Added option `prefix_route_link_local` to dhcpy6d-clients.conf

[FelixJacobi]

This is a follow-up to #38 and #39. This changed the default behavior of calling hooks for prefix. It was reasonable, but sometimes you are required explicitly to use the link-local address, e.g. when the client receives more than one address.

To allow everyone to set the required behavior, this adds a prefix_route_link_local in dhcpy6d-clients.conf.

TODO:

• Update doc
• Test changes! (therefore a draft yet)
• @HenriWahl What about changes to configuration database scheme? Is that fine, or should we avoid that?

[HenriWahl]

Looks interesting.

Changing the database scheme for the client config is challenging, because the config database might as well be a view from an external source and thus not as fully under control of dhcpy6d as the leases storage. I know of at least one setup working this way.

A solution may be to provide a dhcpy6d config option, which version of client config should be used and so use different database queries according to the desired version. Lets name the current scheme version 1, your proposed version 2 and lets see what other versions may come in the future?

[FelixJacobi]

Hi @HenriWahl,

Back here again ^^ . I extended the MR (untested yet, just a draft to figure out a proper concept) with a store schema version. WDYT about it?

[FelixJacobi]

Hi @HenriWahl,

in the meantime, I have tested the changes extensively in production. How should we proceed here?