Bring auto-instrumentation to OpenTelemetry K8s Operator

[svrnm]

Is your feature request related to a problem?

With auto instrumentation for PHP being a thing, there is an opportunity to bring it to applications running in K8s clusters via the otel k8s operator automatically.

Describe the solution you'd like
Similar to other languages it would be great to be able to turn on injection of auto instrumentation for PHP, e.g. create an Instrumentation resource that configures the auto instrumentation (copied from python):

apiVersion: opentelemetry.io/v1alpha1
kind: Instrumentation
metadata:
  name: demo-instrumentation
spec:
  exporter:
    endpoint: http://demo-collector:4318
  propagators:
    - tracecontext
    - baggage
  python:
    env:
      - name: OTEL_PHP_...
        value: ...

and add an annotation to deployments:

instrumentation.opentelemetry.io/inject-php: "true"

This would require the creation of an init container, similar to the existing ones:

https://github.com/open-telemetry/opentelemetry-operator/tree/main/autoinstrumentation

and a instrumentationphp.go at

https://github.com/open-telemetry/opentelemetry-operator/tree/main/pkg/instrumentation

cc @open-telemetry/operator-approvers

Additional context
Existing injection for other languages: https://opentelemetry.io/docs/k8s-operator/automatic/

[frzifus]

Sounds like a great idea. :) Do you want to move this issue to the Operator repo?

[svrnm]

I raised it here because @bobstrecansky asked me so the PHP SIG can investigate & prioritize. Maybe both repos should have one issue and we link them?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed because it has not had recent activity, but it can be reopened. Thank you for your contributions.

[cedricziel]

I see value in injecting the extension, do you also want to inject the instrumentation code?

[svrnm]

I see value in injecting the extension, do you also want to inject the instrumentation code?

What ever makes an application emit telemetry automatically, so yes, if it is possible to inject that as well safely (e.g. Node.js is doing it that way)