Add sync mode.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

main.go

@@ -66,6 +66,11 @@ func main() {
 			EnvVar: "PLUGIN_PORT,SSH_PORT",
 			Value:  22,
 		},
+		cli.BoolFlag{
+			Name:   "sync",
+			Usage:  "sync mode",
+			EnvVar: "PLUGIN_SYNC",
+		},
 		cli.DurationFlag{
 			Name:   "timeout,t",
 			Usage:  "connection timeout",
@@ -195,6 +200,7 @@ func run(c *cli.Context) error {
 			Secrets:        c.StringSlice("secrets"),
 			Envs:           c.StringSlice("envs"),
 			Debug:          c.Bool("debug"),
+			Sync:           c.Bool("sync"),
 			Proxy: easyssh.DefaultConfig{
 				Key:      c.String("proxy.ssh-key"),
 				KeyPath:  c.String("proxy.key-path"),

plugin.go

@@ -34,6 +34,7 @@ type (
 		Envs           []string
 		Proxy          easyssh.DefaultConfig
 		Debug          bool
+		Sync           bool
 	}
 
 	// Plugin structure
@@ -42,34 +43,7 @@ type (
 	}
 )
 
-func (p Plugin) log(host string, message ...interface{}) {
+func (p Plugin) exec(host string, wg *sync.WaitGroup, errChannel chan error) {
-	if count := len(p.Config.Host); count == 1 {
-		fmt.Printf("%s", fmt.Sprintln(message...))
-	} else {
-		fmt.Printf("%s: %s", host, fmt.Sprintln(message...))
-	}
-}
-
-// Exec executes the plugin.
-func (p Plugin) Exec() error {
-	if len(p.Config.Host) == 0 && len(p.Config.UserName) == 0 {
-		return fmt.Errorf(missingHostOrUser)
-	}
-
-	if len(p.Config.Key) == 0 && len(p.Config.Password) == 0 && len(p.Config.KeyPath) == 0 {
-		return fmt.Errorf(missingPasswordOrKey)
-	}
-
-	if len(p.Config.Key) != 0 && len(p.Config.Password) != 0 {
-		return fmt.Errorf(setPasswordandKey)
-	}
-
-	wg := sync.WaitGroup{}
-	wg.Add(len(p.Config.Host))
-	errChannel := make(chan error, 1)
-	finished := make(chan bool, 1)
-	for _, host := range p.Config.Host {
-		go func(host string) {
 	// Create MakeConfig instance with remote username, server address and path to private key.
 	ssh := &easyssh.MakeConfig{
 		Server:   host,
@@ -141,13 +115,48 @@ func (p Plugin) Exec() error {
 	}
 
 	wg.Done()
-		}(host)
 }
 
+func (p Plugin) log(host string, message ...interface{}) {
+	if count := len(p.Config.Host); count == 1 {
+		fmt.Printf("%s", fmt.Sprintln(message...))
+	} else {
+		fmt.Printf("%s: %s", host, fmt.Sprintln(message...))
+	}
+}
+
+// Exec executes the plugin.
+func (p Plugin) Exec() error {
+	if len(p.Config.Host) == 0 && len(p.Config.UserName) == 0 {
+		return fmt.Errorf(missingHostOrUser)
+	}
+
+	if len(p.Config.Key) == 0 && len(p.Config.Password) == 0 && len(p.Config.KeyPath) == 0 {
+		return fmt.Errorf(missingPasswordOrKey)
+	}
+
+	if len(p.Config.Key) != 0 && len(p.Config.Password) != 0 {
+		return fmt.Errorf(setPasswordandKey)
+	}
+
+	wg := sync.WaitGroup{}
+	wg.Add(len(p.Config.Host))
+	errChannel := make(chan error, 1)
+	finished := make(chan bool, 1)
+	for _, host := range p.Config.Host {
+		if p.Config.Sync {
+			p.exec(host, &wg, errChannel)
+		} else {
+			go p.exec(host, &wg, errChannel)
+		}
+	}
+
+	if !p.Config.Sync {
 		go func() {
 			wg.Wait()
 			close(finished)
 		}()
+	}
 
 	select {
 	case <-finished:

plugin_test.go

@@ -256,3 +256,20 @@ func TestSetENV(t *testing.T) {
 	err := plugin.Exec()
 	assert.Nil(t, err)
 }
+
+func TestSyncMode(t *testing.T) {
+	plugin := Plugin{
+		Config: Config{
+			Host:           []string{"localhost", "127.0.0.1"},
+			UserName:       "drone-scp",
+			Port:           22,
+			KeyPath:        "./tests/.ssh/id_rsa",
+			Script:         []string{"whoami", "for i in {1..3}; do echo ${i}; sleep 1; done", "echo 'done'"},
+			CommandTimeout: 60,
+			Sync:           true,
+		},
+	}
+
+	err := plugin.Exec()
+	assert.Nil(t, err)
+}