docs: added documentations and help message for setup completions when used as kubectl plugin

cmd/completion.go

@@ -36,45 +36,80 @@ func (cc *CompletionCommand) Init() {
 }
 
 func longDetail() string {
-	return `To load completions:
+	return `To load completions for kubecm cli:
 
-Bash:
-  ` + "```" + `
-  $ source <(kubecm completion bash)
+For Bash users:
+
+  # To load completions for the current session, execute once:
+  source <(kubecm completion bash)
+
+  # To load completions for each session, execute once (you will need to start a new
+  # shell for this setup to take effect.):
 
-  # To load completions for each session, execute once:
   # Linux:
-  $ kubecm completion bash > /etc/bash_completion.d/kubecm
+  kubecm completion bash > /etc/bash_completion.d/kubecm
+
   # macOS:
-  $ kubecm completion bash > /usr/local/etc/bash_completion.d/kubecm
-  ` + "```" + `
-Zsh:
-  ` + "```" + `
+  kubecm completion bash > /usr/local/etc/bash_completion.d/kubecm
+
+For Zsh users, execute:
+
   # If shell completion is not already enabled in your environment,
   # you will need to enable it.  You can execute the following once:
 
-  $ echo "autoload -U compinit; compinit" >> ~/.zshrc
+  echo "autoload -U compinit; compinit" >> ~/.zshrc
+
+  # To load completions for each session, execute once (you will need to start a new
+  # shell for this setup to take effect.):
+  kubecm completion zsh > "${fpath[1]}/_kubecm"
 
-  # To load completions for each session, execute once:
-  $ kubecm completion zsh > "${fpath[1]}/_kubecm"
+For fish users, execute:
 
-  # You will need to start a new shell for this setup to take effect.
-  ` + "```" + `
-fish:
-  ` + "```" + `
-  $ kubecm completion fish | source
+  # Load completions for the current session, execute once:
+  kubecm completion fish | source
 
-  # To load completions for each session, execute once:
-  $ kubecm completion fish > ~/.config/fish/completions/kubecm.fish
-  ` + "```" + `
-PowerShell:
-  ` + "```" + `
-  PS> kubecm completion powershell | Out-String | Invoke-Expression
+  # Load completions for each session, execute once (you will need to start a new
+  # shell for this setup to take effect.):
+  kubecm completion fish > ~/.config/fish/completions/kubecm.fish
+
+For PowerShell users, execute:
+
+  # To load completions for the current session, execute once:
+  kubecm completion powershell | Out-String | Invoke-Expression
 
   # To load completions for every new session, run:
-  PS> kubecm completion powershell > kubecm.ps1
+  kubecm completion powershell > kubecm.ps1
   # and source this file from your PowerShell profile.
-  ` + "```" + `
+
+---
+
+To load completions for kubectl kc when used as kubectl plugin:
+
+1. Use the following command as one-liner to add the completion to the current shell session:
+
+  mkdir -p ~/.config/.kubectl-plugin-completions
+  cat <<EOF >~/.config/.kubectl-plugin-completions/kubectl_complete-kc
+  #!/usr/bin/env sh
+
+  # Call the __complete command passing it all arguments
+  kubectl kc __complete "\$@"
+  EOF
+  chmod +x ~/.config/.kubectl-plugin-completions/kubectl_complete-kc
+
+2. Append the directory to the $PATH environment variable.
+
+For Bash users, execute:
+
+  echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.bashrc
+
+For Zsh users, execute:
+
+  echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.zshrc
+
+For fish users, execute:
+
+  fish_add_path ~/.config/.kubectl-plugin-completions
+
 ---
 `
 }

docs/en-us/cli/kubecm_completion.md

@@ -1,52 +1,171 @@
-## kubecm completion
+## `kubecm` completion
 
 Generate completion script
 
 ### Synopsis
 
-To load completions:
+Please follow the guide below to configure auto-completion for both regular `kubecm` and `kubectl kc` (as `kubectl` plugin).
+
+#### Configuration for auto-completion of `kubecm`
 
 Bash:
-  ```
-  $ source <(kubecm completion bash)
-
-  # To load completions for each session, execute once:
-  # Linux:
-  $ kubecm completion bash > /etc/bash_completion.d/kubecm
-  # macOS:
-  $ kubecm completion bash > /usr/local/etc/bash_completion.d/kubecm
-  ```
+
+```shell
+# To load completions for the current session, execute once:
+$ source <(kubecm completion bash)
+
+# To load completions for each session, execute once:
+# Linux:
+$ kubecm completion bash > /etc/bash_completion.d/kubecm
+
+# macOS:
+$ kubecm completion bash > /usr/local/etc/bash_completion.d/kubecm
+
+# You will need to start a new shell for this setup to take effect.
+```
+
 Zsh:
-  ```
-  # If shell completion is not already enabled in your environment,
-  # you will need to enable it.  You can execute the following once:
 
-  $ echo "autoload -U compinit; compinit" >> ~/.zshrc
+```shell
+# If shell completion is not already enabled in your environment,
+# you will need to enable it.  You can execute the following once:
+
+$ echo "autoload -U compinit; compinit" >> ~/.zshrc
+
+# To load completions for each session, execute once:
+$ kubecm completion zsh > "${fpath[1]}/_kubecm"
 
-  # To load completions for each session, execute once:
-  $ kubecm completion zsh > "${fpath[1]}/_kubecm"
+# You will need to start a new shell for this setup to take effect.
+```
 
-  # You will need to start a new shell for this setup to take effect.
-  ```
 fish:
-  ```
-  $ kubecm completion fish | source
 
-  # To load completions for each session, execute once:
-  $ kubecm completion fish > ~/.config/fish/completions/kubecm.fish
-  ```
+```shell
+# To load completions for the current session, execute once:
+$ kubecm completion fish | source
+
+# To load completions for each session, execute once:
+$ kubecm completion fish > ~/.config/fish/completions/kubecm.fish
+
+# You will need to start a new shell for this setup to take effect.
+```
+
 PowerShell:
-  ```
-  PS> kubecm completion powershell | Out-String | Invoke-Expression
 
-  # To load completions for every new session, run:
-  PS> kubecm completion powershell > kubecm.ps1
-  # and source this file from your PowerShell profile.
-  ```
----
+```powershell
+# To load completions for the current session, execute once:
+PS> kubecm completion powershell | Out-String | Invoke-Expression
+
+# To load completions for every new session, run:
+PS> kubecm completion powershell > kubecm.ps1
+# and source this file from your PowerShell profile.
+```
+
+#### Configuration for auto-completion of `kubectl kc` (as `kubectl` plugin)
+
+Unlike direct execution of `kubecm`, when executed as a `kubectl` plugin (i.e., using `kubecm` installed with [`krew`](https://krew.sigs.k8s.io/) or invoked as `kubectl kc`), auto-completion requires some additional configuration based on [Configuration for auto-completion of `kubecm`](#configuration-for-auto-completion-of-kubecm) to enable auto-completion when use `kubectl kc` + <kbd>TAB</kbd>.
+
+> How does this work?
+>
+> In a nut shell, `kubectl` looks for a executable script or binary that named with the `kubectl_complete-<plugin-name>` pattern as a **convention** in the `$PATH` environment variable. If it does find, `kubectl` will pass the arguments that calls from `kubectl <plugin-name>` to the conventionally configured auto-completion script to seek out for completion candidates list.
+
+Therefore, in order for the auto-completion of `kubectl kc` + <kbd>TAB</kbd> to work, there are several options for you to choose from and configure.
+
+Note: **PowerShell's auto-completion requires no additional configuration and works right out of the box.**
+
+##### Use pre-written auto-completion script
+
+You can download the pre-written auto-completion script and configure it automatically by executing the following command:
+
+```shell
+mkdir -p ~/.config/.kubectl-plugin-completions && \
+  curl -LO "https://raw.githubusercontent.com/sunny0826/kubecm/master/hack/kubectl-plugin-completions/kubectl_complete-kc.sh" && \
+  mv kubectl_complete-kc.sh ~/.config/.kubectl-plugin-completions/kubectl_complete-kc && \
+  chmod +x ~/.config/.kubectl-plugin-completions/kubectl_complete-kc
+```
+
+Append the `~/.config/.kubectl-plugin-completions` directory we've created just now to the `$PATH` environment variable to satisfy the auto-completion convention of the `kubectl` plugin:
+
+Bash:
+
+```shell
+echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.bashrc
+```
+
+Zsh:
+
+```shell
+echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.zshrc
+```
 
+Fish:
 
+```shell
+fish_add_path ~/.config/.kubectl-plugin-completions
 ```
+
+##### Manually configure auto-completion script
+
+1. Create the directory `.config/.kubectl-plugin-completions` for the auto-completion scripts:
+
+```shell
+mkdir -p ~/.config/.kubectl-plugin-completions
+```
+
+2. Write the following content into an executable shell script named `kubectl_complete-kc` in this directory:
+
+```shell
+#!/usr/bin/env sh
+
+# Call the __complete command passing it all arguments
+kubectl kc __complete "$@"
+```
+
+You can also complete this step as one-liner using the following command:
+
+```shell
+cat <<EOF >~/.config/.kubectl-plugin-completions/kubectl_complete-kc
+#!/usr/bin/env sh
+
+# Call the __complete command passing it all arguments
+kubectl kc __complete "\$@"
+EOF
+```
+
+3. Add executable permissions to the file:
+
+```shell
+chmod +x ~/.config/.kubectl-plugin-completions/kubectl_complete-kc
+```
+
+Append the `~/.config/.kubectl-plugin-completion` directory we've created just now to the `$PATH` environment variable to satisfy the auto-completion convention of the `kubectl` plugin:
+
+Bash:
+
+```shell
+echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.bashrc
+```
+
+Zsh:
+
+```shell
+echo 'export PATH=$PATH:~/.config/.kubectl-plugin-completions' >> ~/.zshrc
+```
+
+Fish:
+
+```shell
+fish_add_path ~/.config/.kubectl-plugin-completions
+```
+
+##### Use a `kubectl` plugin `kubectl-plugin_completion` to automatically generate and configure
+
+Please refer to the [`kubectl-plugin_completion`](https://github.com/marckhouzam/kubectl-plugin_completion) plugin's documentation for configuration.
+
+---
+
+
+```shell
 kubecm completion [bash|zsh|fish|powershell] [flags]
 ```
 
@@ -67,4 +186,3 @@ kubecm completion [bash|zsh|fish|powershell] [flags]
 ### SEE ALSO
 
 * [kubecm](kubecm.md)	 - KubeConfig Manager.
-