Ansible Part II

I've had more time to play with Ansible, in the background. A little bit at least. Baby steps.

I use it now to deploy SD-WAN networks, which have different types of KVM-based network elements that need to be configured differently on individual virtual machines.

I enhanced it a bit to deploy virtual-machine based routers (Quagga), as I was building a number of routing scenarios on the same KVM host.

I have made some changes to make Ansible work more to my liking:

1. Every VM gets a management adaptor that connects to a default network.
2. The default network is a NAT network that has its own subnet mask and ip range.
3. I assign each VM an IP on this management network in the hosts file on the KVM host.

The ansible launch-vm script uses the getent package to figure out which IP address the VM has by its name, which is defined in the inventory file.

Because the adaptor type I like to use is Realtek, I had to change guestfish in the launch-vm script to use adaptor name ens3. I also had to change it to use an external DNS Server, because the lack of a DNS server was causing some serious issues with the playbooks not running correctly; especially when they needed to locate a host by name (i.e. to do a yum install).

This ansible has turned out to be very convenient. I can deploy VMs lickety split now, freeing up the time I would normally spend tweaking and configuring individual VM instances.

I'm thinking of writing my own Ansible module for Quagga set up and configuration. That might be a project I get into.

Before I do that, I may enhance the playbooks a bit, adding some "when" clauses and things like that. So far everything I have done has been pretty vanilla.