The HTTP client created by `auth.NewClient` has an idle timeout of
30s and each instance periodically gets cert authorities in
`TeleportProcess.syncRotationStateCycle`. If there has been no
activity when the ticker expires then the request will result in a
brand new connection to Auth to be established. This can cause a
spikes in open file descriptors on the Proxy when there are a large
number of instances connected via a tunnel.
To prevent periodic dialing when retrieving cert authorities the
endpoint has been migrated to the new Trust gRPC service. For now
only the get endpoint has been migrated but the rest of the CRUD
operations for cert authorities should be migrated from the HTTP
api to the gRPC service as well.
* Connection Diagnostics: Postgres Database tester
When adding a new resource using the Web UI we want to allow users to
test connecting to it.
We have two connection testers already:
- for SSH Nodes
- for Kube clusters
This PR adds a third tester: Postgres Database.
Most of the required changes for any Database are already present but
we're focusing on Postgres for now. Other databases will be added as
future PRs.
Testing a Database is similar to the other tests:
- generate certs for the logged in user
- connect to the resource using those certs
When generating the certificate, we inject an ID so that the Database
Service can add Connection Diagnostic traces.
rosstimothy