cobra: move engine shutdown to Execute

If the run errors, cobra does not execute post runs.  It is a somehow
known issue (spf13/cobra#914) but problematic
for Podmand as the runtime is shutdown during post run.

Since some commands overwrite the post run and a general lack in cobra
of post runs on errors, move the shutting down the engines directly into
Execute.  Fixing the issue may fix a number of flakes.

Note that the shutdowns are NOPs for the remote client.

Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

cmd/podman/root.go

@@ -115,6 +115,22 @@ func Execute() {
 		}
 		fmt.Fprintln(os.Stderr, formatError(err))
 	}
+
+	if requireCleanup {
+		// The cobra post-run is not being executed in case of
+		// a previous error , so make sure that the engine(s)
+		// are correctly shutdown.
+		//
+		// See https://github.com/spf13/cobra/issues/914
+		logrus.Debugf("Shutting down engines")
+		if engine := registry.ImageEngine(); engine != nil {
+			engine.Shutdown(registry.Context())
+		}
+		if engine := registry.ContainerEngine(); engine != nil {
+			engine.Shutdown(registry.Context())
+		}
+	}
+
 	os.Exit(registry.GetExitCode())
 }
 
@@ -298,13 +314,6 @@ func persistentPreRunE(cmd *cobra.Command, args []string) error {
 func persistentPostRunE(cmd *cobra.Command, args []string) error {
 	logrus.Debugf("Called %s.PersistentPostRunE(%s)", cmd.Name(), strings.Join(os.Args, " "))
 
-	if !requireCleanup {
-		return nil
-	}
-
-	registry.ImageEngine().Shutdown(registry.Context())
-	registry.ContainerEngine().Shutdown(registry.Context())
-
 	if registry.IsRemote() {
 		return nil
 	}

test/system/001-basic.bats

@@ -238,4 +238,11 @@ run_podman --noout system connection ls
     is "$output" "" "output should be empty"
 }
 
+@test "podman - shutdown engines" {
+    run_podman --log-level=debug run --rm $IMAGE true
+    is "$output" ".*Shutting down engines.*"
+    run_podman 125 --log-level=debug run dockah://rien.de/rien:latest
+    is "${lines[-1]}" ".*Shutting down engines"
+}
+
 # vim: filetype=sh