support agent region (#713)

* support agent region

* add select list for available regions if the regions flag is not set on agent create

* update initAgent

Author: real-danm

cmd/lk/agent.go

@@ -83,11 +83,10 @@ var (
 		Required: false,
 	}
 
-	regionFlag = &cli.StringSliceFlag{
-		Name:     "regions",
-		Usage:    "Region(s) to deploy the agent to. If unset, will deploy to the nearest region.",
+	regionFlag = &cli.StringFlag{
+		Name:     "region",
+		Usage:    "Region to deploy the agent to. If unset, will deploy to the nearest region.",
 		Required: false,
-		Hidden:   true,
 	}
 
 	skipSDKCheckFlag = &cli.BoolFlag{
@@ -141,7 +140,9 @@ var (
 							},
 						}},
 					}},
-					Flags:                     []cli.Flag{},
+					Flags: []cli.Flag{
+						regionFlag,
+					},
 					ArgsUsage:                 "[AGENT-NAME]",
 					DisableSliceFlagSeparator: true,
 				},
@@ -554,7 +555,31 @@ func createAgent(ctx context.Context, cmd *cli.Command) error {
 		}
 	}
 
-	regions := cmd.StringSlice("regions")
+	region := cmd.String("region")
+	if region == "" {
+		availableRegionsStr, ok := settingsMap["available_regions"]
+		if ok && availableRegionsStr != "" {
+			regionOptions := strings.Split(availableRegionsStr, ",")
+			for i, r := range regionOptions {
+				regionOptions[i] = strings.TrimSpace(r)
+			}
+
+			if err := huh.NewSelect[string]().
+				Title("Select region for agent deployment").
+				Options(huh.NewOptions(regionOptions...)...).
+				Value(&region).
+				WithTheme(util.Theme).
+				Run(); err != nil {
+				return err
+			}
+		} else {
+			// we shouldn't ever get here, but if we do, just default to us-east
+			logger.Debugw("no available regions found, defaulting to us-east. please contact LiveKit support if this is unexpected.")
+			region = "us-east"
+		}
+	}
+
+	regions := []string{region}
 	excludeFiles := []string{fmt.Sprintf("**/%s", config.LiveKitTOMLFile)}
 	resp, err := agentsClient.CreateAgent(ctx, os.DirFS(workingDir), secrets, regions, excludeFiles)
 	if err != nil {