kubernetes环境中kubectl自动补全

在使用kubernetes中，利用kubectl来管理kubernetes的应用，有时候在敲命令的时候会涉及到命令的自动补全，这个就像linux的命令补全一样，命令有很多，如果没有命令补全会在使用的过程中出现命令忘记，命令不知道如何使用的情况，而且不通的环境命令的格式不一样，所以需要使用命令补全来解决。

先说一下我的环境，我的mac环境是使用的item2终端，用的zsh，所以我的配置需要添加到zsh中才能生效，不过前提是已经安装好了kubectl命令，下面是几种环境安装kubectl的方法：

Ubuntu环境

[wolf@wulaoer.org ~]$ sudo apt-get update && sudo apt-get install -y apt-transport-https
[wolf@wulaoer.org ~]$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
[wolf@wulaoer.org ~]$ echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list
[wolf@wulaoer.org ~]$ sudo apt-get update
[wolf@wulaoer.org ~]$ sudo apt-get install -y kubectl

Centos环境

[wolf@wulaoer.org ~]$ cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
[wolf@wulaoer.org ~]$ yum install -y kubectl

mac环境

[wolf@wulaoer.org ~]$ brew install kubernetes-cli
[wolf@wulaoer.org ~]$ kubectl version --client

以上是各种环境安装kubectl的方法，可以根据自己的环境选择适合自己的方式安装，如果已经安装好了kubectl，就可以设置kubectl自动补全了。

mac kubectl自动补全

先看一下mac环境的kubectl的自动补全，我已经安装好了kubectl，如果没有安装可以参考一下上面的方式，如果没有brew可以参考：https://brew.sh/

[wolf@wulaoer.org ~]$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

安装之后，看一下kubectl的帮助：

[wolf@wulaoer.org ~]$ kubectl completion --help
Output shell completion code for the specified shell (bash or zsh). The shell code must be evaluated to provide
interactive completion of kubectl commands.  This can be done by sourcing it from the .bash_profile.

 Detailed instructions on how to do this are available here:
https://kubernetes.io/docs/tasks/tools/install-kubectl/#enabling-shell-autocompletion

 Note for zsh users: [1] zsh completions are only supported in versions of zsh >= 5.2

Examples:
  # Installing bash completion on macOS using homebrew
  ## If running Bash 3.2 included with macOS
  brew install bash-completion
  ## or, if running Bash 4.1+
  brew install bash-completion@2
  ## If kubectl is installed via homebrew, this should start working immediately.
  ## If you've installed via other means, you may need add the completion to your completion directory
  kubectl completion bash > $(brew --prefix)/etc/bash_completion.d/kubectl


  # Installing bash completion on Linux
  ## If bash-completion is not installed on Linux, please install the 'bash-completion' package
  ## via your distribution's package manager.
  ## Load the kubectl completion code for bash into the current shell
  source <(kubectl completion bash)
  ## Write bash completion code to a file and source if from .bash_profile
  kubectl completion bash > ~/.kube/completion.bash.inc
  printf "
  # Kubectl shell completion
  source '$HOME/.kube/completion.bash.inc'
  " >> $HOME/.bash_profile
  source $HOME/.bash_profile

  # Load the kubectl completion code for zsh[1] into the current shell
  source <(kubectl completion zsh)
  # Set the kubectl completion code for zsh[1] to autoload on startup
  kubectl completion zsh > "${fpath[1]}/_kubectl"

Usage:
  kubectl completion SHELL [options]

Use "kubectl options" for a list of global command-line options (applies to all commands).

根据上面的提示可以看到3.2版本的使用brew install bash-completion，如果大于4.1版本可以使用brew install bash-completion@2看一下我的bash的版本：

[wolf@wulaoer.org ~]$ /bin/bash --version
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin19)
Copyright (C) 2007 Free Software Foundation, Inc.

我的是3.2版本的，所以选择第一种方式安装，

[wolf@wulaoer.org ~]$ brew install bash-completion

因为涉及到国外的网站下载，所以需要做一下本地解析：

[wolf@wulaoer.org ~]$ cat /etc/hosts
................................
199.232.28.133    raw.githubusercontent.com

把kubectl completion bash 增加到你的completion 目录：

[wolf@wulaoer.org ~]$ kubectl completion bash > $(brew --prefix)/etc/bash_completion.d/kubectl

调用brew info命令，根据提示将指令添加到~/.bash_profile中：

[wolf@wulaoer.org ~]$ brew info bash-completion
bash-completion: stable 1.3 (bottled)
Programmable completion for Bash 3.2
https://salsa.debian.org/debian/bash-completion
Conflicts with:
  bash-completion@2 (because each are different versions of the same formula)
/usr/local/Cellar/bash-completion/1.3_3 (189 files, 607.9KB) *
  Poured from bottle on 2020-08-13 at 14:28:23
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/bash-completion.rb
==> Caveats
Add the following line to your ~/.bash_profile:
  [[ -r "/usr/local/etc/profile.d/bash_completion.sh" ]] && . "/usr/local/etc/profile.d/bash_completion.sh"

Bash completion has been installed to:
  /usr/local/etc/bash_completion.d
==> Analytics
install: 9,475 (30 days), 29,898 (90 days), 151,703 (365 days)
install-on-request: 8,820 (30 days), 27,651 (90 days), 140,266 (365 days)
build-error: 0 (30 days)

根据上面的提示，把[[ -r "/usr/local/etc/profile.d/bash_completion.sh" ]] && . "/usr/local/etc/profile.d/bash_completion.sh"添加到~/.bash_profile中，然后设置zsh

[wolf@wulaoer.org ~]$ source <(kubectl completion zsh)
[wolf@wulaoer.org ~]$ echo "source <(kubectl completion zsh)" >> ~/.zshrc
[wolf@wulaoer.org ~]$ source ~/.zshrc

重新打开终端即可。

Centos环境kubectl自动补全

[wolf@wulaoer.org ~]# yum install bash-completion -y

[wolf@wulaoer.org ~]# echo "source <(kubectl completion bash)" >> ~/.bashrc

[wolf@wulaoer.org ~]# source ~/.bashrc

[wolf@wulaoer.org ~]# source /usr/share/bash-completion/bash_completion
[wolf@wulaoer.org ~]# source <(kubectl completion bash)

Ubuntu环境kubectl自动补全

[wolf@wulaoer.org ~]$ apt install bash-completion
// locate bash_completion
[wolf@wulaoer.org ~]$ source /usr/share/bash-completion/bash_completion
[wolf@wulaoer.org ~]$ source <(kubectl completion bash)

以上是三个环境的kubectl的自动补全方法，kubectl能够自动补全会起到事半功倍的效果。这个算是学习kubernetes的一个知识点吧，也是学习前的入门。