A managed Kubernetes cluster at the edge must contain at least one Elastic Compute Service (ECS) instance. This topic describes how ECS instances work and how to add or delete ECS instances.

Cloud management nodes in edge computing

Cloud management nodes in edge computing
When you create a managed edge cluster, ACK@Edge automatically creates at least one ECS instance for the cluster and connects the ECS instance to the management nodes in the cloud. The ECS instance is used to deploy cloud management applications and allows you to deploy your customized cloud management applications. By default, the node-role.alibabacloud.com/addon: Effect: NoSchedule taint is attached to the nodes in the cloud. This ensures that edge services are not deployed on the management nodes. By default, the management nodes contain the following management applications in version 1.14.8-aliyunedge.1 or earlier.
  • alibaba-log-controller: the Log Service controller
  • alicloud-monitor-controller: the CloudMonitor controller
  • metric-server: the server for cluster monitoring
  • edge-tunnel-server: the server for the reverse O&M tunnel. It allows you to use the native Kubernetes API to access edge nodes, monitor containers, and use SSH to remotely run commands.

Deploy applications to management nodes in the cloud

If you want to deploy your customized management applications on management nodes in the cloud, for example, to deploy different types of operators, you must specify a toleration that matches the preceding taint and configure NodeSelector. The following example describes how to configure parameters.
     ...
      nodeSelector:
        alibabacloud.com/is-edge-worker: 'false'
        beta.kubernetes.io/arch: amd64
        beta.kubernetes.io/os: linux
      tolerations:
        - effect: NoSchedule
          key: node-role.alibabacloud.com/addon
          operator: Exists
      ...

Add a cloud management node

To add a cloud management node, you can perform the following steps. ACK@Edge will support ECS-based auto-scaling in later versions.

  1. Purchase an ECS instance in the VPC where the cluster is located.
    For more information about how to purchase an instance, see Create an ECS instance.
    Note Set the operating system to CentOS 7.6.
  2. In OpenAPI Explorer, call the AttachInstances operation to add the ECS instance to the cluster.
    The following example shows a request body:
    {
      "password": "Helloxxxx!",
      "tags":[],
      "instances": [
        "i-uf65mbpn1x8xxxxxx"
      ]
    }
    Parameter Description
    password The password for logging on to the ECS instance. The password must be 8 to 30 characters in length and must contain at least three of the following types: uppercase letters, lowercase letters, digits, and special characters.
    tags The tags of the nodes.
    • key: the name of the tag
    • value: the value of the tag
    instances The instances that exist in the cluster.

    For more information about API operations, seeAdd existing ECS instances to a cluster .