The duo of `makeUpstreamFilterChainForDiscoveryChain` and `makeListenerForDiscoveryChain` were really hard to reason about, and led to concealing a bug in their branching logic. There were several issues here:
- They tried to accomplish too much: determining filter name, cluster name, and whether RDS should be used.
- They embedded logic to handle significantly different kinds of upstream listeners (passthrough, prepared query, typical services, and catch-all)
- They needed to coalesce different data sources (Upstream and CompiledDiscoveryChain)
Rather than handling all of those tasks inside of these functions, this PR pulls out the RDS/clusterName/filterName logic.
This refactor also fixed a bug with the handling of [UpstreamDefaults](https://www.consul.io/docs/connect/config-entries/service-defaults#defaults). These defaults get stored as UpstreamConfig in the proxy snapshot with a DestinationName of "*", since they apply to all upstreams. However, this wildcard destination name must not be used when creating the name of the associated upstream cluster. The coalescing logic in the original functions here was in some situations creating clusters with a `*.` prefix, which is not a valid destination.
Fixes an issue described in #10132, where if two DCs are WAN federated
over mesh gateways, and the gateway in the non-primary DC is terminated
and receives a new IP address (as is commonly the case when running them
on ephemeral compute instances) the primary DC is unable to re-establish
its connection until the agent running on its own gateway is restarted.
This was happening because we always preferred gateways discovered by
the `Internal.ServiceDump` RPC (which would fail because there's no way
to dial the remote DC) over those discovered in the federation state,
which is replicated as long as the primary DC's gateway is reachable.
This will behave the way we handle SNI and SPIFFE IDs, where the default
partition is excluded.
Excluding the default ensures that don't attempt to compare default.dc2
to dc2 in OSS.
This commit updates mesh gateway watches for cross-partitions
communication.
* Mesh gateways are keyed by partition and datacenter.
* Mesh gateways will now watch gateways in partitions that export
services to their partition.
* Mesh gateways in non-default partitions will not have cross-datacenter
watches. They are not involved in traditional WAN federation.
Previously the datacenter of the gateway was the key identifier, now it
is the datacenter and partition.
When dialing services in other partitions or datacenters we now watch
the appropriate partition.
These methods only called a single function. Wrappers like this end up making code harder to read
because it adds extra ways of doing things.
We already have many helper functions for constructing these types, we don't need additional methods.
Previously SAN validation for prepared queries was broken because we
validated against the name, namespace, and datacenter for prepared
queries.
However, prepared queries can target:
- Services with a name that isn't their own
- Services in multiple datacenters
This means that the SpiffeID to validate needs to be based on the
prepared query endpoints, and not the prepared query's upstream
definition.
This commit updates prepared query clusters to account for that.
- The TestNodeService helper created services with the fixed name "web",
and now that name is overridable.
- The discovery chain snapshot didn't have prepared query endpoints so
the endpoints tests were missing data for prepared queries
