Require use of mesh gateways in order for service mesh data plane
traffic to flow between peers.
This also adds plumbing for envoy integration tests involving peers, and
one starter peering test.
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.
Proxies dialing exporting services need to know the SPIFFE ID of
services dialed so that the upstream's SANs can be validated.
This commit attaches the SPIFFE ID to all connect proxies exported over
the peering stream so that they are available to importing clusters.
The data in the SPIFFE ID cannot be re-constructed in peer clusters
because the partition of exported services is overwritten on imports.
The importing peer will need to know what SNI and SPIFFE name
corresponds to each exported service. Additionally it will need to know
at a high level the protocol in use (L4/L7) to generate the appropriate
connection pool and local metrics.
For replicated connect synthetic entities we edit the `Connect{}` part
of a `NodeService` to have a new section:
{
"PeerMeta": {
"SNI": [
"web.default.default.owt.external.183150d5-1033-3672-c426-c29205a576b8.consul"
],
"SpiffeID": [
"spiffe://183150d5-1033-3672-c426-c29205a576b8.consul/ns/default/dc/dc1/svc/web"
],
"Protocol": "tcp"
}
}
This data is then replicated and saved as-is at the importing side. Both
SNI and SpiffeID are slices for now until I can be sure we don't need
them for how mesh gateways will ultimately work.
Treat each exported service as a "discovery chain" and replicate one
synthetic CheckServiceNode for each chain and remote mesh gateway.
The health will be a flattened generated check of the checks for that
mesh gateway node.
By changing to use WatchCtx we will actually block for changes to the peering list. WatchCh creates a goroutine to collect errors from WatchCtx and returns immediately.
The existing behavior wouldn't result in a tight loop because of the rate limiting in the surrounding function, but it would still lead to more work than is necessary.
R.B. Boyer