Allow opamp extension to include resource attributes automatically

[jaronoff97]

Description

Introduces a new config struct element IncludeResourceAttributes which when enabled (default is false) copies the set resource attributes from the agent into the non-identifying attributes in the agent description message.

Link to tracking issue

Fixes #37487

Testing

Unit

Documentation

n/a

[atoulme]

LGTM. Maybe this needs a bit of coverage in the README.md file.

[codeboten]

Changes look ok, just one question about the go mod change

[douglascamata]

@jaronoff97 I am trying this PR's changes and it seems that something's wrong and set.Resource.Attributes() is empty for me.

Here's what I am trying:

• I added include_resource_attributes: true inside opamp.agent_description
• I set up the system and env resource detectors.
• I added a the env var OTEL_RESOURCE_ATTRIBUTES=douglas-test-attribute=successful to my Collector's deployment.

The attribute douglas-test-attribute was not present in the agent's non-identifying attributes.

I even added a small log to check if things were okay, but I don't see it in my logs:

	resourceAttrs := make(map[string]string, set.Resource.Attributes().Len())
	set.Resource.Attributes().Range(func(k string, v pcommon.Value) bool {
		set.Logger.Info(fmt.Sprintf("Resource attribute %s: %s", k, v.Str()))
		resourceAttrs[k] = v.Str()
		return true
	})

[jaronoff97]

@douglascamata interesting... i have a test for this exact case here. How did you build the opamp extension for your collector?

[douglascamata]

@jaronoff97 I cloned your branch and built the Collector image from there. Here's a snippet of the configuration of my opamp extension:

      opamp:
        agent_description:
          include_resource_attributes: true
          non_identifying_attributes:
            k8s.node.name: ${env:KUBE_NODE_NAME}
        server:
          http:
            endpoint: ${env:OPAMP_SERVER_URL}
            headers:
              Authorization: Bearer ${env:CORALOGIX_PRIVATE_KEY}
            polling_interval: 2m

I can confirm that I see my custom attribute in my metrics pipeline, where the resource detection processor is used.

[jaronoff97]

oh i see why now, you're using the resource attributes processor which adds resource attributes to the telemetry collected by the collector, but not to the collector itself. You'd need to set the resource in the service telemetry like so:

    service:
      telemetry:
        resource:
          hello: world

[douglascamata]

Ahhh, I see, @jaronoff97. I am personally going after enriching the OpAMP agent attributes with the same data collected by the resource detection processor. I understand now that this is unrelated. 👍

[douglascamata]

Sorry for the confusion.

[jaronoff97]

No problem, as far as your issue goes I believe there's a way to do what you'd like via env vars, but that's a different topic. I believe what you can for that is somethign like this but referencing an environment variable with the ${env:MY_ENV_VAR} syntax.

[douglascamata]

@jaronoff97 I will need a lot more than that. I want also all those cloud metadata attributes from AWS, Azure, etc.

[jaronoff97]

@douglascamata let's continue this discussion in slack, there's some features you should be able to take advantage of. (tag me in the #otel-config-file channel in the CNCF slack)

[evan-bradley]

I don't know what's going on with the go.mod change, but if CI passes, I assume it's good. Overall looks good to me.

[codeboten]

Thanks @jaronoff97

[codeboten]

@jaronoff97 please resolve the conflicts and we can get this merged 👍🏻

[jaronoff97]

@codeboten should be g2g! 🙇

[jaronoff97]

resolve the conflicts, should be good for a merge again! 🙇