Add OpenTelemetry in Azure ContainerApps

[agoncal]

ATM OpenTelemetry is still not supported in ACA.

• Feature Request: support third-party monitoring solutions microsoft/azure-container-apps#289
• https://github.com/ezYakaEagle442/aca-java-petclinic-mic-srv/blob/main/iac/bicep/aca/aca.bicep#L223
• https://github.com/ezYakaEagle442/aca-java-petclinic-mic-srv/blob/main/docker/petclinic-customers-service/Dockerfile#L17
• Feature Request: Application Insights / Distributed tracing support microsoft/azure-container-apps#290
• https://docs.microsoft.com/en-us/azure/azure-monitor/app/java-in-process-agent#point-the-jvm-to-the-jar-file
• Feature Request: Expose OpenTelemetry Collector configuration microsoft/azure-container-apps#208 (comment)

[Depechie]

For reference: https://www.honeycomb.io/blog/opentelemetry-collector-azure-container-apps this should work.

[edeandrea]

That seems like a lot of extra work just to inject some configuration into a container.

1. It forces you to use Azure storage
2. It forces you to use/manage yaml configs of your container apps

On Kubernetes, I could just store the otel config yaml in a ConfigMap and then mount it to the container. Why does that have to be so complicated on container apps?