Backends can receive arguments

swarmd/swarmd.go

@@ -6,6 +6,8 @@ import (
 	"github.com/docker/swarmd/backends"
 	"github.com/dotcloud/docker/api/server"
 	"github.com/dotcloud/docker/engine"
+	"github.com/flynn/go-shlex"
+	"io"
 	"os"
 	"strings"
 	"time"
@@ -36,10 +38,13 @@ func cmdDaemon(c *cli.Context) {
 	// multiplexes across all backends (with routing / filtering
 	// logic along the way).
 	back := backends.New()
-	backendName := c.String("backend")
-	fmt.Printf("Loading backend '%s'\n", backendName)
-	if err := back.Job(backendName).Run(); err != nil {
-		Fatalf("%s: %v\n", backendName, err)
+	bName, bArgs, err := parseCmd(c.String("backend"))
+	if err != nil {
+		Fatalf("%v", err)
+	}
+	fmt.Printf("---> Loading backend '%s'\n", strings.Join(append([]string{bName}, bArgs...), " "))
+	if err := back.Job(bName, bArgs...).Run(); err != nil {
+		Fatalf("%s: %v\n", bName, err)
 	}
 
 	// Register the API entrypoint
@@ -75,6 +80,28 @@ func cmdDaemon(c *cli.Context) {
 	<-make(chan struct{})
 }
 
+func parseCmd(txt string) (string, []string, error) {
+	l, err := shlex.NewLexer(strings.NewReader(txt))
+	if err != nil {
+		return "", nil, err
+	}
+	var cmd []string
+	for {
+		word, err := l.NextWord()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return "", nil, err
+		}
+		cmd = append(cmd, word)
+	}
+	if len(cmd) == 0 {
+		return "", nil, fmt.Errorf("parse error: empty command")
+	}
+	return cmd[0], cmd[1:], nil
+}
+
 func Fatalf(msg string, args ...interface{}) {
 	if !strings.HasSuffix(msg, "\n") {
 		msg = msg + "\n"