本文记录自己使用K8S时的相关操作命令。

查看cluster-info

[root@k8s-master-1 ~]# kubectl cluster-info
Kubernetes control plane is running at https://192.168.17.130:6443
CoreDNS is running at https://192.168.17.130:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

查看cluster-info的dump信息

# 显示的内容太多,故取前25行做演示
[root@k8s-master-1 ~]# kubectl cluster-info dump | head -n 25
{
    "kind": "NodeList",
    "apiVersion": "v1",
    "metadata": {
        "resourceVersion": "39548"
    },
    "items": [
        {
            "metadata": {
                "name": "k8s-master-1",
                "uid": "3c39ab3c-7b3c-45c7-b6f6-7625dd035a11",
                "resourceVersion": "39373",
                "creationTimestamp": "2021-05-04T07:11:18Z",
                "labels": {
                    "beta.kubernetes.io/arch": "amd64",
                    "beta.kubernetes.io/os": "linux",
                    "kubernetes.io/arch": "amd64",
                    "kubernetes.io/hostname": "k8s-master-1",
                    "kubernetes.io/os": "linux",
                    "node-role.kubernetes.io/control-plane": "",
                    "node-role.kubernetes.io/master": "",
                    "node.kubernetes.io/exclude-from-external-load-balancers": ""
                },
    …………

查看pods

[root@k8s-master-1 ~]# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-784894895c-5pvll   1/1     Running   1          22h
nginx-deployment-784894895c-vfnp7   1/1     Running   1          22h

查看deployment

[root@k8s-master-1 ~]# kubectl get deployment -n kube-system
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
coredns   2/2     2            2           23h

查看services

[root@k8s-master-1 ~]# kubectl get svc
NAME               TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes         ClusterIP   10.1.0.1       <none>        443/TCP        23h
nginx-deployment   NodePort    10.1.126.251   <none>        80:30660/TCP   22h

[root@k8s-master-1 ~]# kubectl get svc -o wide
NAME               TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE   SELECTOR
kubernetes         ClusterIP   10.1.0.1       <none>        443/TCP        23h   <none>
nginx-deployment   NodePort    10.1.126.251   <none>        80:30660/TCP   22h   k8s-app=nginx-deployment

[root@k8s-master-1 ~]# kubectl get svc -n kube-system -o wide
NAME       TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE   SELECTOR
kube-dns   ClusterIP   10.1.0.10    <none>        53/UDP,53/TCP,9153/TCP   23h   k8s-app=kube-dns

查看nodes

[root@k8s-master-1 ~]# kubectl get nodes
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master-1   Ready    control-plane,master   23h   v1.21.0
k8s-node-1     Ready    <none>                 23h   v1.21.0
k8s-node-2     Ready    <none>                 23h   v1.21.0

[root@k8s-master-1 ~]# kubectl get nodes -o wide
NAME           STATUS   ROLES                  AGE   VERSION   INTERNAL-IP      EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION                CONTAINER-RUNTIME
k8s-master-1   Ready    control-plane,master   23h   v1.21.0   192.168.17.130   <none>        CentOS Linux 7 (Core)   3.10.0-1160.25.1.el7.x86_64   docker://20.10.6
k8s-node-1     Ready    <none>                 23h   v1.21.0   192.168.17.131   <none>        CentOS Linux 7 (Core)   3.10.0-1160.25.1.el7.x86_64   docker://20.10.6
k8s-node-2     Ready    <none>                 23h   v1.21.0   192.168.17.133   <none>        CentOS Linux 7 (Core)   3.10.0-1160.25.1.el7.x86_64   docker://20.10.6

查看Service Account

[root@k8s-master-1 ~]# kubectl get sa --all-namespaces
NAMESPACE              NAME                                 SECRETS   AGE
default                default                              1         23h
kube-node-lease        default                              1         23h
kube-public            default                              1         23h
kube-system            attachdetach-controller              1         23h
kube-system            bootstrap-signer                     1         23h
kube-system            certificate-controller               1         23h
kube-system            clusterrole-aggregation-controller   1         23h
kube-system            coredns                              1         23h
kube-system            cronjob-controller                   1         23h
kube-system            daemon-set-controller                1         23h
kube-system            default                              1         23h
kube-system            deployment-controller                1         23h
kube-system            disruption-controller                1         23h
kube-system            endpoint-controller                  1         23h
kube-system            endpointslice-controller             1         23h
kube-system            endpointslicemirroring-controller    1         23h
kube-system            ephemeral-volume-controller          1         23h
kube-system            expand-controller                    1         23h
kube-system            flannel                              1         23h
kube-system            generic-garbage-collector            1         23h
kube-system            horizontal-pod-autoscaler            1         23h
kube-system            job-controller                       1         23h
kube-system            kube-proxy                           1         23h
kube-system            namespace-controller                 1         23h
kube-system            node-controller                      1         23h
kube-system            persistent-volume-binder             1         23h
kube-system            pod-garbage-collector                1         23h
kube-system            pv-protection-controller             1         23h
kube-system            pvc-protection-controller            1         23h
kube-system            replicaset-controller                1         23h
kube-system            replication-controller               1         23h
kube-system            resourcequota-controller             1         23h
kube-system            root-ca-cert-publisher               1         23h
kube-system            service-account-controller           1         23h
kube-system            service-controller                   1         23h
kube-system            statefulset-controller               1         23h
kube-system            token-cleaner                        1         23h
kube-system            ttl-after-finished-controller        1         23h
kube-system            ttl-controller                       1         23h
kubernetes-dashboard   admin-user                           1         23h
kubernetes-dashboard   default                              1         23h
kubernetes-dashboard   kubernetes-dashboard                 1         23h

查看cluster DNS Services信息

[root@k8s-master-1 ~]# kubectl get service -l k8s-app=kube-dns --namespace=kube-system
NAME       TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
kube-dns   ClusterIP   10.1.0.10    <none>        53/UDP,53/TCP,9153/TCP   23h

查看cluster DNS replication controllers

[root@k8s-master-1 ~]# kubectl get pod --selector k8s-app=kube-dns --namespace=kube-system
NAME                       READY   STATUS    RESTARTS   AGE
coredns-558bd4d5db-drmtf   1/1     Running   1          23h
coredns-558bd4d5db-pgd7r   1/1     Running   1          23h

查看components

[root@k8s-master-1 ~]# kubectl -s https://192.168.17.130:6443 get componentstatus
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused   
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused   
etcd-0               Healthy     {"health":"true"}                                                                             

此处Unhealthy是因为相关服务配置文件kube-scheduler.yaml及kube-controller-manager.yaml默认的监听端口非10251和10252所致

查看endpoint

[root@k8s-master-1 ~]# kubectl get endpoints
NAME               ENDPOINTS                           AGE
kubernetes         192.168.17.130:6443                 23h
nginx-deployment   10.244.1.4:30080,10.244.2.5:30080   22h

查看node 列表

[root@k8s-master-1 ~]# kubectl -s https://192.168.17.130:6443 get nodes
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master-1   Ready    control-plane,master   23h   v1.21.0
k8s-node-1     Ready    <none>                 23h   v1.21.0
k8s-node-2     Ready    <none>                 23h   v1.21.0

[root@k8s-master-1 ~]# kubectl get nodes
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master-1   Ready    control-plane,master   23h   v1.21.0
k8s-node-1     Ready    <none>                 23h   v1.21.0
k8s-node-2     Ready    <none>                 23h   v1.21.0

查看node详细信息

[root@k8s-master-1 ~]# kubectl get nodes
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master-1   Ready    control-plane,master   23h   v1.21.0
k8s-node-1     Ready    <none>                 23h   v1.21.0
k8s-node-2     Ready    <none>                 23h   v1.21.0
[root@k8s-master-1 ~]# kubectl describe node k8s-node-1
Name:               k8s-node-1
Roles:              <none>
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=k8s-node-1
                    kubernetes.io/os=linux
Annotations:        flannel.alpha.coreos.com/backend-data: {"VNI":1,"VtepMAC":"66:11:ba:1b:7b:81"}
                    flannel.alpha.coreos.com/backend-type: vxlan
                    flannel.alpha.coreos.com/kube-subnet-manager: true
                    flannel.alpha.coreos.com/public-ip: 192.168.17.131
                    kubeadm.alpha.kubernetes.io/cri-socket: /var/run/dockershim.sock
                    node.alpha.kubernetes.io/ttl: 0
                    volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp:  Tue, 04 May 2021 15:12:23 +0800
Taints:             <none>
Unschedulable:      false
Lease:
  HolderIdentity:  k8s-node-1
  AcquireTime:     <unset>
  RenewTime:       Wed, 05 May 2021 14:58:21 +0800
Conditions:
  Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----                 ------  -----------------                 ------------------                ------                       -------
  NetworkUnavailable   False   Wed, 05 May 2021 12:51:13 +0800   Wed, 05 May 2021 12:51:13 +0800   FlannelIsUp                  Flannel is running on this node
  MemoryPressure       False   Wed, 05 May 2021 14:56:21 +0800   Wed, 05 May 2021 12:50:48 +0800   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure         False   Wed, 05 May 2021 14:56:21 +0800   Wed, 05 May 2021 12:50:48 +0800   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure          False   Wed, 05 May 2021 14:56:21 +0800   Wed, 05 May 2021 12:50:48 +0800   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready                True    Wed, 05 May 2021 14:56:21 +0800   Wed, 05 May 2021 12:50:48 +0800   KubeletReady                 kubelet is posting ready status
Addresses:
  InternalIP:  192.168.17.131
  Hostname:    k8s-node-1
Capacity:
  cpu:                1
  ephemeral-storage:  17394Mi
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             1862992Ki
  pods:               110
Allocatable:
  cpu:                1
  ephemeral-storage:  16415037823
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             1760592Ki
  pods:               110
System Info:
  Machine ID:                 6ab2830113da4c6eabb6a7e39800eb6b
  System UUID:                6B9A4D56-D404-DC0B-087E-C3D077B94945
  Boot ID:                    719953b3-aa24-42c1-bcad-8d6aef62119a
  Kernel Version:             3.10.0-1160.25.1.el7.x86_64
  OS Image:                   CentOS Linux 7 (Core)
  Operating System:           linux
  Architecture:               amd64
  Container Runtime Version:  docker://20.10.6
  Kubelet Version:            v1.21.0
  Kube-Proxy Version:         v1.21.0
PodCIDR:                      10.244.1.0/24
PodCIDRs:                     10.244.1.0/24
Non-terminated Pods:          (4 in total)
  Namespace                   Name                                          CPU Requests  CPU Limits  Memory Requests  Memory Limits  Age
  ---------                   ----                                          ------------  ----------  ---------------  -------------  ---
  default                     nginx-deployment-784894895c-5pvll             0 (0%)        0 (0%)      0 (0%)           0 (0%)         22h
  kube-system                 kube-flannel-ds-mnzwv                         100m (10%)    100m (10%)  50Mi (2%)        50Mi (2%)      23h
  kube-system                 kube-proxy-xqhr7                              0 (0%)        0 (0%)      0 (0%)           0 (0%)         23h
  kubernetes-dashboard        dashboard-metrics-scraper-5594697f48-gn9c8    0 (0%)        0 (0%)      0 (0%)           0 (0%)         23h
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource           Requests    Limits
  --------           --------    ------
  cpu                100m (10%)  100m (10%)
  memory             50Mi (2%)   50Mi (2%)
  ephemeral-storage  0 (0%)      0 (0%)
  hugepages-1Gi      0 (0%)      0 (0%)
  hugepages-2Mi      0 (0%)      0 (0%)
Events:              <none>

查看kubelet配置信息

[root@k8s-master-1 ~]# kubectl config view
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: https://192.168.17.130:6443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: kubernetes-admin
  name: kubernetes-admin@kubernetes
current-context: kubernetes-admin@kubernetes
kind: Config
preferences: {}
users:
- name: kubernetes-admin
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

查看config(kubeadm)

[root@k8s-master-1 ~]# kubeadm config view
Command "view" is deprecated, This command is deprecated and will be removed in a future release, please use 'kubectl get cm -o yaml -n kube-system kubeadm-config' to get the kubeadm config directly.
apiServer:
  extraArgs:
    authorization-mode: Node,RBAC
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: v1.21.0
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.1.0.0/16
scheduler: {}

列出所需要的镜像列表

[root@k8s-master-1 ~]# kubeadm config images list
k8s.gcr.io/kube-apiserver:v1.21.0
k8s.gcr.io/kube-controller-manager:v1.21.0
k8s.gcr.io/kube-scheduler:v1.21.0
k8s.gcr.io/kube-proxy:v1.21.0
k8s.gcr.io/pause:3.4.1
k8s.gcr.io/etcd:3.4.13-0
k8s.gcr.io/coredns/coredns:v1.8.0

查看默认初始化参数配置

[root@k8s-master-1 ~]# kubeadm config print init-defaults
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 1.2.3.4
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: node
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: 1.21.0
networking:
  dnsDomain: cluster.local
  serviceSubnet: 10.96.0.0/12
scheduler: {}

查看pod的日志

1、查看指定pod的日志

kubectl logs <pod_name>
kubectl logs -f <pod_name> #类似tail -f的方式查看(tail -f 命令实时查看日志文件)

如下:

[root@k8s-master-1 ~]# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-784894895c-5pvll   1/1     Running   1          22h
nginx-deployment-784894895c-vfnp7   1/1     Running   1          22h
[root@k8s-master-1 ~]# 
[root@k8s-master-1 ~]# kubectl logs nginx-deployment-784894895c-5pvll
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: info: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
[root@k8s-master-1 ~]# 
[root@k8s-master-1 ~]# kubectl logs -f nginx-deployment-784894895c-5pvll
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: info: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up

2、查看指定pod中指定容器的日志

kubectl logs <pod_name> -c <container_name>
PS:查看Docker容器日志
docker logs <container_id>

查看pod的yaml文件

查看pod的yaml文件

kubectl get pod <pod-name> -n <ns-name> -o yaml

如下:

[root@k8s-master-1 ~]# kubectl get pod -n kube-system kube-apiserver-k8s-master-1 -o yaml
apiVersion: v1
kind: Pod
metadata:
  annotations:
    kubeadm.kubernetes.io/kube-apiserver.advertise-address.endpoint: 192.168.17.130:6443
    kubernetes.io/config.hash: 2d2c26864f05b6ee3c5b4b229e7b8fc0
    kubernetes.io/config.mirror: 2d2c26864f05b6ee3c5b4b229e7b8fc0
    kubernetes.io/config.seen: "2021-05-04T15:11:21.521769538+08:00"
    kubernetes.io/config.source: file
  creationTimestamp: "2021-05-04T07:11:22Z"
  labels:
    component: kube-apiserver
    tier: control-plane
  name: kube-apiserver-k8s-master-1
  namespace: kube-system
  ownerReferences:
  - apiVersion: v1
    controller: true
    kind: Node
    name: k8s-master-1
    uid: 3c39ab3c-7b3c-45c7-b6f6-7625dd035a11
  resourceVersion: "31039"
  uid: 923d618d-78bc-4117-8cdf-a79563827145
spec:
  containers:
  - command:
    - kube-apiserver
    - --advertise-address=192.168.17.130
    - --allow-privileged=true
    - --authorization-mode=Node,RBAC
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --enable-admission-plugins=NodeRestriction
    - --enable-bootstrap-token-auth=true
    - --etcd-cafile=/etc/kubernetes/pki/etcd/ca.crt
    - --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt
    - --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key
    - --etcd-servers=https://127.0.0.1:2379
    - --insecure-port=0
    - --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt
    - --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key
    - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
    - --proxy-client-cert-file=/etc/kubernetes/pki/front-proxy-client.crt
    - --proxy-client-key-file=/etc/kubernetes/pki/front-proxy-client.key
    - --requestheader-allowed-names=front-proxy-client
    - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt
    - --requestheader-extra-headers-prefix=X-Remote-Extra-
    - --requestheader-group-headers=X-Remote-Group
    - --requestheader-username-headers=X-Remote-User
    - --secure-port=6443
    - --service-account-issuer=https://kubernetes.default.svc.cluster.local
    - --service-account-key-file=/etc/kubernetes/pki/sa.pub
    - --service-account-signing-key-file=/etc/kubernetes/pki/sa.key
    - --service-cluster-ip-range=10.1.0.0/16
    - --tls-cert-file=/etc/kubernetes/pki/apiserver.crt
    - --tls-private-key-file=/etc/kubernetes/pki/apiserver.key
    image: k8s.gcr.io/kube-apiserver:v1.21.0
    imagePullPolicy: IfNotPresent
    livenessProbe:
      failureThreshold: 8
      httpGet:
        host: 192.168.17.130
        path: /livez
        port: 6443
        scheme: HTTPS
      initialDelaySeconds: 10
      periodSeconds: 10
      successThreshold: 1
      timeoutSeconds: 15
    name: kube-apiserver
    readinessProbe:
      failureThreshold: 3
      httpGet:
        host: 192.168.17.130
        path: /readyz
        port: 6443
        scheme: HTTPS
      periodSeconds: 1
      successThreshold: 1
      timeoutSeconds: 15
    resources:
      requests:
        cpu: 250m
    startupProbe:
      failureThreshold: 24
      httpGet:
        host: 192.168.17.130
        path: /livez
        port: 6443
        scheme: HTTPS
      initialDelaySeconds: 10
      periodSeconds: 10
      successThreshold: 1
      timeoutSeconds: 15
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /etc/ssl/certs
      name: ca-certs
      readOnly: true
    - mountPath: /etc/pki
      name: etc-pki
      readOnly: true
    - mountPath: /etc/kubernetes/pki
      name: k8s-certs
      readOnly: true
  dnsPolicy: ClusterFirst
  enableServiceLinks: true
  hostNetwork: true
  nodeName: k8s-master-1
  preemptionPolicy: PreemptLowerPriority
  priority: 2000001000
  priorityClassName: system-node-critical
  restartPolicy: Always
  schedulerName: default-scheduler
  securityContext: {}
  terminationGracePeriodSeconds: 30
  tolerations:
  - effect: NoExecute
    operator: Exists
  volumes:
  - hostPath:
      path: /etc/ssl/certs
      type: DirectoryOrCreate
    name: ca-certs
  - hostPath:
      path: /etc/pki
      type: DirectoryOrCreate
    name: etc-pki
  - hostPath:
      path: /etc/kubernetes/pki
      type: DirectoryOrCreate
    name: k8s-certs
status:
  conditions:
  - lastProbeTime: null
    lastTransitionTime: "2021-05-04T07:11:22Z"
    status: "True"
    type: Initialized
  - lastProbeTime: null
    lastTransitionTime: "2021-05-05T04:49:53Z"
    status: "True"
    type: Ready
  - lastProbeTime: null
    lastTransitionTime: "2021-05-05T04:49:53Z"
    status: "True"
    type: ContainersReady
  - lastProbeTime: null
    lastTransitionTime: "2021-05-04T07:11:22Z"
    status: "True"
    type: PodScheduled
  containerStatuses:
  - containerID: docker://777c2a1a5458c5daa3f8250df4fe8f97ac955bc11f507f5522c2eb9196cd48bd
    image: k8s.gcr.io/kube-apiserver:v1.21.0
    imageID: docker-pullable://k8s.gcr.io/kube-apiserver@sha256:828fefd9598ed865d45364d1be859c87aabfa445b03b350e3440d143bd21bca9
    lastState:
      terminated:
        containerID: docker://e1f524a825d9541b595dc7176fc1b4f1044f243522f3a79a4c30446f49a720d7
        exitCode: 255
        finishedAt: "2021-05-05T04:48:22Z"
        reason: Error
        startedAt: "2021-05-04T07:11:14Z"
    name: kube-apiserver
    ready: true
    restartCount: 2
    started: true
    state:
      running:
        startedAt: "2021-05-05T04:49:23Z"
  hostIP: 192.168.17.130
  phase: Running
  podIP: 192.168.17.130
  podIPs:
  - ip: 192.168.17.130
  qosClass: Burstable
  startTime: "2021-05-04T07:11:22Z"

登录容器

登录容器的时候需要注意到容器支持的shell是什么。

kubectl exec -it <pod-name> -n <ns-name> bash
kubectl exec -it <pod-name> -n <ns-name> sh

如下:

[root@k8s-master-1 ~]# kubectl get ns
NAME                   STATUS   AGE
default                Active   24h
kube-node-lease        Active   24h
kube-public            Active   24h
kube-system            Active   24h
kubernetes-dashboard   Active   24h

[root@k8s-master-1 ~]# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-784894895c-5pvll   1/1     Running   1          23h
nginx-deployment-784894895c-vfnp7   1/1     Running   1          23h

[root@k8s-master-1 ~]# kubectl exec -it nginx-deployment-784894895c-5pvll -n default /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@nginx-deployment-784894895c-5pvll:/# ls
bin   dev           docker-entrypoint.sh  home  lib64  mnt  proc  run   srv  tmp  var
boot  docker-entrypoint.d  etc             lib   media  opt  root  sbin  sys  usr
root@nginx-deployment-784894895c-5pvll:/# 

若登录时报如下错误,说明shell类型不对:

kubectl OCI runtime exec failed: exec failed: container_linux.go:345: starting container process ca

根据yaml创建资源

#根据 yaml 创建资源, apply 可以重复执行,create 不行
kubectl create -f pod.yaml
kubectl apply -f pod.yaml

根据yaml删除pod

#基于 pod.yaml 定义的名称删除 pod
kubectl delete -f pod.yaml

根据label删除pod和service

#删除所有包含某个 label 的pod 和 service
kubectl delete pod,svc -l name=<label-name>

删除pod

[root@k8s-master-1 ~]# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-784894895c-5pvll   1/1     Running   1          23h
nginx-deployment-784894895c-vfnp7   1/1     Running   1          23h
[root@k8s-master-1 ~]# kubectl delete pod nginx-deployment-784894895c-5pvll
pod "nginx-deployment-784894895c-5pvll" deleted
[root@k8s-master-1 ~]# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-784894895c-vfnp7   1/1     Running   1          23h

查看node或pod的资源使用率

[root@k8s-master-1 ~]# kubectl top pods
……
[root@k8s-master-1 ~]# kubectl top nodes
……

查看或编辑pod的yaml文件

#编辑pod的yaml文件
kubectl get deployment -n <ns-name>
kubectl edit depolyment <pod-name> -n <ns-name> -o yaml

如下:

[root@k8s-master-1 ~]# kubectl get deployment
NAME               READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   2/2     2            2           23h

[root@k8s-master-1 ~]# kubectl get deployment -n default
NAME               READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   2/2     2            2           23h

[root@k8s-master-1 ~]# kubectl get deployment -n kube-system
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
coredns   2/2     2            2           24h

[root@k8s-master-1 ~]# kubectl get deployment nginx-deployment -n default -o yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2021-05-04T08:23:43Z"
  generation: 1
  labels:
    k8s-app: nginx-deployment
  name: nginx-deployment
  namespace: default
  resourceVersion: "31570"
  uid: 47fe9d27-afc2-4f16-b2c0-8f8260e14710
spec:
  progressDeadlineSeconds: 600
  replicas: 2
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: nginx-deployment
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        k8s-app: nginx-deployment
      name: nginx-deployment
    spec:
      containers:
      - image: nginx:1.19.8
        imagePullPolicy: IfNotPresent
        name: nginx-deployment
        resources: {}
        securityContext:
          privileged: true
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      imagePullSecrets:
      - name: default-token-w79mr
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 2
  conditions:
  - lastTransitionTime: "2021-05-04T08:23:43Z"
    lastUpdateTime: "2021-05-04T08:24:37Z"
    message: ReplicaSet "nginx-deployment-784894895c" has successfully progressed.
    reason: NewReplicaSetAvailable
    status: "True"
    type: Progressing
  - lastTransitionTime: "2021-05-05T04:52:35Z"
    lastUpdateTime: "2021-05-05T04:52:35Z"
    message: Deployment has minimum availability.
    reason: MinimumReplicasAvailable
    status: "True"
    type: Available
  observedGeneration: 1
  readyReplicas: 2
  replicas: 2
  updatedReplicas: 2
  
  [root@k8s-master-1 ~]# kubectl edit deployment nginx-deployment -n default -o yaml

进入POD

[root@k8s-master-1 ~]# kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-784894895c-5pvll   1/1     Running   1          23h
nginx-deployment-784894895c-vfnp7   1/1     Running   1          23h

[root@k8s-master-1 ~]# kubectl exec -it nginx-deployment-784894895c-5pvll bash -n default
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@nginx-deployment-784894895c-5pvll:/# pwd
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文章名: 《K8S集群的相关使用命令》

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Last modification:June 5th, 2021 at 03:33 pm
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