cinder show with attachments is a mess

The show command currently just dumps the entire attachments
dictionary into the output which is a real mess and completely
screws up the displayed output (shell command).

There's really no reason to do this, we can just give the
attachment ID's and then when you're on the newer versions
you can do an attachment-show for all the crazy details if
you want.  Keep in mind that the list command already shows
the server-id we're attached too, but that might also be
nice from the show command rather than jumping through
multiple commands.  To try and accomodate various use cases
we'll also add an "attached_servers" field to the show command,
but you'll have to coorelate manually from there.

Change-Id: I45ac49d8d9a185c52727c5bc24a6a1323be83689
Closes-Bug: #1494941

cinderclient/tests/functional/test_cli.py

@@ -17,7 +17,8 @@ from cinderclient.tests.functional import base
 class CinderVolumeTests(base.ClientTestBase):
     """Check of base cinder volume commands."""
 
-    VOLUME_PROPERTY = ('attachments', 'availability_zone', 'bootable',
+    VOLUME_PROPERTY = ('attachment_ids', 'attached_servers',
+                       'availability_zone', 'bootable',
                        'created_at', 'description', 'encrypted', 'id',
                        'metadata', 'name', 'size', 'status',
                        'user_id', 'volume_type')

cinderclient/tests/unit/v2/fakes.py

@@ -28,7 +28,8 @@ REQUEST_ID = 'req-test-request-id'
 def _stub_volume(*args, **kwargs):
     volume = {
         "migration_status": None,
-        "attachments": [{u'server_id': u'1234'}],
+        "attachments": [{u'server_id': u'1234', u'id':
+                         u'3f88836f-adde-4296-9f6b-2c59a0bcda9a'}],
         "links": [
             {
                 "href": "http://localhost/v2/fake/volumes/1234",

cinderclient/v2/shell.py

@@ -32,6 +32,18 @@ from cinderclient import utils
 from cinderclient.v2 import availability_zones
 
 
+def _translate_attachments(info):
+    attachments = []
+    attached_servers = []
+    for attachment in info['attachments']:
+        attachments.append(attachment['id'])
+        attached_servers.append(attachment['server_id'])
+    info.pop('attachments', None)
+    info['attachment_ids'] = attachments
+    info['attached_servers'] = attached_servers
+    return info
+
+
 @utils.arg('--all-tenants',
            dest='all_tenants',
            metavar='<0|1>',
@@ -188,9 +200,10 @@ def do_show(cs, args):
         info['readonly'] = info['metadata']['readonly']
 
     info.pop('links', None)
+    info = _translate_attachments(info)
     utils.print_dict(info,
                      formatters=['metadata', 'volume_image_metadata',
-                                 'attachments'])
+                                 'attachment_ids', 'attached_servers'])
 
 
 class CheckSizeArgForCreate(argparse.Action):
@@ -340,6 +353,7 @@ def do_create(cs, args):
         info['readonly'] = info['metadata']['readonly']
 
     info.pop('links', None)
+    info = _translate_attachments(info)
     utils.print_dict(info)