integration test: mTLS for opaque TCP traffic

[olix0r]

Write an integration test that ensures that a client proxy records the proper metrics (i.e. reflecting mutual identity, pod metadata) when a client application makes an opaque TCP connection to a meshed server.

We should test at least:

• Kubernetes Service IPs;
• Individual pod IPs.

[krzysztofdrys]

How is this different from the tests already present in test/integration/deep/opaqueports? 🤔 Aren't they doing exactly this?

[mateiidavid]

Yeah I think you're right @krzysztofdrys, this seems to already be covered. We test that client apps have expected metrics. I'll go ahead and close this.

[mateiidavid]

Well, seems that we were wrong :D The opaque ports tests we currently have all check whether an inbound TCP connection has been opened on the server. We can probably do the same for clients to be sure outbound conn metrics are properly recorded. Going to re-open this.