communicator/ssh: Ensure valid communicator

communicator/ssh/communicator.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"code.google.com/p/go.crypto/ssh"
 	"github.com/mitchellh/packer/packer"
+	"io"
 	"log"
 	"net"
 )
@@ -70,3 +71,11 @@ func (c *comm) Start(cmd string) (remote *packer.RemoteCommand, err error) {
 
 	return
 }
+
+func (c *comm) Upload(string, io.Reader) error {
+	return nil
+}
+
+func (c *comm) Download(string, io.Writer) error {
+	return nil
+}

communicator/ssh/communicator_test.go

@@ -3,6 +3,7 @@ package ssh
 import (
 	"bytes"
 	"code.google.com/p/go.crypto/ssh"
+	"github.com/mitchellh/packer/packer"
 	"fmt"
 	"net"
 	"strings"
@@ -132,6 +133,14 @@ func newMockLineServer(t *testing.T) string {
 	return l.Addr().String()
 }
 
+func TestCommIsCommunicator(t *testing.T) {
+	var raw interface{}
+	raw = &comm{}
+	if _, ok := raw.(packer.Communicator); !ok {
+		t.Fatalf("comm must be a communicator")
+	}
+}
+
 func TestNew_Invalid(t *testing.T) {
 	clientConfig := &ssh.ClientConfig{
 		User: "user",