feat(MeshTrace): add support for opentelemetry trace backend

[frzifus]

This pr adds support to export traces in otel format. it is still in an early and experimental stage. ^^

Closes #3690

Checklist prior to review

• Link to docs PR or issue -- OpenTelemetry support for tracing #3690
• Link to UI issue or PR -- None
• Is the issue worked on linked? --
• The PR does not hardcode values that might break projects that depend on kuma (e.g. "kumahq" as a image registry) --
• The PR will work for both Linux and Windows, system specific functions like syscall.Mkfifo have equivalent implementation on the other OS --
• Unit Tests --
• E2E Tests --
• Manual Universal Tests --
• Manual Kubernetes Tests --
• Do you need to update UPGRADE.md? -- No
• Does it need to be backported according to the backporting policy? -- No
• Do you need to explicitly set a > Changelog: entry here or add a ci/ label to run fewer/more tests?

---

See: envoyproxy/envoy#9958 (comment)

[mmorel-35]

Hi @frzifus ,
Have you considered this reference to define mesh_proto.OTLPTracingBackendConfig

[frzifus]

Have you considered this reference to define mesh_proto.OTLPTracingBackendConfig

What are the settings that come to your mind / you did like to see? Until here I just went for a simple test. ^^

[mmorel-35]

What are the settings that come to your mind / you did like to see?

I’d like to see this for example :

conf:
  compression: gzip
  endpoint: otelcol2:55690
  headers:
    test1: "value1"
  keepalive:
    timeout: 20s
  tls:
    insecure: false
    ca_file: ca.pem
    cert_file: cert.pem
    key_file: key.pem
    insecure_skip_verify: false
    min_version: "1.2"
    max_version: "1.3"

[frzifus]

I’d like to see this for example :

But these are the internal opentelemetry grpc client settings. If I got it right, we can only use the envoy gRPC settings.

[mmorel-35]

That is the opentelemetry exporter grpc client specification, right. This is the protobuf part. Then it needs to be translated into envoy configuration, if I understood it right

[frzifus]

This is not a specification. It is simply a grpc client implementation that is used in the opentelemetry collector {exporter, extensions, ...}. Only these settings are available to us.

[frzifus]

hm.. while working on an e2e test, I noticed that the Jaeger deployment provided by kumactl does not expose otlp.
Should we put this into this pr too. Or do it in a folllow-up? Iam a bit scared that its gets bigger and bigger until it leads to conflicts. ^^
wdyt?

[mmorel-35]

I have found this documentation from Opentelemetry . Have you seen it ?
This part seems to be absent in the actual configuration, shall it be added too ?

      lb_policy: ROUND_ROBIN
      typed_extension_protocol_options:
        envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
          "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
          explicit_http_config:
            http2_protocol_options: {}

Also , there is no timeout defined for the grpc_service

[frzifus]

I have found this documentation from Opentelemetry . Have you seen it ?
This part seems to be absent in the actual configuration, shall it be added too ?

Yes, while adding the endpoint. But tbh I would prefer to continue and add things afterwards step by step.

[mmorel-35]

I would prefer to continue and add things afterwards step by step.

Ok ! That’s alright for me :) !

[michaelbeaumont]

Suggested change

	Endpoint string `json:"endpoint"`
	// +kubebuilder:validation:MinLength=1
	Endpoint string `json:"endpoint"`

[slonka]

@michaelbeaumont - is there any reason it's not called Url to be consistent with other backends? (zipkin, datadog)

[mmorel-35]

Would it be due to the absence of protocol in that field, which is defined for Zipkin and Datadog?

[michaelbeaumont]

LGTM thanks!

[frzifus]

Thanks for guidance @michaelbeaumont !

[slonka]

@michaelbeaumont - is there any reason it's not called Url to be consistent with other backends? (zipkin, datadog)

[slonka]

as mentioned in the previous comment if it was a url then we could simply do:

url.Port()