backend: add --json flag to always output JSON

cmd/backend/backend.go

@@ -18,12 +18,14 @@ import (
 
 var (
 	options []string
+	useJSON bool
 )
 
 func init() {
 	cmd.Root.AddCommand(commandDefinition)
 	cmdFlags := commandDefinition.Flags()
 	flags.StringArrayVarP(cmdFlags, &options, "option", "o", options, "Option in the form name=value or name.")
+	flags.BoolVarP(cmdFlags, &useJSON, "json", "", useJSON, "Always output in JSON format.")
 }
 
 var commandDefinition = &cobra.Command{
@@ -97,6 +99,10 @@ Note to run these commands on a running backend then see
 
 			}
 			// Output the result
+			writeJSON := false
+			if useJSON {
+				writeJSON = true
+			} else {
 				switch x := out.(type) {
 				case nil:
 				case string:
@@ -106,6 +112,10 @@ Note to run these commands on a running backend then see
 						fmt.Println(line)
 					}
 				default:
+					writeJSON = true
+				}
+			}
+			if writeJSON {
 				// Write indented JSON to the output
 				enc := json.NewEncoder(os.Stdout)
 				enc.SetIndent("", "\t")