2.webapp-replicaset.yaml

# Replicaset definition for the webapp deployed in 1.webapp-pod.yaml
# Replicasets ensure the number of pods are always alive
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: webapp
  namespace: demo
  labels:
    app: demo
    tier: frontend
spec:
  replicas: 3 # Number of replicas we would need to be always available.
  selector: # Below configuration identifies and controls the pods to be created
    matchLabels:
      tier: frontend
  template: # Pod definition template
    metadata: # The labels for the pods to be created, this should contain all the "selector.matchLabels" labels and can have more
      labels:
        tier: frontend
    spec: # Same definition as 1.webapp-pod.yaml
      containers:
        - name: webapp
          image: pratapgowda/demo-webapp:1.0
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 8080
          volumeMounts:
            - name: workdir
              mountPath: /usr/share/webapp/html
          resources:
            limits:
              cpu: "500m"
              memory: 1G
            requests:
              cpu: "25m"
              memory: 100Mi
          livenessProbe:
            httpGet:
              path: /health
              port: 8080
            initialDelaySeconds: 3
            periodSeconds: 3
          readinessProbe:
            httpGet:
              path: /health
              port: 8080
            initialDelaySeconds: 3
            periodSeconds: 3
        - name: sidecar
          image: busybox
          imagePullPolicy: IfNotPresent
          resources:
            limits:
              cpu: "500m"
              memory: 1G
            requests:
              cpu: "25m"
              memory: 100Mi
          command: 
            - sleep
            - "6000"
      # These containers are run during pod initialization
      initContainers:
        - name: initializer
          image: pratapgowda/demo-initializer
          imagePullPolicy: IfNotPresent
          env:
            - name: WAIT_IN_SECS
              value: "1"
          volumeMounts:
            - name: workdir
              mountPath: "/work-dir"
      dnsPolicy: Default
      volumes:
        - name: workdir
          emptyDir: {}