Setting absolute path does not work in Go for kubeconfig

I am making a call to kubectl from with a Go module like so:

getNsCmd := cmd.NewCmd("kubectl", "--kubeconfig", "~/.kube/<kube-config-file>", "get", "ns")

It works if I set the path like this:

getNsCmd := cmd.NewCmd("kubectl", "--kubeconfig", "../../../../.kube/<kube-config-file>", "get", "ns")

I am using the Go cmd package

Currently this module lives in another repo and that's why it has to navigate up four levels. I figure this is because the command is running from the perspective of this file, but it doesn't seem like it should have to. If it's simple running it as a cli command the first one (I would think) should work.

When I run this command from the cli manually it works just fine:

$ kubectl --kubeconfig ~/.kube/<kube-config-file> get ns

Using ~ as a shortcut is something specific to bash. ~ just grabs the user's $HOME directory, but does not work across all implementations of the shell. This is something that can be used from the terminal but not always from code (it's not shell-independent). However, go can also find the current user's home directory using os.UserHomeDir().

https://pkg.go.dev/os#UserHomeDir

Something like this should work

package main

import (
	"fmt"
	"os"
)

func main() {

	homeDir, _ := os.UserHomeDir()

	fmt.Printf("%s/.kube/<kube-config-file>", homeDir)
}

Output: /root/.kube/<kube-config-file>

Since the package you're using mentions that it wraps the Go's os/exec package, here is an excerpt from their documentation:

> Unlike the "system" library call from C and other languages, the
> os/exec package intentionally does not invoke the system shell and
> does not expand any glob patterns or handle other expansions,
> pipelines, or redirections typically done by shells. The package
> behaves more like C's "exec" family of functions. To expand glob
> patterns, either call the shell directly, taking care to escape any
> dangerous input, or use the path/filepath package's Glob function. To
> expand environment variables, use package os's ExpandEnv.

So I think you would want to try something like this:

import "os"

getNsCmd := cmd.NewCmd("kubectl", "--kubeconfig", os.ExpandEnv("$HOME/.kube/<kube-config-file>"), "get", "ns")

As others have mentioned I needed to grab the home directory environment var.
However I implemented it like this:

	homePath, _ := os.LookupEnv("HOME")

//

getNsCmd := cmd.NewCmd("kubectl", "--kubeconfig", homePath+"/.kube/<kube-config-file>", "get", "ns")