Steps to run the samples

Config Kubernetes

There are two ways to use Kubernetes as registry in dubbo.

1. API Server

   dubbo-samples-kubernetes-apiserver is the sample of API server.

   1.1 Token

   In order to access Api Server, you need to set up a Service Account with the following permissions in your Kubernetes Cluster.

   • Read and Write permission to Pods
   • Read permission to Services
   • Read permission to Endpoints

   Here is an example to create this.

   apiVersion: v1
   kind: Namespace
   metadata:
     name: dubbo-demo
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: Role
   metadata:
     namespace: dubbo-demo
     name: dubbo-role
   rules:
   - apiGroups: [""]
     resources: ["pods"]
     verbs: ["get", "watch", "list", "update", "patch"]
   - apiGroups: [""] 
     resources: ["services", "endpoints"]
     verbs: ["get", "watch", "list"]
   ---
   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: dubbo-sa
     namespace: dubbo-demo
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: RoleBinding
   metadata:
     name: dubbo-sa-bind
     namespace: dubbo-demo
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: Role
     name: dubbo-role
   subjects:
   - kind: ServiceAccount
     name: dubbo-sa
   

   Then, Retrieve the token for the dubbo-sa service account.

   kubectl -n dubbo-demo describe secret $(kubectl -n dubbo-demo get secret | grep dubbo-sa | awk '{print $1}')
   

   Copy the <authentication_token> value from the output and replace with oauthToken property in properties file:

   Name:         dubbo-sa-token-2g5c6
   Namespace:    dubbo-demo
   Labels:       <none>
   Annotations:  kubernetes.io/service-account.name: dubbo-sa
                 kubernetes.io/service-account.uid: 963e68f3-738d-4f10-bf32-92a3fbf44774
   
   Type:  kubernetes.io/service-account-token
   
   Data
   ====
   ca.crt:     1025 bytes
   namespace:  10 bytes
   token:      <authentication_token>
   

   1.2 API URL

   Get the API URL by running this command:

   kubectl cluster-info | grep 'Kubernetes master' | awk '/http/ {print $NF}'
   

   You can get the output like:

   https://<API Server ip>:<API Server port>
   

   Copy and to properties.

   Notice: protocol is needless to specify, dubbo will use https protocol as default.

2. DNS

   dubbo-samples-kubernetes-dns is the sample of DNS.

   In order to use DNS as registry, you need to retrieve DNS host from Kubernetes. You can get it by this.

   kubectl get service -n kube-system | grep kube-dns
   

   kube-dns   ClusterIP   <DNS ip>      <none>   53/UDP,53/TCP,9153/TCP   68d
   

   Copy to properties.

Start demo

1. Build maven project and deploy to docker registry with Dockerfile.

2. Deploy the provider to kubernetes cluster.

   apiVersion: apps/v1
   kind: ReplicaSet
   metadata:
     name: kubernetes-apiserver-demo-provider
   spec:
     replicas: 3
     selector:
       matchLabels:
         tier: apiserver-demo-provider
     template:
       metadata:
         labels:
           tier: apiserver-demo-provider
           io.dubbo: MyTest
       spec:
         containers:
         - name: server
           image: < Your image path >
           ports:
             - containerPort: 20880
           livenessProbe:
             httpGet:
               path: /live
               port: 22222
             initialDelaySeconds: 5
             periodSeconds: 5
           readinessProbe:
             httpGet:
               path: /ready
               port: 22222
             initialDelaySeconds: 5
             periodSeconds: 5
           startupProbe:
             httpGet:
               path: /startup
               port: 22222
             failureThreshold: 30
             periodSeconds: 10
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: kubernetes-apiserver-demo-provider
   spec:
     clusterIP: None
     selector:
       io.dubbo: MyTest
     ports:
       - protocol: TCP
         port: 20880
         targetPort: 20880
   

3. Run Dubbo consumer demo org.apache.dubbo.samples.ConsumerBootstrap.main