util: Add CheckIfRoot

Replace IsUserRoot with CheckIfRoot. This allows all functions to use
the same error handling when a user is not root.

3 files changed, 10 insertions, 5 deletions

diff --git a/util/errors.go b/util/errors.go
index fada687..f0b9403 100644
--- a/util/errors.go
+++ b/util/errors.go
@@ -29,6 +29,8 @@ import (
 )
 
 var (
+	// ErrNotRoot indicates the action is restricted to the superuser.
+	ErrNotRoot = errors.New("only root can perform this action")
 	// ErrSkipIntegration indicates integration tests shouldn't be run.
 	ErrSkipIntegration = errors.New("skipping integration test")
 )
diff --git a/util/users.go b/util/users.go
index 92affa8..49abd32 100644
--- a/util/users.go
+++ b/util/users.go
@@ -48,3 +48,11 @@ func GetUser(uid int) *user.User {
 func CurrentUser() *user.User {
 	return GetUser(CurrentUserID())
 }
+
+// CheckIfRoot returns ErrNotRoot if the current user is not the root user.
+func CheckIfRoot() error {
+	if id := CurrentUserID(); id != 0 {
+		return ErrNotRoot
+	}
+	return nil
+}
diff --git a/util/util.go b/util/util.go
index ed78519..df24a99 100644
--- a/util/util.go
+++ b/util/util.go
@@ -117,8 +117,3 @@ func AtoiOrPanic(input string) int {
 	}
 	return i
 }
-
-// IsUserRoot checks if the effective user is root.
-func IsUserRoot() bool {
-	return CurrentUserID() == 0
-}