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
          }
        ]
      }
    }
  }
}