有关基础查看、排查和操作的命令，除web ui以外，完全可以通过kubectl命令。 可以通过kubectl –help 进行，或者自命令 比如kubectl create –help查看，命令操作基本还是要多用多看帮助就熟练了。
这里记录一下常用的一些查看和操作的命令，部分做了中文翻译，不过还是建议看英文。
Basic Commands (Beginner):
create 从文件或stdin创建资源
expose 为deployment，pod创建Service。
run Run a particular image on the cluster 老版本在用，未来会被弃用，官方建议使用create 参数较多，可以考了 kubectl run –help查看
set 更新resource ,比如更新env环境变量，image，resources 资源限制，selector subject等。
Basic Commands (Intermediate):
get 最基本的对象查询命令。如 kubectl get nodes/pods/deploy/rs/ns/secret等等， 加-o wide查看详细信息，-o yaml 或-o json 输出具体格式。
explain 查看资源定义（文档）。如 kubectl explain replicaset
edit 使用系统编辑器编辑资源，完成对象的更新。如 kubectl edit deploy/foo
delete 删除指定资源，支持文件名、资源名、label selector。
Deploy Commands:
rollout Deployment, Daemonset的升级过程管理（查看状态status、操作历史history、暂停升级、恢复升级、回滚等）
scale 修改Deployment, ReplicaSet, ReplicationController, Job的实例数,实现一个副本集的手工扩展。
autoscale 为Deploy, RS, RC配置自动伸缩规则（依赖heapster和hpa）
Cluster Management Commands:
certificate Modify certificate resources.
cluster-info 查看集群信息
top 查看资源占用率（依赖heapster）
cordon 标记节点为unschedulable
uncordon 标记节点为schedulable
drain 驱逐节点上的应用，准备下线维护
taint 修改节点taint标记
Troubleshooting and Debugging Commands（故障排查和调试命令）:
describe 查看资源详情
logs 查看pod内容器的日志
attach Attach到pod内的一个容器
exec 在指定容器内执行命令
port-forward 为pod创建本地端口映射
proxy 为Kubernetes API server创建代理
cp 容器内外/容器间文件拷贝
auth Inspect authorization
Advanced Commands:
apply 从文件或stdin创建/更新资源
patch 使用strategic merge patch语法更新对象的某些字段
replace 从文件或stdin更新资源
convert 在不同API版本之间转换对象定义
Settings Commands:
label 给资源设置label
annotate 给资源设置annotation
completion 获取shell自动补全脚本(支持bash和zsh)
Other Commands:
api-versions Print the supported API versions on the server, in the form of “group/version”
api-resources Print the supported API resources on the server
config 修改kubectl配置（kubeconfig文件），如context
help Help about any command
version 查看客户端和Server端K8S版本
一，kubectl实用技巧（网上找到的）
1，查看资源缩写
kubectl describe 或者 kubectl api-resources
2，配置kubectl自动完成
source < (kubectl completion bash)
3，kubectl写yaml太累，找样例太麻烦?
用run命令生成
kubectl run --image=nginx my-deploy -o yaml --dry-run > my-deploy.yaml
4，用get命令导出
kubectl get statefulset/foo -o=yaml --export > new.yaml
二，常用查看和故障排查命令
1，检查集群是否正常
[root@master01 ~]# kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-1 Healthy {"health": "true"}
etcd-0 Healthy {"health": "true"}
etcd-2 Healthy {"health": "true"}
如果某一个不正常，请查看对应日志。比如etcd集群时不时提示unhealthy，请查看etcd节点日志信息，假如系统负载过高，会导致心跳检测失败。
2，检查master状态是否正常
[root@master01 ~] kubectl cluster-info Kubernetes master is running at https://10.1.14.21:6443 Heapster is running at https://10.1.14.25:6443/api/v1/namespaces/kube-system/services/heapster/proxy KubeDNS is running at https://10.1.14.25:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy monitoring-grafana is running at https://10.1.14.21:6443/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy monitoring-influxdb is running at https://192.168.20.134:6443/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy
3,通过kubectl run 创建一组pods nginx，这个命令会启动创建deploy 以及rs 。 这里以nginx1.10为例进行演示
kubectl run nginx --image=nginx:1.10 --port=80 --labels="app=nginx1.10" --replicas=2
查看执行结果：
[root@master01 yaml]# kubectl get pods NAME READY STATUS RESTARTS AGE nginx-64f9d8b667-grtql 0/1 ContainerCreating 0 50s nginx-64f9d8b667-vbhkh 0/1 ContainerCreating 0 49s
这里一般会配合dscribe 命令查看pods创建状态，可以看到每个pod分配到哪个node以及进度；如果失败，会记录失败原因。
4，kubectl get
查看resource资源，比如常用的nodes/pods/replicasets/services/endpoints/deployments/namespaces等等
使用kubectl get xxx ,如果要查看详细输出，后边可以加-o wide参数； -o yaml 或-o json 输出具体格式。 。
[root@master01 ~]# kubectl get pods -n kube-system -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE kube-dns-79fbb66f55-5xvlq 3/3 Running 3 21h 172.50.70.5 10.1.14.25
5，kubectl describe xxx
支持多数resources，比如node/pod/ns/deployment/rs/rc/svc等等
获取resource的详细信息，一般用于资源的详细参数，pods 无法正常启动的排查，查看报错日志，比如images pull失败，加载参数报错等等。
这里简单记录下刚才创建pod：
[root@master01 yaml]# kubectl describe pods nginx-64f9d8b667-grtql
Name: nginx-64f9d8b667-grtql
Namespace: default
Node: 10.1.14.26/10.1.14.26
Start Time: Wed, 28 Nov 2017 23:20:18 -0500
Labels: app=nginx1.10
pod-template-hash=64f9d8b667
Annotations:
Status: Pending
IP:
Controlled By: ReplicaSet/nginx-64f9d8b667
Containers:
nginx:
Container ID:
Image: nginx:1.10
Image ID:
Port: 80/TCP
Host Port: 0/TCP
State: Waiting
Reason: ContainerCreating
Ready: False
Restart Count: 0
Environment:
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-bzjbz (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
default-token-bzjbz:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-bzjbz
Optional: false
QoS Class: BestEffort
Node-Selectors:
Tolerations:
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 17s default-scheduler Successfully assigned default/nginx-64f9d8b667-grtql to 10.1.14.26
Normal Pulling 11s kubelet, 10.1.14.26 pulling image "nginx:1.10"
可以看到pod nginx-64f9d8b667-grtql被kube-scheduler分配到了node 10.1.14.26节点，目前正在pull nginx:1.10的镜像。如完成会提示创建成功和启动成功。
6,在pod或容器中执行命令 kubectl exec用法
执行Pod的data命令，默认是用Pod中的第一个容器执行
kubectl exec pods名称 command
指定Pod中某个容器执行data命令
kubectl exec pods名称 command
比如：
[root@master01 yaml]# kubectl exec nginx-64f9d8b667-grtql cat /etc/hosts # Kubernetes-managed hosts file. 127.0.0.1 localhost ::1 localhost ip6-localhost ip6-loopback fe00::0 ip6-localnet fe00::0 ip6-mcastprefix fe00::1 ip6-allnodes fe00::2 ip6-allrouters 172.50.75.2 nginx-64f9d8b667-grtql
通过bash获得Pod中某个容器的TTY，相当于登录容器
kubectl exec -it pods名称 bash
例子如下：
[root@master01 yaml]# kubectl exec -ti nginx-64f9d8b667-grtql bash root@nginx-64f9d8b667-grtql:/# cat /etc/hosts # Kubernetes-managed hosts file. 127.0.0.1 localhost ::1 localhost ip6-localhost ip6-loopback fe00::0 ip6-localnet fe00::0 ip6-mcastprefix fe00::1 ip6-allnodes fe00::2 ip6-allrouters 172.50.75.2 nginx-64f9d8b667-grtql
7，kubectl logs
使用kubectl logs能够取出pod中镜像的log，也是故障排除时候的重要信息
[root@master01 yaml]# kubectl logs nginx-dbddb74b8-7pwk2 10.254.143.54 - - [28/Nov/2017:03:19:43 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.29.0" "-" 172.50.75.1 - - [28/Nov/2017:03:23:12 +0000] "GET / HTTP/1.1" 200 612 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36" "-" 2017/11/28 03:23:13 [error] 7#7: *3 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 172.50.75.1, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "10.1.14.26:30765", referrer: "http://10.1.14.26:30765/"
8，kubectl expose 创建svc进行端口报漏，方便外部访问。
kubectl expose deploy nginx --port=80 --target-port=80 --type=NodePort --name=nginx-service
查看svc：
[root@master01 yaml]# kubectl get svc -o wide NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR kubernetes ClusterIP 10.254.0.1 443/TCP 16d nginx-service NodePort 10.254.218.227 80:30680/TCP 119s app=nginx1.10 [root@master01 yaml]# kubectl describe svc nginx-service Name: nginx-service Namespace: default Labels: app=nginx1.10 Annotations: Selector: app=nginx1.10 Type: NodePort IP: 10.254.218.227 Port: 80/TCP TargetPort: 80/TCP NodePort: 30680/TCP Endpoints: 172.50.70.4:80,172.50.75.2:80 Session Affinity: None External Traffic Policy: Cluster Events:
访问测试效果：
[root@node01 ~]# curl -I 10.254.218.227:80 HTTP/1.1 200 OK Server: nginx/1.10.3 Date: Thu, 29 Nov 2017 04:40:48 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Tue, 31 Jan 2017 15:01:11 GMT Connection: keep-alive ETag: "5890a6b7-264" Accept-Ranges: bytes [root@node01 ~]# curl -I 10.1.14.25:30680 HTTP/1.1 200 OK Server: nginx/1.10.3 Date: Thu, 29 Nov 2017 04:41:30 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Tue, 31 Jan 2017 15:01:11 GMT Connection: keep-alive ETag: "5890a6b7-264" Accept-Ranges: bytes
9，kubectl set或者 kubectl edit 进行pod模版的版本更新,大到环境image更新，小到pod模版的env 设置，request resource资源限制，selector设置，sa 或者subject修改。
比如，我们更新image ，由之前nginx=nginx:1.10更新到nginx:1.11，分别采用kubectl set 或者kubectl edit测试
（1）kubectl set ，具体用法可以kubectl set –help了解：
kubectl set image deploy/nginx nginx=nginx:1.11
重新访问，发现nginx的响应头信息已经变成nginx1.11
（2）kubecctl edit 编辑deploy
kubectl edit deploy/nginx
进去直接编辑image的镜像版本信息，保存后保存。依然可以实现指定pod image的更新。
10,kubectl rollout 查看版本发布情况以及历史版本信息 以及回滚操作
（1）kubectl rollout status 查看版本发布情况：
[root@master01 ~]# kubectl rollout status deploy/nginx Waiting for deployment "nginx" rollout to finish: 1 out of 2 new replicas have been updated... Waiting for deployment "nginx" rollout to finish: 1 out of 2 new replicas have been updated... Waiting for deployment "nginx" rollout to finish: 1 out of 2 new replicas have been updated... Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination... Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination... deployment "nginx" successfully rolled out
（2）kubectl rollout history 查看版本发布历史，加–revision=x（x为版本号）可以查看具体细节
[root@master01 ~]# kubectl rollout history deploy/nginx
deployment.extensions/nginx
REVISION CHANGE-CAUSE
2
3
4 kubectl set image deploy/nginx nginx=nginx:1.13 --record=true
[root@master01 ~]# kubectl rollout history deploy/nginx --revision=2
deployment.extensions/nginx with revision #2
Pod Template:
Labels: app=nginx1.10
pod-template-hash=d99665758
Containers:
nginx:
Image: nginx:1.11
Port: 80/TCP
Host Port: 0/TCP
Environment:
Mounts:
Volumes:
(3)kubectl rollout undo 撤回上一个版本，–to-revision=x回退到指定版本
kubectl rollout undo deployment nginx #回滚到上一个版本 kubectl rollout undo deployment nginx --to-revision=2 #回滚到指定版本
（4）另外kubectl rollout pause/resume 暂停和恢复升级这里不与演示，操作差不多
11，kubectl scale 扩展deploy ,适用于手工扩展deploy情况。
[root@master01 ~]# kubectl scale deploy nginx --replicas=4 deployment.extensions/nginx scaled [root@master01 ~]# kubectl get pods -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE nginx-d99665758-5pm47 0/1 Pending 0 1s 10.1.14.25 nginx-d99665758-qqhhx 1/1 Running 0 2m42s 172.50.51.3 10.1.14.26 nginx-d99665758-tppvb 0/1 Pending 0 2s 10.1.14.25 nginx-d99665758-z5dhz 1/1 Running 0 2m51s 172.50.51.2 10.1.14.26
转载请注明：21运维 » kubenetes 集群常用查看和故障排查命令（持续更新）