Merge pull request #15 from ktock/exec-mountroot-default

Add mountroot default value

Author: ktock

README.md

@@ -263,7 +263,7 @@ If `ARGS` isn't provided, `/bin/sh` is used by default.
 Flags:
 
 - `--image`: Execute command in the debuger image specified by `--image` flag of [`buildg debug`](#buildg-debug). If not specified, the command is executed on the rootfs of the current step.
-- `--mountroot value`: Mountpoint to mount the rootfs of the step. ignored if `--image` isn't specified.
+- `--mountroot value`: Mountpoint to mount the rootfs of the step. ignored if `--image` isn't specified. (default: `/debugroot`)
 - `--init-state`: Execute commands in an initial state of that step (experimental)
 - `--tty`, `-t`: Allocate tty (enabled by default)
 - `-i`: Enable stdin. (FIXME: must be set with tty) (enabled by default)

exec.go

@@ -32,6 +32,7 @@ If ARGS isn't provided, "/bin/sh" is used by default.
 			cli.StringFlag{
 				Name:  "mountroot",
 				Usage: "Mountpoint to mount the rootfs of the current step. Ignored if --image isn't specified.",
+				Value: "/debugroot",
 			},
 			cli.BoolFlag{
 				Name:  "init-state",
@@ -122,12 +123,8 @@ func (h *handler) execContainer(ctx context.Context, cfg containerConfig) error
 		})
 	}
 	if cfg.image != nil {
-		mountroot := "/debugroot"
-		if cfg.mountroot != "" {
-			mountroot = cfg.mountroot
-		}
 		for i := range mounts {
-			mounts[i].Dest = filepath.Join(mountroot, mounts[i].Dest)
+			mounts[i].Dest = filepath.Join(cfg.mountroot, mounts[i].Dest)
 		}
 		mounts = append([]gwclient.Mount{
 			{