Returns exit code 3 on pre-create check

Signed-off-by: Jean-Laurent de Morlhon <jeanlaurent@morlhon.net>

commands/commands.go

@@ -12,6 +12,7 @@ import (
 	"github.com/docker/machine/libmachine/crashreport"
 	"github.com/docker/machine/libmachine/host"
 	"github.com/docker/machine/libmachine/log"
+	"github.com/docker/machine/libmachine/mcnerror"
 	"github.com/docker/machine/libmachine/mcnutils"
 	"github.com/docker/machine/libmachine/persist"
 	"github.com/docker/machine/libmachine/ssh"
@@ -122,7 +123,11 @@ func runCommand(command func(commandLine CommandLine, api libmachine.API) error)
 				crashReporter.Send(crashErr)
 			}
 
-			osExit(1)
+			if _, ok := err.(mcnerror.ErrDuringPreCreate); ok {
+				osExit(3)
+			} else {
+				osExit(1)
+			}
 		}
 	}
 }

commands/commands_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/docker/machine/libmachine/crashreport"
 	"github.com/docker/machine/libmachine/host"
 	"github.com/docker/machine/libmachine/hosttest"
+	"github.com/docker/machine/libmachine/mcnerror"
 	"github.com/docker/machine/libmachine/state"
 	"github.com/stretchr/testify/assert"
 )
@@ -191,3 +192,37 @@ func TestSendCrashReport(t *testing.T) {
 		assert.Equal(t, test.sent, mockCrashReporter.sent, test.description)
 	}
 }
+
+func TestReturnExitCode1onError(t *testing.T) {
+	command := func(commandLine CommandLine, api libmachine.API) error {
+		return errors.New("foo is not bar")
+	}
+
+	exitCode := checkErrorCodeForCommand(command)
+
+	assert.Equal(t, exitCode, 1)
+}
+
+func TestReturnExitCode3onErrorDuringPreCreate(t *testing.T) {
+	command := func(commandLine CommandLine, api libmachine.API) error {
+		return mcnerror.ErrDuringPreCreate{errors.New("foo is not bar")}
+	}
+
+	exitCode := checkErrorCodeForCommand(command)
+
+	assert.Equal(t, exitCode, 3)
+}
+
+func checkErrorCodeForCommand(command func(commandLine CommandLine, api libmachine.API) error) int {
+	var exitCode int
+
+	defer func(fnOsExit func(code int)) { osExit = fnOsExit }(osExit)
+	osExit = func(code int) {
+		exitCode = code
+	}
+
+	context := cli.NewContext(cli.NewApp(), &flag.FlagSet{}, nil)
+	runCommand(command)(context)
+
+	return exitCode
+}

libmachine/libmachine.go

@@ -19,6 +19,7 @@ import (
 	"github.com/docker/machine/libmachine/engine"
 	"github.com/docker/machine/libmachine/host"
 	"github.com/docker/machine/libmachine/log"
+	"github.com/docker/machine/libmachine/mcnerror"
 	"github.com/docker/machine/libmachine/mcnutils"
 	"github.com/docker/machine/libmachine/persist"
 	"github.com/docker/machine/libmachine/provision"
@@ -124,7 +125,7 @@ func (api *Client) Create(h *host.Host) error {
 	log.Info("Running pre-create checks...")
 
 	if err := h.Driver.PreCreateCheck(); err != nil {
-		return fmt.Errorf("Error with pre-create check: %s", err)
+		return mcnerror.ErrDuringPreCreate{err}
 	}
 
 	if err := api.Save(h); err != nil {

libmachine/mcnerror/errors.go

@@ -24,3 +24,11 @@ type ErrHostAlreadyExists struct {
 func (e ErrHostAlreadyExists) Error() string {
 	return fmt.Sprintf("Host already exists: %q", e.Name)
 }
+
+type ErrDuringPreCreate struct {
+	Cause error
+}
+
+func (e ErrDuringPreCreate) Error() string {
+	return fmt.Sprintf("Error with pre-create check: %q", e.Cause)
+}