This is the OSS portion of enterprise PR 2249.
This PR introduces an implementation of the proxycfg.Health interface based on a
local materialized view of the health events.
It reuses the view and request machinery from agent/rpcclient/health, which made
it super straightforward.
This is the OSS portion of enterprise PR 2056.
This commit provides server-local implementations of the proxycfg.ConfigEntry
and proxycfg.ConfigEntryList interfaces, that source data from streaming events.
It makes use of the LocalMaterializer type introduced for peering replication,
adding the necessary support for authorization.
It also adds support for "wildcard" subscriptions (within a topic) to the event
publisher, as this is needed to fetch service-resolvers for all services when
configuring mesh gateways.
Currently, events will be emitted for just the ingress-gateway, service-resolver,
and mesh config entry types, as these are the only entries required by proxycfg
— the events will be emitted on topics named IngressGateway, ServiceResolver,
and MeshConfig topics respectively.
Though these events will only be consumed "locally" for now, they can also be
consumed via the gRPC endpoint (confirmed using grpcurl) so using them from
client agents should be a case of swapping the LocalMaterializer for an
RPCMaterializer.
The primary bug here is in the streaming subsystem that makes the overall v1/health/service/:service request behave incorrectly when servicing a blocking request with a filter provided.
There is a secondary non-streaming bug being fixed here that is much less obvious related to when to update the `reply` variable in a `blockingQuery` evaluation. It is unlikely that it is triggerable in practical environments and I could not actually get the bug to manifest, but I fixed it anyway while investigating the original issue.
Simple reproduction (streaming):
1. Register a service with a tag.
curl -sL --request PUT 'http://localhost:8500/v1/agent/service/register' \
--header 'Content-Type: application/json' \
--data-raw '{ "ID": "ID1", "Name": "test", "Tags":[ "a" ], "EnableTagOverride": true }'
2. Do an initial filter query that matches on the tag.
curl -sLi --get 'http://localhost:8500/v1/health/service/test' --data-urlencode 'filter=a in Service.Tags'
3. Note you get one result. Use the `X-Consul-Index` header to establish
a blocking query in another terminal, this should not return yet.
curl -sLi --get 'http://localhost:8500/v1/health/service/test?index=$INDEX' --data-urlencode 'filter=a in Service.Tags'
4. Re-register that service with a different tag.
curl -sL --request PUT 'http://localhost:8500/v1/agent/service/register' \
--header 'Content-Type: application/json' \
--data-raw '{ "ID": "ID1", "Name": "test", "Tags":[ "b" ], "EnableTagOverride": true }'
5. Your blocking query from (3) should return with a header
`X-Consul-Query-Backend: streaming` and empty results if it works
correctly `[]`.
Attempts to reproduce with non-streaming failed (where you add `&near=_agent` to the read queries and ensure `X-Consul-Query-Backend: blocking-query` shows up in the results).
