Improvements to fleetctl preview (#495)

- Download configuration on every run. This ensures that users always
  get the latest version.
- Pull latest Docker containers on every run.
- Add stop and reset commands (for cleanup).

Fixes #378

cmd/fleetctl/preview.go

@@ -27,11 +27,14 @@ const (
 func previewCommand() *cli.Command {
 	return &cli.Command{
 		Name:  "preview",
-		Usage: "Set up a preview deployment of the Fleet server",
-		UsageText: `Set up a preview deployment of the Fleet server using Docker and docker-compose. Docker tools must be available in the environment.
+		Usage: "Start a preview deployment of the Fleet server",
+		Description: `Start a preview deployment of the Fleet server using Docker and docker-compose. Docker tools must be available in the environment.
 
-This command will create a directory fleet-preview in the current working directory. Configurations can be modified in that directory.`,
-		Subcommands: []*cli.Command{},
+Use the stop and reset subcommands to manage the server and dependencies once started.`,
+		Subcommands: []*cli.Command{
+			previewStopCommand(),
+			previewResetCommand(),
+		},
 		Flags: []cli.Flag{
 			configFlag(),
 			contextFlag(),
@@ -42,20 +45,19 @@ This command will create a directory fleet-preview in the current working direct
 				return err
 			}
 
-			// Download files if necessary
+			// Download files every time to ensure the user gets the most up to date versions
 			previewDir := previewDirectory()
-			if _, err := os.Stat(
-				filepath.Join(previewDir, "docker-compose.yml"),
-			); err != nil {
 			fmt.Printf("Downloading dependencies into %s...\n", previewDir)
 			if err := downloadFiles(); err != nil {
 				return errors.Wrap(err, "Error downloading dependencies")
 			}
-			}
 
 			if err := os.Chdir(previewDir); err != nil {
 				return err
 			}
+			if _, err := os.Stat("docker-compose.yml"); err != nil {
+				return errors.Wrap(err, "docker-compose file not found in preview directory")
+			}
 
 			// Make sure the logs directory is writable, otherwise the Fleet
 			// server errors on startup. This can be a problem when running on
@@ -64,8 +66,15 @@ This command will create a directory fleet-preview in the current working direct
 				return errors.Wrap(err, "make logs writable")
 			}
 
+			fmt.Println("Pulling Docker dependencies...")
+			out, err := exec.Command("docker-compose", "pull", "mysql01", "redis01", "fleet01").CombinedOutput()
+			if err != nil {
+				fmt.Println(string(out))
+				return errors.Errorf("Failed to run docker-compose")
+			}
+
 			fmt.Println("Starting Docker containers...")
-			out, err := exec.Command("docker-compose", "up", "-d", "--remove-orphans", "mysql01", "redis01", "fleet01").CombinedOutput()
+			out, err = exec.Command("docker-compose", "up", "-d", "--remove-orphans", "mysql01", "redis01", "fleet01").CombinedOutput()
 			if err != nil {
 				fmt.Println(string(out))
 				return errors.Errorf("Failed to run docker-compose")
@@ -90,7 +99,10 @@ This command will create a directory fleet-preview in the current working direct
 
 			token, err := fleet.Setup(username, username, password, "Fleet Preview")
 			if err != nil {
-				if e, ok := err.(service.SetupAlreadyErr); !(ok && e.SetupAlready()) {
+				switch errors.Cause(err).(type) {
+				case service.SetupAlreadyErr:
+					// Ignore this error
+				default:
 					return errors.Wrap(err, "Error setting up Fleet")
 				}
 			}
@@ -304,3 +316,73 @@ func checkDocker() error {
 
 	return nil
 }
+
+func previewStopCommand() *cli.Command {
+	return &cli.Command{
+		Name:  "stop",
+		Usage: "Stop the Fleet preview server and dependencies",
+		Flags: []cli.Flag{
+			configFlag(),
+			contextFlag(),
+			debugFlag(),
+		},
+		Action: func(c *cli.Context) error {
+			if err := checkDocker(); err != nil {
+				return err
+			}
+
+			previewDir := previewDirectory()
+			if err := os.Chdir(previewDir); err != nil {
+				return err
+			}
+			if _, err := os.Stat("docker-compose.yml"); err != nil {
+				return errors.Wrap(err, "docker-compose file not found in preview directory")
+			}
+
+			out, err := exec.Command("docker-compose", "stop").CombinedOutput()
+			if err != nil {
+				fmt.Println(string(out))
+				return errors.Errorf("Failed to run docker-compose stop")
+			}
+
+			fmt.Println("Fleet preview server and dependencies stopped. Start again with fleetctl preview.")
+
+			return nil
+		},
+	}
+}
+
+func previewResetCommand() *cli.Command {
+	return &cli.Command{
+		Name:  "reset",
+		Usage: "Reset the Fleet preview server and dependencies",
+		Flags: []cli.Flag{
+			configFlag(),
+			contextFlag(),
+			debugFlag(),
+		},
+		Action: func(c *cli.Context) error {
+			if err := checkDocker(); err != nil {
+				return err
+			}
+
+			previewDir := previewDirectory()
+			if err := os.Chdir(previewDir); err != nil {
+				return err
+			}
+			if _, err := os.Stat("docker-compose.yml"); err != nil {
+				return errors.Wrap(err, "docker-compose file not found in preview directory")
+			}
+
+			out, err := exec.Command("docker-compose", "rm", "-sf").CombinedOutput()
+			if err != nil {
+				fmt.Println(string(out))
+				return errors.Errorf("Failed to run docker-compose rm -sf")
+			}
+
+			fmt.Println("Fleet preview server and dependencies reset. Start again with fleetctl preview.")
+
+			return nil
+		},
+	}
+}