Readme.md

Azure Application Insights in Kubernetes for Java

This gist describes how to add Kubernetes customDismensions to the Java agent for Application Insights.

It's supplying the same customDimensions that are provided by the asp.net 6+ instrumentiation, except that not all of those dimensions are available using the Kubernetes Downward API

How it Works

The supplied app-insights-java.yaml patch file configures customDimensions for the app insights agent using the APPLICATIONINSIGHTS_CONFIGURATION_CONTENT env var. This will override your applicationinsights.json configuration file if you were using one.

The example kustomization.yaml applies the patch to all deployments with the instrumentation.opentelemetry.io/inject-java: "true" annotation. This is the same annotation that is used by the Open Telemetry Kuberentes Operator. However, that operator selects pods with the annotation.

NOTE

Only the first container in each pod will have the configuration injected. If you want to inject into other pods, then you will need to replace the 0 in the path:s with the container index.

app-insights-java.yaml

- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: NODE_NAME
    valueFrom:
      fieldRef:
        fieldPath: spec.nodeName
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: POD_NAME
    valueFrom:
      fieldRef:
        fieldPath: metadata.name
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: POD_NAMESPACE
    valueFrom:
      fieldRef:
        fieldPath: metadata.namespace
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: POD_ID
    valueFrom:
      fieldRef:
        fieldPath: metadata.uid
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: POD_SERVICE_ACCOUNT
    valueFrom:
      fieldRef:
        fieldPath: spec.serviceAccountName
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: POD_LABELS_APP
    valueFrom:
      fieldRef:
        fieldPath: metadata.labels['app']
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: APPLICATIONINSIGHTS_CONFIGURATION_CONTENT
    value: |
      {
        "customDimensions": {
          "Kubernetes.Container.Name": "${POD_LABELS_APP}",
          "Kubernetes.Deployment.Name": "${POD_LABELS_APP}",
          "Kubernetes.Node.Name": "${NODE_NAME}",
          "Kubernetes.Pod.ID": "${POD_ID}",
          "Kubernetes.Pod.Labels": "app=${POD_LABELS_APP}",
          "Kubernetes.Pod.Name": "${POD_NAME}",
          "Kubernetes.Pod.Namespace": "${POD_NAMESPACE}",
          "Kubernetes.Pod.ServiceAccount": "${POD_SERVICE_ACCOUNT}"
        }
      }

## Use these to see all the available labels and annotations
# - op: add
#   path: /spec/template/spec/containers/0/volumeMounts/-
#   value:
#     name: podinfo
#     mountPath: /etc/podinfo
# - op: add
#   path: /spec/template/spec/volumes/-
#   value:
#     name: podinfo
#     downwardAPI:
#       items:
#         - path: "labels"
#           fieldRef:
#             fieldPath: metadata.labels
#         - path: "annotations"
#           fieldRef:
#             fieldPath: metadata.annotations

kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - my-app.yaml
patches:
  - path: app-insights-java.yaml
    target:
      kind: Deployment
      annotationSelector: instrumentation.opentelemetry.io/inject-java=true

my-app.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
  labels:
    app: my-app
  annotations:
    instrumentation.opentelemetry.io/inject-java: "true"