fnctl: add heroku-like app config interface (#277)

fnctl/apps.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"os"
@@ -35,9 +36,33 @@ func apps() cli.Command {
 				},
 			},
 			{
-				Name:   "describe",
-				Usage:  "describe an existing app",
-				Action: a.describe,
+				Name:   "config",
+				Usage:  "operate an application configuration set",
+				Action: a.configList,
+				Flags: []cli.Flag{
+					cli.BoolFlag{
+						Name:  "shell",
+						Usage: "output in shell format",
+					},
+					cli.BoolFlag{
+						Name:  "json",
+						Usage: "output in JSON format",
+					},
+				},
+				Subcommands: []cli.Command{
+					{
+						Name:        "set",
+						Description: "store a configuration key for this application",
+						Usage:       "<app> <key> <value>",
+						Action:      a.configSet,
+					},
+					{
+						Name:        "unset",
+						Description: "remove a configuration key for this application",
+						Usage:       "<app> <key> <value>",
+						Action:      a.configUnset,
+					},
+				},
 			},
 		},
 	}
@@ -87,7 +112,7 @@ func (a *appsCmd) create(c *cli.Context) error {
 	return nil
 }
 
-func (a *appsCmd) describe(c *cli.Context) error {
+func (a *appsCmd) configList(c *cli.Context) error {
 	if c.Args().First() == "" {
 		return errors.New("error: app description takes one argument, an app name")
 	}
@@ -102,15 +127,110 @@ func (a *appsCmd) describe(c *cli.Context) error {
 		return fmt.Errorf("error creating app: %v", err)
 	}
 
-	fmt.Println("app:", wrapper.App.Name)
-	if config := wrapper.App.Config; len(config) > 0 {
-		fmt.Println("configuration:")
-		w := tabwriter.NewWriter(os.Stdout, 0, 8, 1, ' ', 0)
-		fmt.Fprintln(w, "key\tvalue")
+	config := wrapper.App.Config
+	if len(config) == 0 {
+		return errors.New("this application has no configurations")
+	}
+
+	if c.Bool("json") {
+		if err := json.NewEncoder(os.Stdout).Encode(config); err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+	} else if c.Bool("shell") {
 		for k, v := range wrapper.App.Config {
-			fmt.Fprint(w, k, "\t", v, "\n")
+			fmt.Print("export ", k, "=", v, "\n")
+		}
+	} else {
+		fmt.Println(wrapper.App.Name, "configuration:")
+		w := tabwriter.NewWriter(os.Stdout, 0, 8, 1, ' ', 0)
+		for k, v := range config {
+			fmt.Fprint(w, k, ":\t", v, "\n")
 		}
 		w.Flush()
 	}
 	return nil
 }
+
+func (a *appsCmd) configSet(c *cli.Context) error {
+	if c.Args().Get(0) == "" || c.Args().Get(1) == "" || c.Args().Get(2) == "" {
+		return errors.New("error: application configuration setting takes three arguments: an app name, a key and a value")
+	}
+
+	if err := resetBasePath(&a.Configuration); err != nil {
+		return fmt.Errorf("error setting endpoint: %v", err)
+	}
+
+	appName := c.Args().Get(0)
+	key := c.Args().Get(1)
+	value := c.Args().Get(2)
+
+	wrapper, _, err := a.AppsAppGet(appName)
+	if err != nil {
+		return fmt.Errorf("error creating app: %v", err)
+	}
+
+	config := wrapper.App.Config
+
+	if config == nil {
+		config = make(map[string]string)
+	}
+
+	config[key] = value
+
+	if err := a.storeApp(appName, config); err != nil {
+		return fmt.Errorf("error updating app configuration: %v", err)
+	}
+
+	fmt.Println(wrapper.App.Name, "updated", key, "with", value)
+	return nil
+}
+
+func (a *appsCmd) configUnset(c *cli.Context) error {
+	if c.Args().Get(0) == "" || c.Args().Get(1) == "" {
+		return errors.New("error: application configuration setting takes three arguments: an app name, a key and a value")
+	}
+
+	if err := resetBasePath(&a.Configuration); err != nil {
+		return fmt.Errorf("error setting endpoint: %v", err)
+	}
+
+	appName := c.Args().Get(0)
+	key := c.Args().Get(1)
+
+	wrapper, _, err := a.AppsAppGet(appName)
+	if err != nil {
+		return fmt.Errorf("error creating app: %v", err)
+	}
+
+	config := wrapper.App.Config
+
+	if config == nil {
+		config = make(map[string]string)
+	}
+
+	if _, ok := config[key]; !ok {
+		return fmt.Errorf("configuration key %s not found", key)
+	}
+
+	delete(config, key)
+
+	if err := a.storeApp(appName, config); err != nil {
+		return fmt.Errorf("error updating app configuration: %v", err)
+	}
+
+	fmt.Println(wrapper.App.Name, "removed", key)
+	return nil
+}
+
+func (a *appsCmd) storeApp(appName string, config map[string]string) error {
+	body := functions.AppWrapper{App: functions.App{
+		Name:   appName,
+		Config: config,
+	}}
+
+	if _, _, err := a.AppsPost(body); err != nil {
+		return fmt.Errorf("error updating app configuration: %v", err)
+	}
+	return nil
+}