* Introduce a new type `ComputedProxyConfiguration` and add a controller for it. This is needed for two reasons. The first one is that external integrations like kubernetes may need to read the fully computed and sorted proxy configuration per workload. The second reasons is that it makes sidecar-proxy controller logic quite a bit simpler as it no longer needs to do this.
* Generalize workload selection mapper and fix a bug where it would delete IDs from the tree if only one is left after a removal is done.
Convert more of the xRoutes features that were skipped in an earlier PR into ComputedRoutes and make them work:
- DestinationPolicy defaults
- more timeouts
- load balancer policy
- request/response header mutations
- urlrewrite
- GRPCRoute matches
xRoute resource types contain a slice of parentRefs to services that they
manipulate traffic for. All xRoutes that have a parentRef to given Service
will be merged together to generate a ComputedRoutes resource
name-aligned with that Service.
This means that a write of an xRoute with 2 parent ref pointers will cause
at most 2 reconciles for ComputedRoutes.
If that xRoute's list of parentRefs were ever to be reduced, or otherwise
lose an item, that subsequent map event will only emit events for the current
set of refs. The removed ref will not cause the generated ComputedRoutes
related to that service to be re-reconciled to omit the influence of that xRoute.
To combat this, we will store on the ComputedRoutes resource a
BoundResources []*pbresource.Reference field with references to all
resources that were used to influence the generated output.
When the routes controller reconciles, it will use a bimapper to index this
influence, and the dependency mappers for the xRoutes will look
themselves up in that index to discover additional (former) ComputedRoutes
that need to be notified as well.
Iryna Shustava
Eric Haberkorn
R.B. Boyer