npezzotti / hello-world-spring-boot

Example of Datadog APM setup in Kubernetes

Kubernetes tracing exercise

Prerequisites

Install the following tools:

• Minikube: https://minikube.sigs.k8s.io/docs/start/
• kubectl: https://kubernetes.io/docs/tasks/tools/
• Helm: https://helm.sh/docs/intro/install/

Steps

• Clone respositry:

git clone [e-mail]:npezzotti/hello-world-spring-boot.git && cd hello-world-spring-boot

• Start Minikube

minikube start

• Point your terminal’s docker-cli to the Docker Engine inside minikube

eval $(minikube docker-env)

• Build image:

docker build -t hello-world-spring-boot .

• Deploy to Minikube:

kubectl apply -f kubernetes/

• Run the following command to open the app in your browser:

minikube service hello-world-spring-boot

• Delete deployment

kubectl delete -f kubernetes/

Set up APM

• Add the Java tracer
  • In the Dockerfile, add the following line directly under RUN apk add --no-cache wget

  RUN wget -O dd-java-agent.jar https://dtdg.co/latest-java-tracer
  

  • Edit the ENTRYPOINT command to start the app with the Java tracer:

  ENTRYPOINT ["java", "-javaagent:dd-java-agent.jar", "-jar", "target/helloWorld-0.0.1-SNAPSHOT.jar"]
  

• Rebuild the image:

docker build -t hello-world-spring-boot .

• Configure the application deployment file (kubernetes/hello-world-spring-boot-deploy.yaml) with the following additions:
  • TCP

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      labels:
        ...
        tags.datadoghq.com/env: "test"
        tags.datadoghq.com/service: "hello-world-spring-boot"
        tags.datadoghq.com/version: "1.0"
    spec:
      ...
      template:
        metadata:
          labels:
            ...
            tags.datadoghq.com/env: "test"
            tags.datadoghq.com/service: "hello-world-spring-boot"
            tags.datadoghq.com/version: "1.0"
        spec:
          ...
          containers:
            ...
            env:
            - name: DD_AGENT_HOST
              valueFrom:
                fieldRef:
                  fieldPath: status.hostIP
            - name: DD_ENV
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['tags.datadoghq.com/env']
            - name: DD_SERVICE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['tags.datadoghq.com/service']
            - name: DD_VERSION
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['tags.datadoghq.com/version']
    

  • UDS

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      labels:
        ...
        tags.datadoghq.com/env: "test"
        tags.datadoghq.com/service: "hello-world-spring-boot"
        tags.datadoghq.com/version: "1.0"
    spec:
      ...
      template:
        metadata:
          labels:
            ...
            tags.datadoghq.com/env: "test"
            tags.datadoghq.com/service: "hello-world-spring-boot"
            tags.datadoghq.com/version: "1.0"
        spec:
          ...
          volumes:
            - hostPath:
                path: /var/run/datadog/
              name: apmsocketpath
          containers:
            ...
            volumeMounts:
              - name: apmsocketpath
                mountPath: /var/run/datadog
            env:
            - name: DD_ENV
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['tags.datadoghq.com/env']
            - name: DD_SERVICE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['tags.datadoghq.com/service']
            - name: DD_VERSION
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['tags.datadoghq.com/version']
    

• Run the following command to install the Datadog Helm Chart

helm repo add datadog https://helm.datadoghq.com
helm repo update

• Run the following command to pull the Datadog values and save it to a file:

helm show values datadog/datadog > values.yaml

• Edit the values.yaml to set the following:
  • TCP:

    datadog:
      apm:
        portEnabled: true
      dogstatsd:
        useHostPort: true
      kubelet:
        tlsVerify: false
    

  • UDS: no changes required
• Install the Datadog release:

helm install datadog -f values.yaml  --set datadog.apiKey=<DATADOG_API_KEY> datadog/datadog --set targetSystem=linux

• Redeploy Spring Boot

kubectl apply -f kubernetes/

• Open the application in browser:

 minikube service hello-world-spring-boot 

• Check Datadog account for traces (query for env:test service:hello-world-spring-boot)

Clean Up

minikube delete