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第 5 章 操作节点

5.1. 查看和列出 OpenShift Container Platform 集群中的节点

您可以列出集群中的所有节点,以获取节点的相关信息,如状态、年龄、内存用量和其他详情。

在执行节点管理操作时,CLI 与代表实际节点主机的节点对象交互。主控机(master)使用来自节点对象的信息执行健康检查,以此验证节点。

5.1.1. 关于列出集群中的所有节点

您可以获取集群中节点的详细信息。

  • 以下命令列出所有节点:

    $ oc get nodes

    以下示例是具有健康节点的集群:

    $ oc get nodes

    输出示例

    NAME                   STATUS    ROLES     AGE       VERSION
    master.example.com     Ready     master    7h        v1.19.0
    node1.example.com      Ready     worker    7h        v1.19.0
    node2.example.com      Ready     worker    7h        v1.19.0

    以下示例是具有一个不健康节点的集群:

    $ oc get nodes

    输出示例

    NAME                   STATUS                      ROLES     AGE       VERSION
    master.example.com     Ready                       master    7h        v1.20.0
    node1.example.com      NotReady,SchedulingDisabled worker    7h        v1.20.0
    node2.example.com      Ready                       worker    7h        v1.20.0

    触发 NotReady 状态的条件在本节中显示。

  • -o wide 选项提供有关节点的附加信息。

    $ oc get nodes -o wide

    输出示例

    NAME                STATUS   ROLES    AGE    VERSION           INTERNAL-IP    EXTERNAL-IP   OS-IMAGE                                                      KERNEL-VERSION                 CONTAINER-RUNTIME
    master.example.com  Ready    master   171m   v1.20.0+39c0afe   10.0.129.108   <none>        Red Hat Enterprise Linux CoreOS 48.83.202103210901-0 (Ootpa)   4.18.0-240.15.1.el8_3.x86_64   cri-o://1.21.0-30.rhaos4.8.gitf2f339d.el8-dev
    node1.example.com   Ready    worker   72m    v1.20.0+39c0afe   10.0.129.222   <none>        Red Hat Enterprise Linux CoreOS 48.83.202103210901-0 (Ootpa)   4.18.0-240.15.1.el8_3.x86_64   cri-o://1.21.0-30.rhaos4.8.gitf2f339d.el8-dev
    node2.example.com   Ready    worker   164m   v1.20.0+39c0afe   10.0.142.150   <none>        Red Hat Enterprise Linux CoreOS 48.83.202103210901-0 (Ootpa)   4.18.0-240.15.1.el8_3.x86_64   cri-o://1.21.0-30.rhaos4.8.gitf2f339d.el8-dev

  • 以下命令列出一个节点的相关信息:

    $ oc get node <node>

    例如:

    $ oc get node node1.example.com

    输出示例

    NAME                   STATUS    ROLES     AGE       VERSION
    node1.example.com      Ready     worker    7h        v1.20.0

  • 以下命令提供有关特定节点的更多详细信息,包括发生当前状况的原因:

    $ oc describe node <node>

    例如:

    $ oc describe node node1.example.com

    输出示例

    Name:               node1.example.com 1
    Roles:              worker 2
    Labels:             beta.kubernetes.io/arch=amd64   3
                        beta.kubernetes.io/instance-type=m4.large
                        beta.kubernetes.io/os=linux
                        failure-domain.beta.kubernetes.io/region=us-east-2
                        failure-domain.beta.kubernetes.io/zone=us-east-2a
                        kubernetes.io/hostname=ip-10-0-140-16
                        node-role.kubernetes.io/worker=
    Annotations:        cluster.k8s.io/machine: openshift-machine-api/ahardin-worker-us-east-2a-q5dzc  4
                        machineconfiguration.openshift.io/currentConfig: worker-309c228e8b3a92e2235edd544c62fea8
                        machineconfiguration.openshift.io/desiredConfig: worker-309c228e8b3a92e2235edd544c62fea8
                        machineconfiguration.openshift.io/state: Done
                        volumes.kubernetes.io/controller-managed-attach-detach: true
    CreationTimestamp:  Wed, 13 Feb 2019 11:05:57 -0500
    Taints:             <none>  5
    Unschedulable:      false
    Conditions:                 6
      Type             Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
      ----             ------  -----------------                 ------------------                ------                       -------
      OutOfDisk        False   Wed, 13 Feb 2019 15:09:42 -0500   Wed, 13 Feb 2019 11:05:57 -0500   KubeletHasSufficientDisk     kubelet has sufficient disk space available
      MemoryPressure   False   Wed, 13 Feb 2019 15:09:42 -0500   Wed, 13 Feb 2019 11:05:57 -0500   KubeletHasSufficientMemory   kubelet has sufficient memory available
      DiskPressure     False   Wed, 13 Feb 2019 15:09:42 -0500   Wed, 13 Feb 2019 11:05:57 -0500   KubeletHasNoDiskPressure     kubelet has no disk pressure
      PIDPressure      False   Wed, 13 Feb 2019 15:09:42 -0500   Wed, 13 Feb 2019 11:05:57 -0500   KubeletHasSufficientPID      kubelet has sufficient PID available
      Ready            True    Wed, 13 Feb 2019 15:09:42 -0500   Wed, 13 Feb 2019 11:07:09 -0500   KubeletReady                 kubelet is posting ready status
    Addresses:   7
      InternalIP:   10.0.140.16
      InternalDNS:  ip-10-0-140-16.us-east-2.compute.internal
      Hostname:     ip-10-0-140-16.us-east-2.compute.internal
    Capacity:    8
     attachable-volumes-aws-ebs:  39
     cpu:                         2
     hugepages-1Gi:               0
     hugepages-2Mi:               0
     memory:                      8172516Ki
     pods:                        250
    Allocatable:
     attachable-volumes-aws-ebs:  39
     cpu:                         1500m
     hugepages-1Gi:               0
     hugepages-2Mi:               0
     memory:                      7558116Ki
     pods:                        250
    System Info:    9
     Machine ID:                              63787c9534c24fde9a0cde35c13f1f66
     System UUID:                             EC22BF97-A006-4A58-6AF8-0A38DEEA122A
     Boot ID:                                 f24ad37d-2594-46b4-8830-7f7555918325
     Kernel Version:                          3.10.0-957.5.1.el7.x86_64
     OS Image:                                Red Hat Enterprise Linux CoreOS 410.8.20190520.0 (Ootpa)
     Operating System:                        linux
     Architecture:                            amd64
     Container Runtime Version:               cri-o://1.16.0-0.6.dev.rhaos4.3.git9ad059b.el8-rc2
     Kubelet Version:                         v1.19.0
     Kube-Proxy Version:                      v1.19.0
    PodCIDR:                                  10.128.4.0/24
    ProviderID:                               aws:///us-east-2a/i-04e87b31dc6b3e171
    Non-terminated Pods:                      (13 in total)  10
      Namespace                               Name                                   CPU Requests  CPU Limits  Memory Requests  Memory Limits
      ---------                               ----                                   ------------  ----------  ---------------  -------------
      openshift-cluster-node-tuning-operator  tuned-hdl5q                            0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-dns                           dns-default-l69zr                      0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-image-registry                node-ca-9hmcg                          0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-ingress                       router-default-76455c45c-c5ptv         0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-machine-config-operator       machine-config-daemon-cvqw9            20m (1%)      0 (0%)      50Mi (0%)        0 (0%)
      openshift-marketplace                   community-operators-f67fh              0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-monitoring                    alertmanager-main-0                    50m (3%)      50m (3%)    210Mi (2%)       10Mi (0%)
      openshift-monitoring                    grafana-78765ddcc7-hnjmm               100m (6%)     200m (13%)  100Mi (1%)       200Mi (2%)
      openshift-monitoring                    node-exporter-l7q8d                    10m (0%)      20m (1%)    20Mi (0%)        40Mi (0%)
      openshift-monitoring                    prometheus-adapter-75d769c874-hvb85    0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-multus                        multus-kw8w5                           0 (0%)        0 (0%)      0 (0%)           0 (0%)
      openshift-sdn                           ovs-t4dsn                              100m (6%)     0 (0%)      300Mi (4%)       0 (0%)
      openshift-sdn                           sdn-g79hg                              100m (6%)     0 (0%)      200Mi (2%)       0 (0%)
    Allocated resources:
      (Total limits may be over 100 percent, i.e., overcommitted.)
      Resource                    Requests     Limits
      --------                    --------     ------
      cpu                         380m (25%)   270m (18%)
      memory                      880Mi (11%)  250Mi (3%)
      attachable-volumes-aws-ebs  0            0
    Events:     11
      Type     Reason                   Age                From                      Message
      ----     ------                   ----               ----                      -------
      Normal   NodeHasSufficientPID     6d (x5 over 6d)    kubelet, m01.example.com  Node m01.example.com status is now: NodeHasSufficientPID
      Normal   NodeAllocatableEnforced  6d                 kubelet, m01.example.com  Updated Node Allocatable limit across pods
      Normal   NodeHasSufficientMemory  6d (x6 over 6d)    kubelet, m01.example.com  Node m01.example.com status is now: NodeHasSufficientMemory
      Normal   NodeHasNoDiskPressure    6d (x6 over 6d)    kubelet, m01.example.com  Node m01.example.com status is now: NodeHasNoDiskPressure
      Normal   NodeHasSufficientDisk    6d (x6 over 6d)    kubelet, m01.example.com  Node m01.example.com status is now: NodeHasSufficientDisk
      Normal   NodeHasSufficientPID     6d                 kubelet, m01.example.com  Node m01.example.com status is now: NodeHasSufficientPID
      Normal   Starting                 6d                 kubelet, m01.example.com  Starting kubelet.
     ...

    1
    节点的名称。
    2
    节点的角色,可以是 masterworker
    3
    应用到节点的标签。
    4
    应用到节点的注解。
    5
    应用到节点的污点。
    6
    节点条件和状态。conditions 小节列出了 ReadyPIDPressurePIDPressureMemoryPressureDiskPressureOutOfDisk 状态。本节稍后将描述这些条件。
    7
    节点的 IP 地址和主机名。
    8
    pod 资源和可分配的资源。
    9
    节点主机的相关信息。
    10
    节点上的 pod。
    11
    节点报告的事件。

在显示的节点信息中,本节显示的命令输出中会出现以下节点状况:

表 5.1. 节点状况

状况描述

Ready

如果为 true,节点处于健康状态,并可以接受 pod。如果为 false,则节点处于不健康的状态,不接受 pod。如果为 unknown,代表节点控制器在 node-monitor-grace-period 时间内(默认为 40 秒)还没有收到来自节点的心跳信号。

DiskPressure

如果为 true,代表磁盘容量较低。

MemoryPressure

如果为 true,代表节点内存较低。

PIDPressure

如果为 true,代表节点上的进程太多。

OutOfDisk

如果为 true,代表节点上的可用空间不足,无法添加新 pod。

NetworkUnavailable

如果为 true,代表节点的网络不会被正确配置。

NotReady

如果为true,代表一个底层组件(如容器运行时或网络)遇到了问题或尚未配置。

SchedulingDisabled

无法通过调度将 Pod 放置到节点上。

5.1.2. 列出集群中某一节点上的 pod

您可以列出特定节点上的所有 pod。

流程

  • 列出一个或多个节点上的所有或选定 pod:

    $ oc describe node <node1> <node2>

    例如:

    $ oc describe node ip-10-0-128-218.ec2.internal
  • 列出选定节点上的所有或选定 pod:

    $ oc describe --selector=<node_selector>
    $ oc describe node  --selector=kubernetes.io/os

    或者:

    $ oc describe -l=<pod_selector>
    $ oc describe node -l node-role.kubernetes.io/worker
  • 列出特定节点上的所有 pod,包括终止的 pod:

    $ oc get pod --all-namespaces --field-selector=spec.nodeName=<nodename>

5.1.3. 查看节点上的内存和 CPU 用量统计

您可以显示节点的用量统计,这些统计信息为容器提供了运行时环境。这些用量统计包括 CPU、内存和存储的消耗。

先决条件

  • 您必须有 cluster-reader 权限才能查看用量统计。
  • 必须安装 Metrics 才能查看用量统计。

流程

  • 查看用量统计:

    $ oc adm top nodes

    输出示例

    NAME                                   CPU(cores)   CPU%      MEMORY(bytes)   MEMORY%
    ip-10-0-12-143.ec2.compute.internal    1503m        100%      4533Mi          61%
    ip-10-0-132-16.ec2.compute.internal    76m          5%        1391Mi          18%
    ip-10-0-140-137.ec2.compute.internal   398m         26%       2473Mi          33%
    ip-10-0-142-44.ec2.compute.internal    656m         43%       6119Mi          82%
    ip-10-0-146-165.ec2.compute.internal   188m         12%       3367Mi          45%
    ip-10-0-19-62.ec2.compute.internal     896m         59%       5754Mi          77%
    ip-10-0-44-193.ec2.compute.internal    632m         42%       5349Mi          72%

  • 查看具有标签的节点的用量统计信息:

    $ oc adm top node --selector=''

    您必须选择过滤所基于的选择器(标签查询)。支持 ===!=