FRR: Adapt to the changes in FRR 10.x

[mattiaswal]

In FRR 10 they changed how it is supposed to use FRR. Now you can not have multiple configuration files (one for ospfd, one for staticd and so on). They already changed this in 9.1 but it was possible to patch away the new behavior, from 10 it is not possible/desired.

This does not mean that we need to upgrade to 10.x just that it possible.

The 9.1 branch (that we use now) in FRR is more or less abandoned.

This is a rather big job, not desired to be forced to do this because we must upgrade FRR due to bugs/CVEs.

[mattiaswal]

Did some initial tests, looks promising. May work as is, needs more testing. frr-reload.py reload config into mgmtd and then to other daemons
Notes:

• remove frr.conf to get ospfd.conf to work? Can work, we shall see if it respect splitted config files if frr.conf is removed.
• test with watchfrr with new feature in finit (reload)

[troglobit]

Finit reload:script feature still in planning stage, but not far away. Will hopefully find some time the coming weeks to get it done 🧑‍🏭