kube-lego with GKE https://github.com/jetstack/kube-lego/issues/12

canary-ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
 name: canary-ingress

spec:
  tls:
  - hosts:
    - canary.example.com
    secretName: canary-tls
  backend:
    # your default service
    serviceName: default-endpoint
    servicePort: api

  rules:
  - host: canary.example.com
    http:
      paths:
      - path: /.well-known/acme-challenge/
        backend:
          serviceName: kube-lego
          servicePort: 8080

kube-lego-deployment.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: kube-lego
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: kube-lego
    spec:
      containers:
      - name: kube-lego
        image: jetstack/kube-lego:0.0.4
        imagePullPolicy: Always
        ports:
        - containerPort: 8080
        livenessProbe:
          failureThreshold: 10
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 10
          successThreshold: 1
        readinessProbe:
          failureThreshold: 10
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 10

        env:
        - name: LEGO_EMAIL
          valueFrom:
            configMapKeyRef:
              name: kube-lego
              key: lego.email
        - name: LEGO_URL
          valueFrom:
            configMapKeyRef:
              name: kube-lego
              key: lego.url
        - name: LEGO_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace

kube-lego-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: kube-lego
spec:
  ports:
  - port: 8080
    targetPort: 8080
    protocol: TCP
  type: NodePort
  selector:
    app: kube-lego