In an upcoming change we will need to pass a grpc.ClientConnPool from
BaseDeps into Server. While looking at that change I noticed all of the
existing consulOption fields are already on BaseDeps.
Instead of duplicating the fields, we can create a struct used by
agent/consul, and use that struct in BaseDeps. This allows us to pass
along dependencies without translating them into different
representations.
I also looked at moving all of BaseDeps in agent/consul, however that
created some circular imports. Resolving those cycles wouldn't be too
bad (it was only an error in agent/consul being imported from
cache-types), however this change seems a little better by starting to
introduce some structure to BaseDeps.
This change is also a small step in reducing the scope of Agent.
Also remove some constants that were only used by tests, and move the
relevant comment to where the live configuration is set.
Removed some validation from NewServer and NewClient, as these are not
really runtime errors. They would be code errors, which will cause a
panic anyway, so no reason to handle them specially here.
When calling `GetDatacentersByDistance()` or `GetDatacentersMap()`, an
incorrect condition was used to diplay log message, thus flooding
Consul's logs.
Example of message:
```
[WARN] agent.router: Non-server in server-only area: non_server=myClientNode area=lan
```
This message is only valid for WAN areas, filter to avoid creating
hundreds of logs/s on our clusters, each time someone is calling this
method.
Our logs were flooded by such messages when migrating our Consul servers
from 1.7.7 to 1.8.4.
This will issue fix#8663
Occasionally this test would flake. The flakes were fixed by:
1. Stopping the service and retrying to check on metrics. This way we
also include the active_streams going to 0 in the metric calls.
2. Using a reference to the global Metrics. This way when other tests
have background goroutines that are still shutting down, they won't
emit metrics to the metric instance with the fake Sink. The stats
test can patch the local reference to the global, so the existing
statHandlers will continue to emit to the global, but the stats
test will send all metrics to the replacement.
Load balancing policies are configured in service-resolvers. All Envoy load balancing algorithms are currently supported. Including: least_request, round_robin, random, maglev, and ring_hash.
At the moment hash-based load balancing configuration is not applied at mesh gateways since they cannot decrypt traffic to inspect HTTP attributes like headers.
