kubectl作為我們主要的操作K8S的工具，其具備非常豐富的功能，但是如果不經過打磨，使用起來還是存在諸多不便，今天我們來看看如何將我們的kubectl打磨的更加易用。
一、命令自動補全
kubectl中提供非常多的命令，如果每一次都要手動一個字元一個字元的敲未免太累了，那麼如何配置自動補全呢？這裡以ubuntu系統為例：
1、安裝auto-completion工具
$ sudo apt update Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease Hit:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease Hit:4 https://download.docker.com/linux/ubuntu bionic InRelease Hit:5 http://archive.ubuntu.com/ubuntu bionic-backports InRelease Reading package lists... Done Building dependency tree Reading state information... Done 144 packages can be upgraded. Run 'apt list --upgradable' to see them. $ sudo apt install bash-completion Reading package lists... Done Building dependency tree Reading state information... Done bash-completion is already the newest version (1:2.8-1ubuntu1). 0 upgraded, 0 newly installed, 0 to remove and 144 not upgraded.
PS：如果是centos系統，則使用yum install bash-completion -y命令安裝
2、配置自動補全
Bash：
source <(kubectl completion bash) echo "source <(kubectl completion bash)" >> ~/.bashrc
Zsh：
source <(kubectl completion zsh) echo "[[ $commands[kubectl] ]] && source <(kubectl completion zsh)" >> ~/.zshrc
配置後就可以通過Tab鍵自動補全命令啦！
二、配置kubectl別名
我們可以通過設定別名簡化kubectl命令，編輯.bashrc檔案，新增如下內容：
alias sudo='sudo ' alias k='kubectl' alias ka='kubectl apply --recursive -f' alias kex='kubectl exec -i -t' alias klo='kubectl logs -f' alias kg='kubectl get' alias kd='kubectl describe'
PS：alias sudo是為了解決sudo下別名不可用問題
儲存後記得執行 source ~/.bashrc哈，接著我們體驗下：
$ sudo ka webapp_pod.yaml pod/webapp created $ sudo kg pods NAME READY STATUS RESTARTS AGE webapp 0/2 ContainerCreating 0 7s $ sudo kd pod webapp Name: webapp Namespace: default Priority: 0 Node: ayato/172.16.194.135 Start Time: Wed, 09 Feb 2022 14:04:44 +0000 Labels: app=webapp Annotations: <none> Status: Running IP: 172.17.0.6 IPs: IP: 172.17.0.6 Containers: webapp: Container ID: docker://d9ddf9dd47de12b53f2119bf75df6706bee2e7711509638ad52adc9addeda704 Image: 172.16.194.135:5000/webapp:1.0 Image ID: docker-pullable://172.16.194.135:5000/webapp@sha256:df3a447a013ada0642dec67bb31976f42f1a0699a68873d0452f514fa24e5c77 Port: 5000/TCP Host Port: 0/TCP State: Running Started: Wed, 09 Feb 2022 14:04:46 +0000 Ready: True Restart Count: 0 Environment: <none> Mounts: /tmp from webapp-logs (rw) /var/run/secrets/kubernetes.io/serviceaccount from default-token-pcr2h (ro) busybox: Container ID: docker://6a6a35a628a782fc643af3dd49986bbc77c23de1ae4726bc521c77f61abbbf5d Image: busybox Image ID: docker-pullable://busybox@sha256:afcc7f1ac1b49db317a7196c902e61c6c3c4607d63599ee1a82d702d249a0ccb Port: <none> Host Port: <none> Command: sh -c tail -f /logs/log.out State: Running Started: Wed, 09 Feb 2022 14:06:53 +0000 Ready: True Restart Count: 0 Environment: <none> Mounts: /logs from webapp-logs (rw) /var/run/secrets/kubernetes.io/serviceaccount from default-token-pcr2h (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: webapp-logs: Type: EmptyDir (a temporary directory that shares a pod's lifetime) Medium: SizeLimit: <unset> default-token-pcr2h: Type: Secret (a volume populated by a Secret) SecretName: default-token-pcr2h Optional: false QoS Class: BestEffort Node-Selectors: <none> Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s node.kubernetes.io/unreachable:NoExecute op=Exists for 300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 2m23s default-scheduler Successfully assigned default/webapp to ayato Normal Pulled 2m22s kubelet Container image "172.16.194.135:5000/webapp:1.0" already present on machine Normal Created 2m21s kubelet Created container webapp Normal Started 2m21s kubelet Started container webapp Normal Pulling 2m21s kubelet Pulling image "busybox" Normal Pulled 15s kubelet Successfully pulled image "busybox" in 14.633078305s Normal Created 15s kubelet Created container busybox Normal Started 14s kubelet Started container busybox
真的是飛一般的感覺！！！
三、Context和Namespace切換
我們在公司的容器平臺上使用kubectl時，經常需要切換context和namespace，導致命令非常繁瑣，那有沒有簡便的方式呢？—— kubectx
kubectx安裝
$ sudo git clone https://github.com/ahmetb/kubectx /opt/kubectx Cloning into '/opt/kubectx'... remote: Enumerating objects: 1457, done. remote: Counting objects: 100% (172/172), done. remote: Compressing objects: 100% (115/115), done. remote: Total 1457 (delta 85), reused 97 (delta 51), pack-reused 1285 Receiving objects: 100% (1457/1457), 905.30 KiB | 69.00 KiB/s, done. Resolving deltas: 100% (817/817), done. $ sudo ln -s /opt/kubectx/kubens /usr/local/bin/kubectl-ns $ sudo ln -s /opt/kubectx/kubectx /usr/local/bin/kubectl-ctx
我們來看一下效果：
$ sudo k ctx minikube $ sudo k ctx minikube Switched to context "minikube". $ sudo k ns default kube-node-lease kube-public kube-system kubernetes-dashboard $ sudo k ns kube-public Context "minikube" modified. Active namespace is "kube-public". $ sudo k ns default Context "minikube" modified. Active namespace is "default".
四、跟蹤檢視多個Pod的日誌
我們一般使用kubectl logs命令檢視Pod日誌，但是它不能通過-f引數同時跟蹤檢視多個Pod日誌，這就不方便了，畢竟實際生產環境中每個服務都會有多個Pod，這時我們可以使用stern這個工具，它具備如下能力：
-
允許使用正規表示式來選擇需要檢視的PodName
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為不同 Pod 的日誌展示不同的顏色
-
跟蹤日誌過程中假如有符合規則的新 Pod 被建立, 那麼會自動新增到輸出中
首先安裝stern（下載stern時可能較慢可以多試幾次）：
wget https://github.com/wercker/stern/releases/download/1.11.0/stern_linux_amd64 sudo mv stern_linux_amd64 /usr/local/bin/kubectl-tail sudo chomd +x /usr/local/bin/kubectl-tail
安裝完畢後讓我一起感受一下stern的魅力吧，我的Pod裡面有兩個容器：webapp和busybox，如果使用kubectl logs 還得指定具體的容器，而使用stern就沒有這樣的限制。
$ sudo k tail . + webapp › busybox + webapp › webapp webapp busybox 14:04:53.197 [INFO ] [main] [org.apache.coyote.http11.Http11NioProtocol] Initializing ProtocolHandler ["http-nio-4567"] webapp busybox 14:04:53.200 [INFO ] [main] [org.apache.catalina.core.StandardService] Starting service [Tomcat] webapp busybox 14:04:53.201 [INFO ] [main] [org.apache.catalina.core.StandardEngine] Starting Servlet engine: [Apache Tomcat/9.0.41] webapp busybox 14:04:53.324 [INFO ] [main] [org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/]] Initializing Spring embedded WebApplicationContext webapp busybox 14:04:53.325 [INFO ] [main] [org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext] Root WebApplicationContext: initialization completed in 2952 ms webapp busybox 14:04:53.801 [INFO ] [main] [org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor] Initializing ExecutorService 'applicationTaskExecutor' webapp busybox 14:04:54.264 [WARN ] [main] [org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$DefaultTemplateResolverConfiguration] Cannot find template location: classpath:/templates/ (please add some templates or check your Thymeleaf configuration) webapp busybox 14:04:54.377 [INFO ] [main] [org.apache.coyote.http11.Http11NioProtocol] Starting ProtocolHandler ["http-nio-4567"] webapp busybox 14:04:54.481 [INFO ] [main] [org.springframework.boot.web.embedded.tomcat.TomcatWebServer] Tomcat started on port(s): 4567 (http) with context path '' webapp busybox 14:04:54.509 [INFO ] [main] [org.demo.webapp.todolist.TodoListApplication] Started TodoListApplication in 6.235 seconds (JVM running for 8.074) webapp webapp webapp webapp . ____ _ __ _ _ webapp webapp /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ webapp webapp ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ webapp webapp \\/ ___)| |_)| | | | | || (_| | ) ) ) ) webapp webapp ' |____| .__|_| |_|_| |_\__, | / / / / webapp webapp =========|_|==============|___/=/_/_/_/ webapp webapp :: Spring Boot :: (v2.4.2) webapp webapp webapp webapp 14:04:50.124 [INFO ] [main] [org.demo.webapp.todolist.TodoListApplication] Starting TodoListApplication v1.0-SNAPSHOT using Java 1.8.0_111 on webapp with PID 1 (/opt/soft/webapp.jar started by root in /opt/soft) webapp webapp 14:04:50.165 [INFO ] [main] [org.demo.webapp.todolist.TodoListApplication] No active profile set, falling back to default profiles: default webapp webapp 14:04:53.158 [INFO ] [main] [org.springframework.boot.web.embedded.tomcat.TomcatWebServer] Tomcat initialized with port(s): 4567 (http) webapp webapp 14:04:53.197 [INFO ] [main] [org.apache.coyote.http11.Http11NioProtocol] Initializing ProtocolHandler ["http-nio-4567"] webapp webapp 14:04:53.200 [INFO ] [main] [org.apache.catalina.core.StandardService] Starting service [Tomcat] webapp webapp 14:04:53.201 [INFO ] [main] [org.apache.catalina.core.StandardEngine] Starting Servlet engine: [Apache Tomcat/9.0.41] webapp webapp 14:04:53.324 [INFO ] [main] [org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/]] Initializing Spring embedded WebApplicationContext webapp webapp 14:04:53.325 [INFO ] [main] [org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext] Root WebApplicationContext: initialization completed in 2952 ms webapp webapp 14:04:53.801 [INFO ] [main] [org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor] Initializing ExecutorService 'applicationTaskExecutor' webapp webapp 14:04:54.264 [WARN ] [main] [org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$DefaultTemplateResolverConfiguration] Cannot find template location: classpath:/templates/ (please add some templates or check your Thymeleaf configuration) webapp webapp 14:04:54.377 [INFO ] [main] [org.apache.coyote.http11.Http11NioProtocol] Starting ProtocolHandler ["http-nio-4567"] webapp webapp 14:04:54.481 [INFO ] [main] [org.springframework.boot.web.embedded.tomcat.TomcatWebServer] Tomcat started on port(s): 4567 (http) with context path '' webapp webapp 14:04:54.509 [INFO ] [main] [org.demo.webapp.todolist.TodoListApplication] Started TodoListApplication in 6.235 seconds (JVM running for 8.074)