Kubernetes Metrics Server

Add-on Overview

From version 1.8 onwards, Kubernetes provides resource usage metrics, such as the container CPU and memory usage, through the Metrics API. These metrics can be directly accessed by users (for example, by using the kubectl top command) or used by controllers (for example, Horizontal Pod Autoscaler) in a cluster for decision-making. The specific component is metrics-server, which is used to substitute for Heapster for providing the similar functions. Heapster has been gradually abandoned since v1.11.

Add-on Parameters

**Table 1** Parameters
Parameter	Mandatory	Type	Description
basic	No	object	Basic configuration parameters, which do not need to be specified
flavor	Yes	Table 2 object	Flavor parameters
custom	Yes	Table 3 object	Custom parameters

**Table 2** flavor
Parameter	Mandatory	Type	Description
description	No	String	Add-on description
name	Yes	String	Add-on specification name. The value is fixed at Single-instance.
replicas	Yes	String	Number of pods. The default value is 1.
resources	Yes	resources object	Container resource (CPU and memory) quotas

**Table 3** custom
Parameter	Mandatory	Type	Description
multiAZBalance	No	Bool	Whether the equivalent mode of multi-AZ deployment is enabled. If this function is enabled, the equivalent mode is used.
multiAZEnabled	No	Bool	Whether to deploy the add-on pods in multiple AZs. The default value is false. If this parameter is set to true, cross-AZ deployment is forcibly performed. If this parameter is set to false, cross-AZ deployment is preferred.
tolerations	No	List<Object> Table 6	Tolerations of the add-on
node_match_expressions	No	List<Object> Table 6	Node affinity configuration of the add-on

**Table 4** Data structure of the resources field
Parameter	Mandatory	Type	Description
limitsCpu	Yes	String	CPU size limit (unit: m)
limitsMem	Yes	String	Memory size limit (unit: Mi)
name	Yes	String	Add-on name. The value is fixed at metrics-server.
requestsCpu	Yes	String	Requested CPU size (unit: m)
requestsMem	Yes	String	Requested memory size (unit: Mi)

**Table 5** Taints and tolerations
Parameter	Mandatory	Type	Description
key	No	String	Taint key
effect	No	String	Taint policy
operator	No	String	Operator
tolerationSeconds	No	Int	Toleration time window

**Table 6** nodeMatchExpresssion node affinity
Parameter	Mandatory	Type	Description
key	No	String	Taint key
values	No	List<String>	Node affinity name
operator	No	String	Operator

Example Request

{
  "kind": "Addon",
  "apiVersion": "v3",
  "metadata": {
    "annotations": {
      "addon.install/type": "install"
    }
  },
  "spec": {
    "clusterID": "b78fb690-b82c-11ee-83cf-0255ac100b0f",
    "version": "1.3.39",
    "addonTemplateName": "metrics-server",
    "values": {
      "basic": {
        "image_version": "v0.6.2",
        "swr_addr": "***",
        "swr_user": "***",
        "rbac_enabled": true,
        "cluster_version": "v1.23"
      },
      "flavor": {
        "description": "Has only one instance",
        "name": "Single",
        "replicas": 1,
        "resources": [
          {
            "limitsCpu": "1000m",
            "limitsMem": "1000Mi",
            "name": "metrics-server",
            "requestsCpu": "100m",
            "requestsMem": "300Mi"
          }
        ],
        "category": [
          "CCE",
          "Turbo"
        ]
      },
      "custom": {
        "annotations": {},
        "multiAZBalance": false,
        "multiAZEnabled": false,
        "node_match_expressions": [],
        "tolerations": [
          {
            "key": "node.kubernetes.io/not-ready",
            "operator": "Exists",
            "effect": "NoExecute",
            "tolerationSeconds": 60
          },
          {
            "key": "node.kubernetes.io/unreachable",
            "operator": "Exists",
            "effect": "NoExecute",
            "tolerationSeconds": 60
          }
        ]
      }
    }
  }
}

Parent Topic: Add-on Instance Parameters

Previous topic: NGINX Ingress Controller

Next topic: CCE Advanced HPA