语法：kubectl 【command】【type】【name】【flags】
①command：子命令，用于操作Kubernetes集群资源对象的命令，如create, delete, describe, get, apply等
②type：资源对象的类型，如pod, service, rc, deployment, node等，可以单数、复数以及简写（pod, pods, po/service,services, svc）
③name：资源对象的名称，不指定则返回所有，如get pod 会返回所有pod， get pod nginx， 只返回nginx这个pod
④flags：kubectl子命令的可选参数，例如-n 指定namespace，-s 指定apiserver的URL
示例：kubectl get pod tomcat-p9x0h
[root@k8s ~]# kubectl get pod tomcat-p9x0h
NAME READY STATUS RESTARTS AGE
tomcat-p9x0h 1/1 Running 0 1h一、资源对象类型列表
1：获取命令
kubectl explain 或 kubectl api-resources
名称 简写
componentsstatuses cs
daemonsets ds
deployment deploy
events ev
endpoints ep
horizontalpodautoscalers hpa
ingresses ing
jobs
limitranges limits
nodes no
namspaces ns
pods po
persistentvolumes pv
persistentvolumeclaims pvc
resourcequotas quota
replicationcontrollers rc
secrets
serviceaccounts sa
services svc
二、特殊用法
1：查询多个Pod信息
kubectl get pods 【pod1】【pod2】
示例：
[root@k8s ~]# kubectl get pods tomcat-p9x0h mysql-19h65
NAME READY STATUS RESTARTS AGE
tomcat-p9x0h 1/1 Running 0 1h
mysql-19h65 1/1 Running 0 2h2：同时查询pod、rc信息
kubectl get pod/pod1 rc/rc1
示例：
[root@k8s ~]# kubectl get pod/tomcat-p9x0h rc/mysql
NAME READY STATUS RESTARTS AGE
po/tomcat-p9x0h 1/1 Running 0 1h
NAME DESIRED CURRENT READY AGE
rc/mysql 1 1 1 2h3：同时创建rc、svc
kubectl create -f 【rc1.yaml】-f 【service1.yaml】
示例：
[root@k8s ~]# kubectl create -f mysql-rc.yaml -f mysql-svc.yaml
replicationcontroller "mysql" created
service "mysql" created
三、kubectl子命令
主要包括对资源的创建、删除、查看、修改、配置、运行等
1：查看所有子命令
kubectl --help
2：kubectl参数
kubectl options 可以查看支持的参数，例如--namespace指定所在namespace
3：kubectl输出格式
kubectl命令可以用多种格式对结果进行显示，输出格式通过-o参数指定：-o支持的格式有
输出格式 说明
custom-columns=<spec> 根据自定义列名进行输出，逗号分隔
custom-columns-file=<filename> 从文件中获取自定义列名进行输出
json 以JSON格式显示结果
jsonpath=<template> 输出jasonpath表达式定义的字段信息
jasonpath-file=<filename> 输出jsonpath表达式定义的字段信息，来源于文件
name 仅输出资源对象的名称
wide 输出更多信息，比如会输出node名
yaml 以yaml格式输出
2：举例
kubectl get pod -o wide
kubectl get pod -o yaml
kubectl get pod -o custom-columns=NAME:.metadata.name,RESC:.metadata.resourceVersion
kubectl get pod --sort-by=.metadata.name //按name排序
四、创建资源对象
1：根据yaml文件创建service和rc
kubectl create -f 【rc-yaml-name】 -f 【svc-yaml-name】
示例
[root@k8s ~]# kubectl create -f mysql-rc.yaml -f mysql-svc.yaml
replicationcontroller "mysql" created
service "mysql" created2：可以指定一个目录，这样可以一次性根据该目录下所有yaml或json文件定义资源
kubectl create -f 【directory】
示例
[root@k8s ~]# kubectl create -f /data/k8s-yaml-root/
replicationcontroller "mysql" created
service "mysql" created
五、查看资源对象
1：查看所有pod
kubectl get pods
示例：
[root@k8s ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
mysql-512rz 1/1 Running 0 2m
mysql-5kmht 1/1 Running 0 2m
tomcat-p9x0h 1/1 Running 0 2h2：查看rc和service
kubectl get rc,svc
示例：
[root@k8s ~]# kubectl get rc,svc
NAME DESIRED CURRENT READY AGE
rc/mysql 10 10 10 4m
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
svc/kubernetes 10.254.0.1 <none> 443/TCP 4h
svc/mysql 10.254.244.102 <none> 3306/TCP 4m
svc/tomcat 10.254.250.150 <nodes> 8080:30001/TCP 2h
六、描述资源对象
1：显示node的详细信息
kubectl describe nodes 【node-name】
示例：
[root@k8s ~]# kubectl describe nodes 127.0.0.1
Name: 127.0.0.1
Role:
Labels: beta.kubernetes.io/arch=amd64
beta.kubernetes.io/os=linux
kubernetes.io/hostname=127.0.0.1
Taints: <none>
CreationTimestamp: Fri, 29 Nov 2019 05:46:33 +0800
Phase:
Conditions:
Type Status LastHeartbeatTime LastTransitionTime Reason Message
---- ------ ----------------- ------------------ ------ -------
OutOfDisk False Fri, 29 Nov 2019 09:47:58 +0800 Fri, 29 Nov 2019 05:46:33 +0800 KubeletHasSufficientDisk kubelet has sufficient disk space available
MemoryPressure False Fri, 29 Nov 2019 09:47:58 +0800 Fri, 29 Nov 2019 05:46:33 +0800 KubeletHasSufficientMemory kubelet has sufficient memory available
DiskPressure False Fri, 29 Nov 2019 09:47:58 +0800 Fri, 29 Nov 2019 05:46:33 +0800 KubeletHasNoDiskPressure kubelet has no disk pressure
Ready True Fri, 29 Nov 2019 09:47:58 +0800 Fri, 29 Nov 2019 05:46:33 +0800 KubeletReady kubelet is posting ready status
Addresses: 127.0.0.1,127.0.0.1,127.0.0.1
Capacity:
alpha.kubernetes.io/nvidia-gpu: 0
cpu: 1
memory: 2902952Ki
pods: 110
Allocatable:
alpha.kubernetes.io/nvidia-gpu: 0
cpu: 1
memory: 2902952Ki
pods: 110
System Info:
Machine ID: c1cc26a06e9e405aa56fa81c7fcc0ca7
System UUID: 564DEF43-F784-4106-FBC8-E81C9DC9216F
Boot ID: 9df7d476-41e9-412d-bde4-9b9ba119ba25
Kernel Version: 3.10.0-123.el7.x86_64
OS Image: CentOS Linux 7 (Core)
Operating System: linux
Architecture: amd64
Container Runtime Version: docker://1.13.1
Kubelet Version: v1.5.2
Kube-Proxy Version: v1.5.2
ExternalID: 127.0.0.1
Non-terminated Pods: (11 in total)
Namespace Name CPU Requests CPU Limits Memory Requests Memory Limits
--------- ---- ------------ ---------- --------------- -------------
default mysql-05ktg 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-5tvkd 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-dccp5 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-f3195 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-h6h4h 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-hbhhl 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-hws8f 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-jt4sf 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-m8z1d 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default mysql-xkgcn 0 (0%) 0 (0%) 0 (0%) 0 (0%)
default tomcat-c5995 0 (0%) 0 (0%) 0 (0%) 0 (0%)
Allocated resources:
(Total limits may be over 100 percent, i.e., overcommitted.
CPU Requests CPU Limits Memory Requests Memory Limits
------------ ---------- --------------- -------------
0 (0%) 0 (0%) 0 (0%) 0 (0%)
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
32m 32m 1 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-vgtbf_default(ae73965a-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-twqs3_default(ae73c4c4-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-x61sl_default(ae7378c1-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-5kmht_default(ae7440a0-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 1 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-rp3pz_default(ae744a31-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-8znqq_default(ae73a01f-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-512rz_default(ae7386c6-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-6vf6j_default(ae73b850-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-cwmlr_default(ae73a8e3-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 32m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-8739b_default(ae73b0a3-1245-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
28m 28m 1 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-j8s9g_default(3708c328-1246-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
28m 28m 1 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-rlprq_default(376b8d4e-1246-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-hbhhl_default(b0441080-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-dccp5_default(b043a874-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-05ktg_default(b0442004-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-hws8f_default(b0441a6c-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-xkgcn_default(b04429a8-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-jt4sf_default(b0508921-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-f3195_default(b0759f67-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-5tvkd_default(b0e0a048-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
4m 4m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "mysql-m8z1d_default(b0c00ce6-1249-11ea-ac12-000c29c9216f)". Falling back to DNSDefault policy.
32m 4m 24 {kubelet 127.0.0.1}
2：显示pod的详细信息
kubectl describe pods【pod-name】
示例：
[root@k8s ~]# kubectl describe pods mysql-f3195
Name: mysql-f3195
Namespace: default
Node: 127.0.0.1/127.0.0.1
Start Time: Fri, 29 Nov 2019 09:43:49 +0800
Labels: app=mysql
Status: Running
IP: 172.17.0.4
Controllers: ReplicationController/mysql
Containers:
mysql:
Container ID: docker://25d5f66e45a3650e8dc054ab3644f73a726b008d2160c8496d72a09832242662
Image: mysql:5.6
Image ID: docker-pullable://docker.io/mysql@sha256:5345afaaf1712e60bbc4d9ef32cc62acf41e4160584142f8d73115f16ad94af4
Port: 3306/TCP
State: Running
Started: Fri, 29 Nov 2019 09:44:03 +0800
Ready: True
Restart Count: 0
Volume Mounts: <none>
Environment Variables:
MYSQL_ROOT_PASSWORD: 123456
Conditions:
Type Status
Initialized True
Ready True
PodScheduled True
No volumes.
QoS Class: BestEffort
Tolerations: <none>
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
3m 3m 1 {default-scheduler } Normal Scheduled Successfully assigned mysql-f3195 to 127.0.0.1
3m 3m 2 {kubelet 127.0.0.1} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
3m 3m 1 {kubelet 127.0.0.1} spec.containers{mysql} Normal Pulled Container image "mysql:5.6" already present on machine
3m 3m 1 {kubelet 127.0.0.1} spec.containers{mysql} Normal Created Created container with docker id 25d5f66e45a3; Security:[seccomp=unconfined]
3m 3m 1 {kubelet 127.0.0.1} spec.containers{mysql} Normal Started Started container with docker id 25d5f66e45a33：显示deployment管理的pod信息
kubectl describe pods 【deployment-name】
七、删除资源对象
1：基于yaml文件删除，-f指定文件
kubectl delete -f 【pod.yaml】
示例：
[root@k8s ~]# kubectl delete -f mysql-rc.yaml
replicationcontroller "mysql" deleted
[root@k8s ~]# kubectl get rc
NAME DESIRED CURRENT READY AGE
tomcat 1 1 1 2h2：删除所有包含某个label的pod和service
kubectl delete po,svc -l name=【lable-name】
示例：
[root@k8s ~]# kubectl delete po,svc -l app=mysql
pod "mysql-0f7b6" deleted
pod "mysql-0fs9s" deleted
pod "mysql-1zmvc" deleted
pod "mysql-9d6vk" deleted
pod "mysql-gbtvh" deleted3：删除所有pod
kubectl delete pods --all
示例：
[root@k8s ~]# kubectl delete pods --all
pod "mysql-512rz" deleted
pod "mysql-5kmht" deleted
pod "tomcat-p9x0h" deleted
八、执行容器的命令
1：指定pod的某个容器执行命令
kubectl exec 【pod-name】 uname
示例：
[root@k8s ~]# kubectl exec mysql-0f7b6 uname
Linux2：进入到pod的容器里
kubectl exec-it 【pod-name】 bash
示例：
[root@k8s ~]# kubectl exec -it mysql-0f7b6 bash
root@mysql-0f7b6:/# ls
bin boot dev docker-entrypoint-initdb.d entrypoint.sh etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
九、查看日志命令
1：查看某个容器日志
kubectl logs 【pod-name】
示例：
[root@k8s ~]# kubectl logs mysql-0f7b6
2019-11-29 01:19:10+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.6.46-1debian9 started.
2019-11-29 01:19:10+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2019-11-29 01:19:10+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.6.46-1debian9 started.
2019-11-29 01:19:10+00:00 [Note] [Entrypoint]: Initializing database files
2019-11-29 01:19:11 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-11-29 01:19:11 0 [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
2019-11-29 01:19:11 0 [Note] /usr/sbin/mysqld (mysqld 5.6.46) starting as process 47 ...
2019-11-29 01:19:11 47 [Note] InnoDB: Using atomics to ref count buffer pool pages2：动态查看日志，类似于tail-f
kubectl logs -f 【pod-name】
示例：
[root@k8s ~]# kubectl logs -f mysql-0f7b6
2019-11-29 01:20:40 1 [Warning] 'proxies_priv' entry '@ root@mysql-0f7b6' ignored in --skip-name-resolve mode.
2019-11-29 01:20:41 1 [Note] Event Scheduler: Loaded 0 events
2019-11-29 01:20:41 1 [Note] mysqld: ready for connections.
Version: '5.6.46' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)记录每一天有趣的事情！！
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