQDN entries in the “/etc/hosts” for server and clients,if any. Now we can start the puppet master. It’s always better to use the debug mode during testing.
“puppet masterc –debug –no-daemonize”
This will start the puppet daemon, and will automatically create a self signed certificate for the puppet master.
StandAloneMode
Now we have puppet master running on the machine. In the StandAloneMode, we can create a “*.pp” file with all the resources and we can invoke puppet to apply the resources locally.
“puppet apply *.pp –debug”
This will the the resource which we mentioned in our puppet policy file.
If a module has to be applied, we have to mention the module path as well as the module that we are gonna apply.
“puppet apply –debug –modulepath=/etc/puppet/modules -e “include modulename””
Note:- Puppet has a very good feature, where we can simulate the changes without actually applying the resources. For that we have to use one option “–noop” (no operation) while executing the puppet apply. This is very helpful for us to simulate the results and see if the resources are being properly.
“”puppet apply –debug –modulepath=/etc/puppet/modules -e “include modulename” –noop”
Client-Server Model
So now we have puppet master running on one machine. On the client machine, similarly install “puppet and puppet-common” packages from APT. Ensure that that the machine can resolve the FQDN of the Puppet Master.
Now run the puppet agent.
“puppet agent –debug –no-daemonize”
If it throws any Name server error, then we can mention the server manually,
“puppet agent –server fqdnofmaster –debug –no-daemonize”
So now on the terminal where we are running the puppet master, we can see a certificate request from the client.
We can also see the csr by running the following command on the puppet master.
“puppet cert list”
We can certify the csr by running,
“puppet cert sign fqdnofclient”
Now we can run the puppet agent again to check whether the agent successfully talk with the the master.
In the client-server model, we need to specify the modules which are going to apply on specific nodes and for default nodes if any. These things are specified in “/etc/puppet/manifests/sites.pp”. Here we will mention the node and the modules to be applied.
Syntax is ,
node ‘node name in fqdn’ {
include modulename
. . . . . .
}
Now when we run the puppet agent,appropriate modules will be installed to the clients as per the site.pp file. We can always verify the syntax of the puppet policy file using “puppet parser validate *.pp”.
beingasysadmin 