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https://github.com/spf13/cobra.git
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2c5a0d300f
Replace the current Zsh completion with a Zsh completion solution based
on Go completions. This allows to support custom completions (based
on Go completions), but also to standardize the behavior of completion
across all shells.
Also, add support to Go completions for the bash completion annotations:
BashCompFilenameExt (including Command.MarkFlagFilename() family)
- still supported by zsh
BashCompSubdirsInDir - now supported by zsh
BashCompOneRequiredFlag (including Command.MarkFlagRequired() family)
- now supported by zsh and fish
Finally, remove the suggestin of the = form of flag completion.
The = form is supported, but it will not be suggested to avoid having
duplicated suggestions.
92 lines
3.5 KiB
Markdown
92 lines
3.5 KiB
Markdown
# Generating Bash Completions For Your cobra.Command
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Please refer to [Shell Completions](shell_completions.md) for details.
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## Bash legacy dynamic completions
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For backwards-compatibility, Cobra still supports its legacy dynamic completion solution (described below). Unlike the `ValidArgsFunction` solution, the legacy solution will only work for Bash shell-completion and not for other shells. This legacy solution can be used along-side `ValidArgsFunction` and `RegisterFlagCompletionFunc()`, as long as both solutions are not used for the same command. This provides a path to gradually migrate from the legacy solution to the new solution.
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The legacy solution allows you to inject bash functions into the bash completion script. Those bash functions are responsible for providing the completion choices for your own completions.
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Some code that works in kubernetes:
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```bash
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const (
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bash_completion_func = `__kubectl_parse_get()
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{
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local kubectl_output out
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if kubectl_output=$(kubectl get --no-headers "$1" 2>/dev/null); then
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out=($(echo "${kubectl_output}" | awk '{print $1}'))
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COMPREPLY=( $( compgen -W "${out[*]}" -- "$cur" ) )
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fi
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}
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__kubectl_get_resource()
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{
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if [[ ${#nouns[@]} -eq 0 ]]; then
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return 1
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fi
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__kubectl_parse_get ${nouns[${#nouns[@]} -1]}
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if [[ $? -eq 0 ]]; then
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return 0
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fi
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}
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__kubectl_custom_func() {
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case ${last_command} in
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kubectl_get | kubectl_describe | kubectl_delete | kubectl_stop)
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__kubectl_get_resource
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return
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;;
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*)
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;;
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esac
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}
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`)
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```
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And then I set that in my command definition:
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```go
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cmds := &cobra.Command{
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Use: "kubectl",
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Short: "kubectl controls the Kubernetes cluster manager",
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Long: `kubectl controls the Kubernetes cluster manager.
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Find more information at https://github.com/GoogleCloudPlatform/kubernetes.`,
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Run: runHelp,
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BashCompletionFunction: bash_completion_func,
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}
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```
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The `BashCompletionFunction` option is really only valid/useful on the root command. Doing the above will cause `__kubectl_custom_func()` (`__<command-use>_custom_func()`) to be called when the built in processor was unable to find a solution. In the case of kubernetes a valid command might look something like `kubectl get pod [mypod]`. If you type `kubectl get pod [tab][tab]` the `__kubectl_customc_func()` will run because the cobra.Command only understood "kubectl" and "get." `__kubectl_custom_func()` will see that the cobra.Command is "kubectl_get" and will thus call another helper `__kubectl_get_resource()`. `__kubectl_get_resource` will look at the 'nouns' collected. In our example the only noun will be `pod`. So it will call `__kubectl_parse_get pod`. `__kubectl_parse_get` will actually call out to kubernetes and get any pods. It will then set `COMPREPLY` to valid pods!
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Similarly, for flags:
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```go
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annotation := make(map[string][]string)
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annotation[cobra.BashCompCustom] = []string{"__kubectl_get_namespaces"}
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flag := &pflag.Flag{
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Name: "namespace",
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Usage: usage,
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Annotations: annotation,
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}
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cmd.Flags().AddFlag(flag)
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```
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In addition add the `__kubectl_get_namespaces` implementation in the `BashCompletionFunction`
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value, e.g.:
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```bash
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__kubectl_get_namespaces()
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{
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local template
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template="{{ range .items }}{{ .metadata.name }} {{ end }}"
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local kubectl_out
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if kubectl_out=$(kubectl get -o template --template="${template}" namespace 2>/dev/null); then
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COMPREPLY=( $( compgen -W "${kubectl_out}[*]" -- "$cur" ) )
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fi
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}
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```
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