第 4 章 操作节点

• 以下命令列出所有节点：

  $ oc get nodes
  
  NAME                   STATUS    ROLES     AGE       VERSION
  master.example.com     Ready     master    7h        v1.17.1
  node1.example.com      Ready     worker    7h        v1.17.1
  node2.example.com      Ready     worker    7h        v1.17.1

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• -wide 选项可提供所有节点的附加信息。

  $ oc get nodes -o wide

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• 以下命令列出一个节点的相关信息：

  $ oc get node <node>

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  这些命令输出中的 STATUS 列可显示节点的以下状况：

  Expand

  表 4.1. 节点状况

  状况	描述
  Ready	节点通过返回 True 来报告其自身对 API 服务器的就绪度。
  NotReady	其中一个底层组件（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。

  Show more

• 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>

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  例如：

  $ oc describe node node1.example.com
  
  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:                         v1.17.1
   Kube-Proxy Version:                      v1.17.1
  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.
   ...

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  1

  节点的名称。

  2

  节点的角色，可以是 master 或 worker。

  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

  节点状况。

  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。

流程

• 列出一个或多个节点上的所有或选定 pod：

  $ oc describe node <node1> <node2>

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  例如：

  $ oc describe node ip-10-0-128-218.ec2.internal

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• 列出选定节点上的所有或选定 pod：

  $ oc describe --selector=<node_selector>
  $ oc describe -l=<pod_selector>

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  例如：

  $ oc describe node  --selector=beta.kubernetes.io/os
  $ oc describe node -l node-role.kubernetes.io/worker

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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
  
  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%

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• 查看具有标签的节点的用量统计信息：

  $ oc adm top node --selector=''

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  您必须选择过滤所基于的选择器（标签查询）。支持 =、== 和 !=。