use return error handling in SetupRootless

There is no good reason to use logrus and os.Exit() here, other parts of
this function already return the error so do the same. The main podman
process will exit then with the normal formatted error message.

And also a comment about the last return which doesn't seem right.

Signed-off-by: Paul Holzinger <[email protected]>

Author: Luap99

pkg/domain/infra/abi/system_linux.go

@@ -59,6 +59,8 @@ func (ic *ContainerEngine) SetupRootless(_ context.Context, noMoveProcess bool,
 				}
 			}
 		}
+
+		// return early as we are already re-exec or root here so no need to join the rootless userns.
 		return nil
 	}
 
@@ -81,8 +83,7 @@ func (ic *ContainerEngine) SetupRootless(_ context.Context, noMoveProcess bool,
 	// if there is no pid file, try to join existing containers, and create a pause process.
 	ctrs, err := ic.Libpod.GetRunningContainers()
 	if err != nil {
-		logrus.Error(err.Error())
-		os.Exit(1)
+		return err
 	}
 
 	paths := []string{}
@@ -99,11 +100,12 @@ func (ic *ContainerEngine) SetupRootless(_ context.Context, noMoveProcess bool,
 		}
 	}
 	if err != nil {
-		logrus.Error(fmt.Errorf("invalid internal status, try resetting the pause process with %q: %w", os.Args[0]+" system migrate", err))
-		os.Exit(1)
+		return fmt.Errorf("invalid internal status, try resetting the pause process with %q: %w", os.Args[0]+" system migrate", err)
 	}
 	if became {
 		os.Exit(ret)
 	}
+	// FIXME: should this be an error? If we never re-exec that seems like a big issue here as we
+	// then call into code paths that expect to be run as uid 0.
 	return nil
 }