blob: 5107e3b8598ba4065161285a19d881f5ccd8e1c3 [file] [log] [blame]
// Copyright 2015 Canonical Ltd.
// Licensed under the LGPLv3, see LICENCE file for details.
package utils
import (
"os"
"os/user"
"github.com/juju/errors"
)
// ResolveSudo returns the original username if sudo was used. The
// original username is extracted from the OS environment.
func ResolveSudo(username string) string {
return resolveSudo(username, os.Getenv)
}
func resolveSudo(username string, getenvFunc func(string) string) string {
if username != "root" {
return username
}
// sudo was probably called, get the original user.
if username := getenvFunc("SUDO_USER"); username != "" {
return username
}
return username
}
// EnvUsername returns the username from the OS environment.
func EnvUsername() (string, error) {
return os.Getenv("USER"), nil
}
// OSUsername returns the username of the current OS user (based on UID).
func OSUsername() (string, error) {
u, err := user.Current()
if err != nil {
return "", errors.Trace(err)
}
return u.Username, nil
}
// ResolveUsername returns the username determined by the provided
// functions. The functions are tried in the same order in which they
// were passed in. An error returned from any of them is immediately
// returned. If an empty string is returned then that signals that the
// function did not find the username and the next function is tried.
// Once a username is found, the provided resolveSudo func (if any) is
// called with that username and the result is returned. If no username
// is found then errors.NotFound is returned.
func ResolveUsername(resolveSudo func(string) string, usernameFuncs ...func() (string, error)) (string, error) {
for _, usernameFunc := range usernameFuncs {
username, err := usernameFunc()
if err != nil {
return "", errors.Trace(err)
}
if username != "" {
if resolveSudo != nil {
if original := resolveSudo(username); original != "" {
username = original
}
}
return username, nil
}
}
return "", errors.NotFoundf("username")
}
// LocalUsername determines the current username on the local host.
func LocalUsername() (string, error) {
username, err := ResolveUsername(ResolveSudo, EnvUsername, OSUsername)
if err != nil {
return "", errors.Annotatef(err, "cannot get current user from the environment: %v", os.Environ())
}
return username, nil
}