mirror of
https://github.com/tailscale/tailscale.git
synced 2024-11-30 05:25:35 +00:00
55 lines
1.4 KiB
Go
55 lines
1.4 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
|
|
// SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
package osuser
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"os/exec"
|
|
"os/user"
|
|
"runtime"
|
|
"strings"
|
|
"time"
|
|
|
|
"tailscale.com/version/distro"
|
|
)
|
|
|
|
// GetGroupIds returns the list of group IDs that the user is a member of, or
|
|
// an error. It will first try to use the 'id' command to get the group IDs,
|
|
// and if that fails, it will fall back to the user.GroupIds method.
|
|
func GetGroupIds(user *user.User) ([]string, error) {
|
|
if runtime.GOOS != "linux" {
|
|
return user.GroupIds()
|
|
}
|
|
|
|
if distro.Get() == distro.Gokrazy {
|
|
// Gokrazy is a single-user appliance with ~no userspace.
|
|
// There aren't users to look up (no /etc/passwd, etc)
|
|
// so rather than fail below, just hardcode root.
|
|
// TODO(bradfitz): fix os/user upstream instead?
|
|
return []string{"0"}, nil
|
|
}
|
|
|
|
if ids, err := getGroupIdsWithId(user.Username); err == nil {
|
|
return ids, nil
|
|
}
|
|
return user.GroupIds()
|
|
}
|
|
|
|
func getGroupIdsWithId(usernameOrUID string) ([]string, error) {
|
|
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
|
|
defer cancel()
|
|
|
|
cmd := exec.CommandContext(ctx, "id", "-Gz", usernameOrUID)
|
|
out, err := cmd.Output()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("running 'id' command: %w", err)
|
|
}
|
|
return parseGroupIds(out), nil
|
|
}
|
|
|
|
func parseGroupIds(cmdOutput []byte) []string {
|
|
return strings.Split(strings.Trim(string(cmdOutput), "\n\x00"), "\x00")
|
|
}
|