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diff --git a/vendor/github.com/spf13/cobra/bash_completions.md b/vendor/github.com/spf13/cobra/bash_completions.md new file mode 100644 index 000000000..52919b2fa --- /dev/null +++ b/vendor/github.com/spf13/cobra/bash_completions.md @@ -0,0 +1,93 @@ +# Generating Bash Completions For Your cobra.Command + +Please refer to [Shell Completions](shell_completions.md) for details. + +## Bash legacy dynamic completions + +For backward 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. + +**Note**: Cobra's default `completion` command uses bash completion V2. If you are currently using Cobra's legacy dynamic completion solution, you should not use the default `completion` command but continue using your own. + +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. + +Some code that works in kubernetes: + +```bash +const ( + bash_completion_func = `__kubectl_parse_get() +{ + local kubectl_output out + if kubectl_output=$(kubectl get --no-headers "$1" 2>/dev/null); then + out=($(echo "${kubectl_output}" | awk '{print $1}')) + COMPREPLY=( $( compgen -W "${out[*]}" -- "$cur" ) ) + fi +} + +__kubectl_get_resource() +{ + if [[ ${#nouns[@]} -eq 0 ]]; then + return 1 + fi + __kubectl_parse_get ${nouns[${#nouns[@]} -1]} + if [[ $? -eq 0 ]]; then + return 0 + fi +} + +__kubectl_custom_func() { + case ${last_command} in + kubectl_get | kubectl_describe | kubectl_delete | kubectl_stop) + __kubectl_get_resource + return + ;; + *) + ;; + esac +} +`) +``` + +And then I set that in my command definition: + +```go +cmds := &cobra.Command{ + Use: "kubectl", + Short: "kubectl controls the Kubernetes cluster manager", + Long: `kubectl controls the Kubernetes cluster manager. + +Find more information at https://github.com/GoogleCloudPlatform/kubernetes.`, + Run: runHelp, + BashCompletionFunction: bash_completion_func, +} +``` + +The `BashCompletionFunction` option is really only valid/useful on the root command. Doing the above will cause `__kubectl_custom_func()` (`__<command-use>_custom_func()`) to be called when the built in processor was unable to find a solution. In the case of kubernetes a valid command might look something like `kubectl get pod [mypod]`. If you type `kubectl get pod [tab][tab]` the `__kubectl_customc_func()` will run because the cobra.Command only understood "kubectl" and "get." `__kubectl_custom_func()` will see that the cobra.Command is "kubectl_get" and will thus call another helper `__kubectl_get_resource()`. `__kubectl_get_resource` will look at the 'nouns' collected. In our example the only noun will be `pod`. So it will call `__kubectl_parse_get pod`. `__kubectl_parse_get` will actually call out to kubernetes and get any pods. It will then set `COMPREPLY` to valid pods! + +Similarly, for flags: + +```go + annotation := make(map[string][]string) + annotation[cobra.BashCompCustom] = []string{"__kubectl_get_namespaces"} + + flag := &pflag.Flag{ + Name: "namespace", + Usage: usage, + Annotations: annotation, + } + cmd.Flags().AddFlag(flag) +``` + +In addition add the `__kubectl_get_namespaces` implementation in the `BashCompletionFunction` +value, e.g.: + +```bash +__kubectl_get_namespaces() +{ + local template + template="{{ range .items }}{{ .metadata.name }} {{ end }}" + local kubectl_out + if kubectl_out=$(kubectl get -o template --template="${template}" namespace 2>/dev/null); then + COMPREPLY=( $( compgen -W "${kubectl_out}[*]" -- "$cur" ) ) + fi +} +``` |