Deploy Node.js Agent Using Init Containers

An example illustrating how to deploy on Kubernetes a sample application with the Node.js Agent using an init container (a.k.a. sidecar).

The init containers option, available in Kubernetes, is used to run additional containers at application startup. You can use this option to deploy your Seeker Agents without modifying your application images. This is achieved by downloading an Agent package using an init container, and loading it to the application container dynamically.

Save the following code snippet in a file, for example, juiceshop.yml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: juice-shop
  namespace: apps
spec:
  selector:
    matchLabels:
      app: juice-shop
  template:
    metadata:
      labels:
        app: juice-shop
    spec:
      initContainers:
          # Download the Node.js Agent package and extract it to the shared folder /seeker.
        - name: download-agent
          image: busybox:stable
          command:
            - /bin/sh
            - -c
            - |              
              echo "Download Seeker Node.js from: ${SEEKER_SERVER_URL}/rest/api/latest/installers/agents/binaries/NODEJS?flavor=TARGZ"
              wget --no-check-certificate -O /tmp/seeker.tgz "${SEEKER_SERVER_URL}/rest/api/latest/installers/agents/binaries/NODEJS?flavor=TARGZ"
              mkdir -p /seeker
              tar zxvf /tmp/seeker.tgz -C /seeker
              rm -f /tmp/seeker.tgz

          # Set the env variables below to point to your own server and project.
          env:
            - name: SEEKER_SERVER_URL
              value: "https://seeker-server:8443"
            - name: SEEKER_PROJECT_KEY
              value: "juice-shop-k8s"
          volumeMounts:
            - name: seeker-agent
              mountPath: "/seeker"
      containers:
        - name: juice-shop
          image: bkimminich/juice-shop
          ports:
            - containerPort: 3000          
          env:
            - name: SEEKER_SERVER_URL
              value: "https://seeker-server:8443"
            - name: SEEKER_PROJECT_KEY
              value: "juice-shop-k8s"
              # Instruct the Node.js runtime to load the Agent on its start
            - name: NODE_OPTIONS
              value: "-r /seeker/package"
          volumeMounts:
            - name: seeker-agent
              mountPath: "/seeker"
      volumes:
        - name: seeker-agent
          emptyDir: {}
---
apiVersion: v1
kind: Service
metadata:
  name: juice-shop-service
  namespace: apps
spec:
  type: NodePort
  selector:
    app: juice-shop
  ports:
    - name: "http"
      protocol: TCP
      port: 3000
      targetPort: 3000
      nodePort: 31082

Deploy the application:
```
kubectl apply -f juiceshop.yml
```
The application starts with the NODE_OPTIONS variable that instructs the Node.js runtime to load the Agent on its start.