Comparing our progress with football, we have reached the half way line in the field, and we have scored quite a few goals in the game already. I hope you have had your half time team talk, refueled yourself with cold drinks, and have stretched your muscles for the second half action that is about to begin.

Until now, we have learned how to set up the development environment where we can build new Puppet modules easily and test them in the cluster that consists of multiple nodes. The environment was fully configured with Puppet, and in the process, we got to experiment with various building blocks such as built-in resource types, facts, variables, parameterized classes, and defined types.

But I believe that not all of this has been easy or problem free, not for me at least. For example, when the cluster members (hosts) sometimes get new IP address from the DHCP server and we then have to adjust the IP configuration in the manifest files to enable...