configMap_init.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: echo-config
  namespace: default
data:
  text: first

configMap_updated.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: echo-config
  namespace: default
data:
  text: second

daemonSet.yaml

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: http-echo-daemonset
  annotations:
    reloader.stakater.com/auto: "true"
spec:
  selector:
    matchLabels:
      app: http-echo-daemonset
  template:
    metadata:
      labels:
        app: http-echo-daemonset
    spec:
      containers:
        - name: http-echo-daemonset
          image: hashicorp/http-echo
          args:
            - "-text=$(TEXT)"
          ports:
            - containerPort: 80
          env:
            - name: TEXT
              valueFrom:
                configMapKeyRef:
                  name: echo-config
                  key: text

---
kind: Service
apiVersion: v1
metadata:
  name: http-echo-daemonset-service
spec:
  type: NodePort
  selector:
    app: http-echo-daemonset
  ports:
    - port: 5678
      nodePort: 30003

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: http-echo-deployment
  annotations:
    reloader.stakater.com/auto: "true"
spec:
  replicas: 1
  selector:
    matchLabels:
      app: http-echo-deployment
  template:
    metadata:
      labels:
        app: http-echo-deployment
    spec:
      containers:
        - name: http-echo-deployment
          image: hashicorp/http-echo
          args:
            - "-text=$(TEXT)"
          ports:
            - containerPort: 80
          env:
            - name: TEXT
              valueFrom:
                configMapKeyRef:
                  name: echo-config
                  key: text

---
kind: Service
apiVersion: v1
metadata:
  name: http-echo-deployment-service
spec:
  type: NodePort
  selector:
    app: http-echo-deployment
  ports:
    - port: 5678
      nodePort: 30001

statefulSet.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: http-echo-statefulset
  annotations:
    reloader.stakater.com/auto: "true"
spec:
  serviceName: "http-echo-statefulset"
  replicas: 1
  selector:
    matchLabels:
      app: http-echo-statefulset
  template:
    metadata:
      labels:
        app: http-echo-statefulset
    spec:
      containers:
        - name: http-echo-statefulset
          image: hashicorp/http-echo
          args:
            - "-text=$(TEXT)"
          ports:
            - containerPort: 80
          env:
            - name: TEXT
              valueFrom:
                configMapKeyRef:
                  name: echo-config
                  key: text

---
kind: Service
apiVersion: v1
metadata:
  name: http-echo-statefulset-service
spec:
  type: NodePort
  selector:
    app: http-echo-statefulset
  ports:
    - port: 5678
      nodePort: 30002

test_reloader_kubernetes_1.16.sh

kubectl apply -f https://raw.githubusercontent.com/stakater/Reloader/master/deployments/kubernetes/reloader.yaml
kubectl apply -f configMap_init.yaml
kubectl apply -f daemonSet.yaml
kubectl apply -f deployment.yaml
kubectl apply -f statefulSet.yaml

# Check value read from pods
curl -L http://192.168.99.100:30001
curl -L http://192.168.99.100:30002
curl -L http://192.168.99.100:30003
# Should display 'first'

# To trigger a reload
kubectl apply -f configMap_updated.yaml

# Check value read from pods
curl -L http://192.168.99.100:30001
curl -L http://192.168.99.100:30002
curl -L http://192.168.99.100:30003
# Should display 'second'