joyent/node-triton#193 triton ssh ... can crash if the instance image has no tags

Reviewed by: Josh Wilsdon <josh@wilsdon.ca>
Approved by: Josh Wilsdon <josh@wilsdon.ca>

CHANGES.md

@@ -7,6 +7,9 @@ Known issues:
 
 ## not yet released
 
+- [joyent/node-triton#193] Fix possible CLI crash with `triton ssh ...` if the
+  instance's image doesn't have any tags.
+
 ## 5.2.0
 
 - [joyent/node-triton#197] Create triton image export command

lib/do_instance/do_ssh.js

@@ -5,7 +5,7 @@
  */
 
 /*
- * Copyright 2016 Joyent, Inc.
+ * Copyright 2017 Joyent, Inc.
  *
  * `triton instance ssh ...`
  */
@@ -76,7 +76,7 @@ function do_ssh(subcmd, opts, args, callback) {
                  * This is a convention as seen on Joyent's
                  * "ubuntu-certified" KVM images.
                  */
-                if (image.tags.default_user) {
+                if (image.tags && image.tags.default_user) {
                     user = image.tags.default_user;
                 } else {
                     user = 'root';