Merge pull request #448 from crosbymichael/nsinit-usability

nsinit usability improvements

nsinit/exec.go

@@ -24,8 +24,7 @@ var execCommand = cli.Command{
 	Flags: append([]cli.Flag{
 		cli.BoolFlag{Name: "tty,t", Usage: "allocate a TTY to the container"},
 		cli.StringFlag{Name: "id", Value: "nsinit", Usage: "specify the ID for a container"},
-		cli.StringFlag{Name: "config", Value: "container.json", Usage: "path to the configuration file"},
+		cli.StringFlag{Name: "config", Value: "", Usage: "path to the configuration file"},
-		cli.BoolFlag{Name: "create", Usage: "create the container's configuration on the fly with arguments"},
 		cli.StringFlag{Name: "user,u", Value: "root", Usage: "set the user, uid, and/or gid for the process"},
 		cli.StringFlag{Name: "cwd", Value: "", Usage: "set the current working dir"},
 		cli.StringSliceFlag{Name: "env", Value: standardEnvironment, Usage: "set environment variables for the process"},

nsinit/main.go

@@ -14,7 +14,7 @@ func main() {
 	app.Author = "libcontainer maintainers"
 	app.Flags = []cli.Flag{
 		cli.StringFlag{Name: "root", Value: ".", Usage: "root directory for containers"},
-		cli.StringFlag{Name: "log-file", Value: "nsinit-debug.log", Usage: "set the log file to output logs to"},
+		cli.StringFlag{Name: "log-file", Value: "", Usage: "set the log file to output logs to"},
 		cli.BoolFlag{Name: "debug", Usage: "enable debug output in the logs"},
 	}
 	app.Commands = []cli.Command{

nsinit/utils.go

@@ -11,20 +11,20 @@ import (
 )
 
 func loadConfig(context *cli.Context) (*configs.Config, error) {
-	if context.Bool("create") {
+	if path := context.String("config"); path != "" {
-		config := getTemplate()
+		f, err := os.Open(path)
-		modify(config, context)
+		if err != nil {
+			return nil, err
+		}
+		defer f.Close()
+		var config *configs.Config
+		if err := json.NewDecoder(f).Decode(&config); err != nil {
+			return nil, err
+		}
 		return config, nil
 	}
-	f, err := os.Open(context.String("config"))
+	config := getTemplate()
-	if err != nil {
+	modify(config, context)
-		return nil, err
-	}
-	defer f.Close()
-	var config *configs.Config
-	if err := json.NewDecoder(f).Decode(&config); err != nil {
-		return nil, err
-	}
 	return config, nil
 }