Container Service for Kubernetes:Use the CCM to deploy services across clusters

Scenario 1: Distribute traffic to nodes in a cluster and ECS instances outside the cluster

You can use the CCM to associate both nodes in a cluster and ECS instances outside the cluster with a CLB instance. This way, the CLB instance can distribute traffic to nodes in your cluster and nodes outside your cluster.

1. Create a file named my-nginx-svc.yaml and copy the following content to the file:

   apiVersion: v1
   kind: Service
   metadata:
     annotations:
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: ${YOUR_LB_ID}             // Replace ${YOUR_LB_ID} with the ID of the CLB instance that you created in the CLB console. 
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-force-override-listeners: "false"  // If you set the value to false, the CCM does not manage listeners for the CLB instance. 
     labels:
       app: nginx
     name: my-nginx-svc
     namespace: default
   spec:
     ports:
     - port: 80
       protocol: TCP
       targetPort: 80
     selector:   // Set the selector to the value of the matchLabels parameter in the my-nginx.yaml file. In this example, the selector is set to app: nginx. This associates the Service with the backend application. 
       app: nginx      
     type: LoadBalancer

   Note

   • The CCM uses the specified CLB instance for load balancing and configures the CLB instance based on the specified annotations. For example, the CCM automatically creates multiple vServer groups for the CLB instance.
   • The CCM supports a variety of annotations that you can use to customize load balancing features by using Alibaba Cloud services. For information, see Use annotations to configure load balancing.
2. Run the following command to create a Service named my-nginx-svc:

   kubectl apply -f my-nginx-svc.yaml

3. Log on to the CLB console, create listeners for the CLB instance, and then associate the vServer groups created by the CCM with the CLB instance.
   For more information, see Listener overview.

   Important The listening ports of the CLB instance must be the same as the Service ports.
4. Log on to the CLB console and add ECS instances outside your cluster to the vServer groups created by the CCM. Then, specify weights for these ECS instances.
   For more information, see Create and manage a vServer group.

   After you complete the configuration, go to the Edit VServer Group page of the CLB instance in the CLB console. You can view the node (callout 1) inside your cluster and the ECS instance (callout 2) outside your cluster, as shown in the following figure. Application scaling within your cluster does not affect the ECS instance outside your cluster.

   

Scenario 2: Set weights for nodes in the cluster and ECS instances outside the cluster

Notes

• You cannot share vServer groups among CLB instances.
• A vServer group can be associated only with one port.
• The weights of the nodes in the cluster are set by the CCM. You need to manually set weights for the ECS instances outside the cluster.

Procedure

1. Log on to the CLB console and create a vServer group with no servers. Record the ID of the vServer group.
   For more information, see Create and manage a vServer group.
2. Create a listener for the CLB instance and associate the listener with the vServer group that you created. Record the ID of the CLB instance.
   For more information, see Listener overview.

   Important The listening ports of the CLB instance must be the same as the Service ports.
3. Add the ECS instance outside the cluster to the vServer group and set the weight of the ECS instance.
   For more information, see Create and manage a vServer group.
4. Create a file named service.yaml and copy the following content to the file:

   apiVersion: v1
   kind: Service
   metadata:
     annotations:
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: "lb-xxxxx"  // Replace lb-xxxxx with the ID of the CLB instance that you created in the CLB console. 
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vgroup-port: "${YOUR_VGROUP_ID}:80"   // Replace ${YOUR_VGROUP_ID} with the ID of the vServer group that you created.     
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-weight: "60"   // Set the Service weight. This annotation is optional. 
     name: nginx-svc
     namespace: default
   spec:
     ports:
     - name: http
       port: 80
       protocol: TCP
       targetPort: 80
     selector:
       app: nginx
     sessionAffinity: None
     type: LoadBalancer

5. Run the following command to create a Service named service:

   kubectl apply -f service.yaml

   After you complete the configuration, go to the Edit VServer Group page of the CLB instance in the CLB console. You can view the node (callout 1) inside your cluster and the ECS instance (callout 2) outside your cluster, as shown in the following figure. Application scaling within your cluster does not affect the ECS instance outside your cluster.

   

Scenario 3: Distribute traffic to multiple Kubernetes clusters

In most cases, an enterprise takes various measures, such as data backup and disaster recovery across clusters, to ensure high availability for services. To achieve this goal, the enterprise can use a CLB instance to distribute traffic to multiple Kubernetes clusters based on the weights of backend servers, as shown in the following figure.

1. Log on to the CLB console and create a vServer group with no servers.
   For more information, see Create and manage a vServer group.
2. Log on to the CLB console, create listeners for the CLB instance, and then associate the vServer groups created in the preceding step with the CLB instance.
   For more information, see Listener overview.

   Important The listening ports of the CLB instance must be the same as the Service ports.
3. Create a file named service-a.yaml in Cluster A and copy the following content to the file:

   apiVersion: v1
   kind: Service
   metadata:
     annotations:
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: "${YOUR_LB_ID}"                   // Replace ${YOUR_LB_ID} with the ID of the CLB instance that you created in the CLB console. 
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vgroup-port: "${YOUR_VGROUP_ID}:80"   // Replace ${YOUR_VGROUP_ID} with the ID of the vServer group that you created. 
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-weight: "20"                          // Set the Service weight. This annotation is optional. 
     name: service-a     // The name of the file. 
     namespace: default
   spec:
     ports:
     - name: http
       port: 80
       protocol: TCP
       targetPort: 80
     selector:
       app: nginx
     sessionAffinity: None
     type: LoadBalancer

   Note If you want to set service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vgroup-port to multiple port-to-vServer group mappings, separate the mappings with commas (,). Example: "${YOUR_VGROUP_ID_1}:80, ${YOUR_VGROUP_ID_2}:443".
4. Run the following command to create a Service named service-a:

   kubectl apply -f service-a.yaml

5. Create a file named service-b.yaml in Cluster B and copy the following content to the file:

   apiVersion: v1
   kind: Service
   metadata:
     annotations:
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-id: "${YOUR_LB_ID}"                  // Replace ${YOUR_LB_ID} with the ID of the CLB instance that you created in the CLB console. 
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vgroup-port: "${YOUR_VGROUP_ID}:80"  // Replace ${YOUR_VGROUP_ID} with the ID of the vServer group that you created. 
       service.beta.kubernetes.io/alibaba-cloud-loadbalancer-weight: "80"                         // Set the Service weight. This annotation is optional. 
     name: service-b      // The name of the file. 
     namespace: default
   spec:
     ports:
     - name: http
       port: 80
       protocol: TCP
       targetPort: 80
     selector:
       app: nginx
     sessionAffinity: None
     type: LoadBalancer

   Note If you want to set service.beta.kubernetes.io/alibaba-cloud-loadbalancer-vgroup-port to multiple port-to-vServer group mappings, separate the mappings with commas (,). Example: "${YOUR_VGROUP_ID_1}:80, ${YOUR_VGROUP_ID_2}:443".
6. Run the following command to create a Service named service-b:

   kubectl apply -f service-b.yaml

   After the configuration is completed, go to the Edit VServer Group page of the CLB instance in the CLB console. You can view the nodes of Cluster A and also nodes of Cluster B. The weight of each node is automatically configured based on the service.beta.kubernetes.io/alibaba-cloud-loadbalancer-weight annotation. Application scaling results are automatically synchronized to the vServer groups of the CLB instance.