kubebuilder alpha generate calls kubebuilder cmd from path instead of it's own

[bavarianbidi]

What broke? What's expected?

When running kubebuilder alpha generate, the generate-subcommand is directly invoking the kubebuilder binary in the current working directory.

This might lead to a failed execution in two different ways:

• your kubebuilder binary is not in PATH and you want to run the binary from somewhere else

$ /tmp/kubebuilder alpha generate
Error: kubebuilder not found in the path: exec: "kubebuilder": executable file not found in $PATH
Usage:
  kubebuilder alpha generate [flags]

Flags:
  -h, --help                help for generate
      --input-dir string    Specifies the full path to a Kubebuilder project file. If not provided, the current working directory is used.
      --output-dir string   Specifies the full path where the scaffolded files will be output. Defaults to a directory within the current working directory.

Global Flags:
      --plugins strings   plugin keys to be used for this subcommand execution

FATA error executing command: kubebuilder not found in the path: exec: "kubebuilder": executable file not found in $PATH 

• the version of kubebuilder in PATH is an older one where kubebuilder alpha generate is getting called (where e.g. not all plugins already exist - e.g. the newly introduced helm plugin)

Within alpha generate there is a check to verify if kubebuilder is in PATH:
exec.LookPath func from

kubebuilder/pkg/cli/alpha/internal/generate.go

Line 146 in 1f774a5

_, err = exec.LookPath("kubebuilder")

and than kubebuilder is getting called via RunCmd("kubebuilder:
https://github.com/search?q=repo%3Akubernetes-sigs%2Fkubebuilder+util.RunCmd%28%22kubebuilder+path%3Apkg%2Fcli%2Falpha%2Finternal%2F*&type=code

additional notes:
at least for Linux it could get solved by using the value of the _ environment variable (e.g.: os.Getenv("_") )

Reproducing this issue

1. ensure kubebuilder is not in your PATH
2. move kubebuilder binary to e.g. /tmp
3. change your working dir to an existing kubebuilder generated directory
4. run /tmp/kubebuilder alpha generate

KubeBuilder (CLI) Version

4.6.0

PROJECT version

3

Plugin versions

Other versions

No response

Extra Labels

No response

[camilamacedo86]

Hi @bavarianbidi 👋

Thank you for raise this one 👍 I agree that we need improve and fix it.
Do you have any suggestions on how we could handle this better?
How do you think we could solve this issue in a more robust or flexible way?

Also, I wanted to bring up a related point:

• If you look at the non-alpha commands in Kubebuilder, they generally work as CLI wrappers for the library functionality. Since Kubebuilder is ultimately a Go library, we get the CLI commands "for free" from the code structure. So — maybe we could make the alpha generate command behave more like kubebuilder create api|webhook, etc., rather than relying on a hardcoded call to the kubebuilder binary in the system PATH.

In the plugins we use: https://github.com/kubernetes-sigs/kubebuilder/blob/master/pkg/cli/cli.go#L50
AND for example: https://github.com/kubernetes-sigs/kubebuilder/blob/master/pkg/plugins/golang/v4/init.go#L48

[bavarianbidi]

Beside using the _ variable (where I do not now the usage outside Linux), go itself has
in the os package the os.Executable func.
https://pkg.go.dev/os#Executable

But the implementation is only for Linux and Android. And we release kubebuilder for darwin as well.

func executable() (string, error) {
	var procfn string
	switch runtime.GOOS {
	default:
		return "", errors.New("Executable not implemented for " + runtime.GOOS)
	case "linux", "android":
		procfn = "/proc/self/exe"
	}
	path, err := Readlink(procfn)

	// When the executable has been deleted then Readlink returns a
	// path appended with " (deleted)".
	return stringslite.TrimSuffix(path, " (deleted)"), err
}

[bavarianbidi]

Instead of spawning a new shell and calling the binary, I would prefer directly calling the corresponding function instead.

[camilamacedo86]

We have tests to cover this area. If you want to try pushing suggestions and then we check if they pass the tests first, it might be a good approach to start with. Please feel free to push a PR, and then we can review it.