cmd/run: Start o.fd.Flatpak.SessionHelper only for old containers

... that were created to have a bind mount at /run/host/monitor. Newly
created containers no longer need org.freedesktop.Flatpak.SessionHelper
and hence the D-Bus service doesn't need to be started for them.

#267

src/cmd/run.go

@@ -209,7 +209,7 @@ func runCommand(container string,
 		}
 	}
 
-	if _, err := utils.CallFlatpakSessionHelper(); err != nil {
+	if err := callFlatpakSessionHelper(container); err != nil {
 		return err
 	}
 
@@ -367,6 +367,37 @@ func runHelp(cmd *cobra.Command, args []string) {
 	}
 }
 
+func callFlatpakSessionHelper(container string) error {
+	logrus.Debugf("Inspecting mounts of container %s", container)
+
+	info, err := podman.Inspect("container", container)
+	if err != nil {
+		return fmt.Errorf("failed to inspect entry point of container %s", container)
+	}
+
+	var needsFlatpakSessionHelper bool
+
+	mounts := info["Mounts"].([]interface{})
+	for _, mount := range mounts {
+		destination := mount.(map[string]interface{})["Destination"].(string)
+		if destination == "/run/host/monitor" {
+			logrus.Debug("Requires org.freedesktop.Flatpak.SessionHelper")
+			needsFlatpakSessionHelper = true
+			break
+		}
+	}
+
+	if !needsFlatpakSessionHelper {
+		return nil
+	}
+
+	if _, err := utils.CallFlatpakSessionHelper(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func getEntryPointAndPID(container string) (string, int, error) {
 	logrus.Debugf("Inspecting entry point of container %s", container)