Cluster network and service network made customizable

[palonsoro]

It would be nice to be able to customize cluster networks and service network at install time.

[palonsoro]

I have marked this as draft because it is pending on some testing on my side.

[palonsoro]

I forgot about this thing for a while. During this time, variables to customize service network and cluster network were added to kcli. However, the one about customizing cluster network allows a single clusternetwork, not multiple CIDRs, so changing the scope of this PR to bring that feature.

I just hope to not leave this undone for much longer :-)

[palonsoro]

I'd prefer to have https://github.com/karmab/kcli/issues/384 with a definitive fix and rebase on it.

[palonsoro]

Finally!!!!

I could finally make some time to review this. It works as expected in IPv4, IPv6 and dualstack.

The idea is:

• Service network is still intended to be customized via service_network_ipv4 and service_network_ipv6 only, because only one per kind is possible
• Single pod network CIDR with default hostsubnet length can still be specified via cluster_network_ipv4 and cluster_network_ipv6 variables.
• If a "richer" configuration is desired (more than one cluster network for a single IP family, different hostsubnet length...), the whole cluster_network variable may be specified. User is responsible of following the correct format and of providing at least one cluster network per IP family.

[karmab]

addressed in https://github.com/karmab/kcli/commit/afef690e316ffc1554e77b0491cd38c5da5368c8