ref(deisctl): replace if/else trees with switch

Author: mboersma

deisctl/backend/fleet/fleet_test.go

@@ -70,10 +70,11 @@ func (c *stubFleetClient) SetUnitTargetState(name, target string) error {
 	var activeState string
 	var subState string
 
-	if target == "loaded" {
+	switch target {
+	case "loaded":
 		activeState = "inactive"
 		subState = "dead"
-	} else if target == "launched" {
+	case "launched":
 		activeState = "active"
 		subState = "running"
 	}

deisctl/backend/fleet/scale.go

@@ -28,12 +28,12 @@ func (c *FleetClient) Scale(
 	}
 
 	timesToScale := int(math.Abs(float64(requested - len(components))))
-	if timesToScale == 0 {
+	switch {
+	case timesToScale == 0:
 		return
-	}
-	if requested-len(components) > 0 {
+	case requested-len(components) > 0:
 		c.scaleUp(component, len(components), timesToScale, wg, out, ew)
-	} else {
+	default:
 		c.scaleDown(component, len(components), timesToScale, wg, out, ew)
 	}
 }

deisctl/backend/fleet/ssh.go

@@ -134,15 +134,14 @@ func (sshCommandRunner) RemoteCommand(cmd string, addr string, timeout time.Dura
 // findUnits returns the machine ID of a running unit
 func (c *FleetClient) findUnit(name string) (machID string, err error) {
 	u, err := c.Fleet.Unit(name)
-	if err != nil {
+	switch {
+	case err != nil:
 		return "", fmt.Errorf("Error retrieving Unit %s: %v", name, err)
-	}
-	if suToGlobal(*u) {
+	case suToGlobal(*u):
 		return "", fmt.Errorf("Unable to connect to global unit %s.\n", name)
-	}
-	if u == nil {
+	case u == nil:
 		return "", fmt.Errorf("Unit %s does not exist.\n", name)
-	} else if u.CurrentState == "" {
+	case u.CurrentState == "":
 		return "", fmt.Errorf("Unit %s does not appear to be running.\n", name)
 	}
 

deisctl/backend/fleet/status.go

@@ -20,18 +20,17 @@ func (c *FleetClient) Status(target string) (err error) {
 // printUnitStatus displays the systemd status for a given unit
 func (c *FleetClient) printUnitStatus(name string) int {
 	u, err := c.Fleet.Unit(name)
-	if suToGlobal(*u) {
+	switch {
+	case suToGlobal(*u):
 		fmt.Fprintf(c.errWriter, "Unable to get status for global unit %s. Check the status on the host using systemctl.\n", name)
 		return 1
-	}
-	if err != nil {
+	case err != nil:
 		fmt.Fprintf(c.errWriter, "Error retrieving Unit %s: %v\n", name, err)
 		return 1
-	}
-	if u == nil {
+	case u == nil:
 		fmt.Fprintf(c.errWriter, "Unit %s does not exist.\n", name)
 		return 1
-	} else if u.CurrentState == "" {
+	case u.CurrentState == "":
 		fmt.Fprintf(c.errWriter, "Unit %s does not appear to be running.\n", name)
 		return 1
 	}

deisctl/client/client.go

@@ -92,13 +92,14 @@ Examples:
 	var action string
 	var key []string
 
-	if args["set"] == true {
+	switch {
+	case args["set"] == true:
 		action = "set"
 		key = args["<key=val>"].([]string)
-	} else if args["rm"] == true {
+	case args["rm"] == true:
 		action = "rm"
 		key = args["<key>"].([]string)
-	} else {
+	default:
 		action = "get"
 		key = args["<key>"].([]string)
 	}

deisctl/cmd/cmd.go

@@ -70,14 +70,15 @@ func Start(targets []string, b backend.Backend) error {
 
 	// if target is platform, install all services
 	if len(targets) == 1 {
-		if targets[0] == PlatformCommand {
+		switch targets[0] {
+		case PlatformCommand:
 			return StartPlatform(b, false)
-		} else if targets[0] == StatelessPlatformCommand {
+		case StatelessPlatformCommand:
 			return StartPlatform(b, true)
-		} else if targets[0] == swarm {
-			return StartSwarm(b)
-		} else if targets[0] == mesos {
+		case mesos:
 			return StartMesos(b)
+		case swarm:
+			return StartSwarm(b)
 		}
 	}
 	var wg sync.WaitGroup
@@ -170,14 +171,15 @@ func Stop(targets []string, b backend.Backend) error {
 
 	// if target is platform, stop all services
 	if len(targets) == 1 {
-		if targets[0] == PlatformCommand {
+		switch targets[0] {
+		case PlatformCommand:
 			return StopPlatform(b, false)
-		} else if targets[0] == StatelessPlatformCommand {
+		case StatelessPlatformCommand:
 			return StopPlatform(b, true)
-		} else if targets[0] == swarm {
-			return StopSwarm(b)
-		} else if targets[0] == mesos {
+		case mesos:
 			return StopMesos(b)
+		case swarm:
+			return StopSwarm(b)
 		}
 	}
 
@@ -268,14 +270,15 @@ func Install(targets []string, b backend.Backend, checkKeys func() error) error
 
 	// if target is platform, install all services
 	if len(targets) == 1 {
-		if targets[0] == PlatformCommand {
+		switch targets[0] {
+		case PlatformCommand:
 			return InstallPlatform(b, checkKeys, false)
-		} else if targets[0] == StatelessPlatformCommand {
+		case StatelessPlatformCommand:
 			return InstallPlatform(b, checkKeys, true)
-		} else if targets[0] == swarm {
-			return InstallSwarm(b)
-		} else if targets[0] == mesos {
+		case mesos:
 			return InstallMesos(b)
+		case swarm:
+			return InstallSwarm(b)
 		}
 	}
 	var wg sync.WaitGroup
@@ -325,14 +328,15 @@ func installDefaultServices(b backend.Backend, stateless bool, wg *sync.WaitGrou
 // After Uninstall, the components will be unavailable until Install is called.
 func Uninstall(targets []string, b backend.Backend) error {
 	if len(targets) == 1 {
-		if targets[0] == PlatformCommand {
+		switch targets[0] {
+		case PlatformCommand:
 			return UninstallPlatform(b, false)
-		} else if targets[0] == StatelessPlatformCommand {
+		case StatelessPlatformCommand:
 			return UninstallPlatform(b, true)
-		} else if targets[0] == swarm {
-			return UnInstallSwarm(b)
-		} else if targets[0] == mesos {
+		case mesos:
 			return UninstallMesos(b)
+		case swarm:
+			return UnInstallSwarm(b)
 		}
 	}
 

deisctl/cmd/cmd_test.go

@@ -36,11 +36,12 @@ func (backend *backendStub) Stop(targets []string, wg *sync.WaitGroup, out, ew i
 	backend.stoppedUnits = append(backend.stoppedUnits, targets...)
 }
 func (backend *backendStub) Scale(component string, num int, wg *sync.WaitGroup, out, ew io.Writer) {
-	if component == "router" && num == 3 {
+	switch {
+	case component == "router" && num == 3:
 		backend.expected = true
-	} else if component == "registry" && num == 4 {
+	case component == "registry" && num == 4:
 		backend.expected = true
-	} else {
+	default:
 		backend.expected = false
 	}
 }

deisctl/config/config.go

@@ -54,11 +54,12 @@ func doConfig(target string, action string, key []string, client Client, w io.Wr
 	var vals []string
 	var err error
 
-	if action == "set" {
-		vals, err = doConfigSet(client, rootPath, key)
-	} else if action == "rm" {
+	switch action {
+	case "rm":
 		vals, err = doConfigRm(client, rootPath, key)
-	} else {
+	case "set":
+		vals, err = doConfigSet(client, rootPath, key)
+	default:
 		vals, err = doConfigGet(client, rootPath, key)
 	}
 	if err != nil {