Workaround for Cobra.Command handling of PersistentPreRunE not setting log level (#372)

Signed-off-by: David Chung <[email protected]>

Author: David Chung

cmd/cli/flavor.go

@@ -28,6 +28,14 @@ func flavorPluginCommand(plugins func() discovery.Plugins) *cobra.Command {
 	name := cmd.PersistentFlags().String("name", "", "Name of plugin")
 
 	cmd.PersistentPreRunE = func(c *cobra.Command, args []string) error {
+		if err := upTree(c, func(x *cobra.Command, argv []string) error {
+			if x.PersistentPreRunE != nil {
+				return x.PersistentPreRunE(x, argv)
+			}
+			return nil
+		}); err != nil {
+			return err
+		}
 
 		endpoint, err := plugins().Find(plugin.Name(*name))
 		if err != nil {

cmd/cli/group.go

@@ -31,6 +31,14 @@ func groupPluginCommand(plugins func() discovery.Plugins) *cobra.Command {
 	}
 	name := cmd.PersistentFlags().String("name", DefaultGroupPluginName, "Name of plugin")
 	cmd.PersistentPreRunE = func(c *cobra.Command, args []string) error {
+		if err := upTree(c, func(x *cobra.Command, argv []string) error {
+			if x.PersistentPreRunE != nil {
+				return x.PersistentPreRunE(x, argv)
+			}
+			return nil
+		}); err != nil {
+			return err
+		}
 
 		endpoint, err := plugins().Find(plugin.Name(*name))
 		if err != nil {

cmd/cli/instance.go

@@ -26,6 +26,14 @@ func instancePluginCommand(plugins func() discovery.Plugins) *cobra.Command {
 	}
 	name := cmd.PersistentFlags().String("name", "", "Name of plugin")
 	cmd.PersistentPreRunE = func(c *cobra.Command, args []string) error {
+		if err := upTree(c, func(x *cobra.Command, argv []string) error {
+			if x.PersistentPreRunE != nil {
+				return x.PersistentPreRunE(x, argv)
+			}
+			return nil
+		}); err != nil {
+			return err
+		}
 
 		endpoint, err := plugins().Find(plugin.Name(*name))
 		if err != nil {

cmd/cli/main.go

@@ -19,8 +19,9 @@ func main() {
 		Short: "infrakit cli",
 	}
 	logLevel := cmd.PersistentFlags().Int("log", cli.DefaultLogLevel, "Logging level. 0 is least verbose. Max is 5")
-	cmd.PersistentPreRun = func(c *cobra.Command, args []string) {
+	cmd.PersistentPreRunE = func(c *cobra.Command, args []string) error {
 		cli.SetLogLevel(*logLevel)
+		return nil
 	}
 
 	// Don't print usage text for any error returned from a RunE function.  Only print it when explicitly requested.
@@ -57,3 +58,14 @@ func assertNotNil(message string, f interface{}) {
 		os.Exit(1)
 	}
 }
+
+// upTree traverses up the command tree and starts executing the do function in the order from top
+// of the command tree to the bottom.  Cobra commands executes only one level of PersistentPreRunE
+// in reverse order.  This breaks our model of setting log levels at the very top and have the log level
+// set throughout the entire hierarchy of command execution.
+func upTree(c *cobra.Command, do func(*cobra.Command, []string) error) error {
+	if p := c.Parent(); p != nil {
+		return upTree(p, do)
+	}
+	return do(c, c.Flags().Args())
+}

cmd/cli/manager.go

@@ -27,6 +27,14 @@ func managerCommand(plugins func() discovery.Plugins) *cobra.Command {
 		Short: "Access the manager",
 	}
 	cmd.PersistentPreRunE = func(c *cobra.Command, args []string) error {
+		if err := upTree(c, func(x *cobra.Command, argv []string) error {
+			if x.PersistentPreRunE != nil {
+				return x.PersistentPreRunE(x, argv)
+			}
+			return nil
+		}); err != nil {
+			return err
+		}
 
 		// Scan for a manager
 		pm, err := plugins().List()