f74b7a6e39
This removes indirect dependencies from go.mod, and includes the fix for the missing -help flag info. The latest cobra release is v1.2.1. Given that there were minor security-related dependency cleanup during v1.2 release, I was tempted to pick up the latest version, but that caused dependency updates in golang.org/x/sys and golang.org/x/tools which may be too recent (golang.org/x/* follow the go's release support policy, so recent versions may not be compatible with go versions beyond go's official version support policy). Verified that dlv still builds with go1.12.x. (go1.12 is the oldest version of go that can build the latest delve already). $ go get -d github.com/spf13/cobra@v1.1.3 $ go mod tidy $ go mod vendor $ go run _scripts/gen-usage-docs.go
92 lines
3.5 KiB
Markdown
92 lines
3.5 KiB
Markdown
# 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.
|
|
|
|
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
|
|
}
|
|
```
|