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.
For initial cluster peering TProxy support we consider all imported services of a partition to be potential upstreams.
We leverage the VirtualIP table because it stores plain service names (e.g. "api", not "api-sidecar-proxy").
Mesh gateways will now enable tcp connections with SNI names including peering information so that those connections may be proxied.
Note: this does not change the callers to use these mesh gateways.
Envoy's SPIFFE certificate validation extension allows for us to
validate against different root certificates depending on the trust
domain of the dialing proxy.
If there are any trust bundles from peers in the config snapshot then we
use the SPIFFE validator as the validation context, rather than the
usual TrustedCA.
The injected validation config includes the local root certificates as
well.
For mTLS to work between two proxies in peered clusters with different root CAs,
proxies need to configure their outbound listener to use different root certificates
for validation.
Up until peering was introduced proxies would only ever use one set of root certificates
to validate all mesh traffic, both inbound and outbound. Now an upstream proxy
may have a leaf certificate signed by a CA that's different from the dialing proxy's.
This PR makes changes to proxycfg and xds so that the upstream TLS validation
uses different root certificates depending on which cluster is being dialed.
This is the OSS portion of enterprise PRs 1904, 1905, 1906, 1907, 1949,
and 1971.
It replaces the proxycfg manager's direct dependency on the agent cache
with interfaces that will be implemented differently when serving xDS
sessions from a Consul server.