How can I combine the load balancers in Kubernetes?

Question

I have the following Kubernetes YAML for my cluster of HTTP/REST services, is there a way I can expose the identity, users and actions services through the same load balancer?

With the config below it creates 4 separate elastic load balancers in AWS when I think 1 is enough. I tried setting Kibana to NodePort so I could access it externally but I couldn't access it so I set the type to LoadBalancer.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: identity-service
  labels:
    app: identity-service
spec:
  replicas: 1
  selector:
    matchLabels:
      app: identity-service
  template:
    metadata:
      labels:
        app: identity-service
    spec:
      containers:
        - name: identity-service
          image: org_name/identity_service
          imagePullPolicy: Always
          ports:
            - containerPort: 5000
          env:
            - name: CONNECTION_STRING
              value: "..."
      imagePullSecrets:
        - name: docker-hub
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: users-service
  labels:
    app: users-service
spec:
  replicas: 1
  selector:
    matchLabels:
      app: users-service
  template:
    metadata:
      labels:
        app: users-service
    spec:
      containers:
        - name: users-service
          image: org_name/users_service
          imagePullPolicy: Always
          ports:
            - containerPort: 5001
          env:
            - name: CONNECTION_STRING
              value: "..."
      imagePullSecrets:
        - name: docker-hub
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: actions-service
  labels:
    app: actions-service
spec:
  replicas: 1
  selector:
    matchLabels:
      app: actions-service
  template:
    metadata:
      labels:
        app: actions-service
    spec:
      containers:
        - name: actions-service
          image: org_name/actions_service
          imagePullPolicy: Always
          ports:
            - containerPort: 5003
          env:
            - name: CONNECTION_STRING
              value: "..."
      imagePullSecrets:
        - name: docker-hub
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: message-queue
  labels:
    app: message-queue
spec:
  replicas: 1
  selector:
    matchLabels:
      app: message-queue
  template:
    metadata:
      labels:
        app: message-queue
    spec:
      containers:
        - name: message-queue
          image: org_name/message_queue
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 5672
            - containerPort: 15672
      imagePullSecrets:
            - name: docker-hub
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: elasticsearch
  labels:
    app: elasticsearch
spec:
  replicas: 1
  selector:
    matchLabels:
      app: elasticsearch
  template:
    metadata:
      labels:
        app: elasticsearch
    spec:
      containers:
        - name: elasticsearch
          image: elasticsearch:7.6.0
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 9200
          env:
            - name: ELASTIC_PASSWORD
              value: ...
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: kibana
  labels:
    app: kibana
spec:
  replicas: 1
  selector:
    matchLabels:
      app: kibana
  template:
    metadata:
      labels:
        app: kibana
    spec:
      containers:
        - name: kibana
          image: kibana:7.6.0
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 5601
          env:
            - name: ELASTICSEARCH_HOSTS
              value: http://ELASTICSEARCH_SERVICE_HOST:ELASTICSEARCH_SERVICE_PORT
            - name: ELASTICSEARCH_USERNAME
              value: elastic
            - name: ELASTICSEARCH_PASSWORD
              value: ...
            - name: XPACK_MONITORING_ENABLED
              value: "true"
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: smtp-server
  labels:
    app: smtp-server
spec:
  replicas: 1
  selector:
    matchLabels:
      app: smtp-server
  template:
    metadata:
      labels:
        app: smtp-server
    spec:
      containers:
        - name: smtp-server
          image: mailhog/mailhog
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 1025
            - containerPort: 8025
---
apiVersion: v1
kind: Service
metadata:
  name: identity-service
  labels:
    app: identity-service
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:eu-west-2:...:certificate/...
spec:
  ports:
    - port: 443
      targetPort: 5000
      protocol: TCP
  selector:
    app: identity-service
  type: LoadBalancer
---
apiVersion: v1
kind: Service
metadata:
  name: users-service
  labels:
    app: users-service
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:eu-west-2:...:certificate/...
spec:
  ports:
    - port: 443
      targetPort: 5001
      protocol: TCP
  selector:
    app: users-service
  type: LoadBalancer
---
apiVersion: v1
kind: Service
metadata:
  name: actions-service
  labels:
    app: actions-service
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:eu-west-2:...:certificate/...
spec:
  ports:
    - port: 443
      targetPort: 5003
      protocol: TCP
  selector:
    app: actions-service
  type: LoadBalancer
---
apiVersion: v1
kind: Service
metadata:
  name: kibana
  labels:
    app: kibana
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:eu-west-2:...:certificate/...
spec:
  ports:
    - port: 5601
      targetPort: 5601
      protocol: TCP
  selector:
    app: kibana
  type: LoadBalancer
---
apiVersion: v1
kind: Service
metadata:
  name: elasticsearch
  labels:
    app: elasticsearch
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:eu-west-2:...:certificate/...
spec:
  ports:
    - port: 9200
      targetPort: 9200
      protocol: TCP
  selector:
    app: elasticsearch
  type: ClusterIP

Matt Matt · Accepted Answer · 2020-03-20T22:46:11

Use a single ingress controller to expose each service with ingress definitions. On AWS you can use an ALB as the ingress endpoint.

Each service will need a different hostname or /path to differentiate between them.

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: test-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - http:
      paths:
      - path: /identity
        backend:
          serviceName: identity-service
          servicePort: 5000
      - path: /users
        backend:
          serviceName: users-service
          servicePort: 5001
      - path: /actions
        backend:
          serviceName: actions-service
          servicePort: 5003
      - path: /kibana
        backend:
          serviceName: kibana
          servicePort: 5601

Then change the type of each service to ClusterIP

How can I combine the load balancers in Kubernetes?

1 Answers