get-nodes-tests.patch

diff --git a/bin/swift-get-nodes b/bin/swift-get-nodes
index f2e3046..0e9eea9 100755
--- a/bin/swift-get-nodes
+++ b/bin/swift-get-nodes
@@ -19,7 +19,8 @@ import os
 from optparse import OptionParser
 
 from swift.common.ring import Ring
-from swift.cli.info import print_item_locations, InfoSystemExit
+from swift.cli.info import (parse_get_node_args, print_item_locations,
+                            InfoSystemExit)
 
 
 if __name__ == '__main__':
@@ -50,32 +51,17 @@ if __name__ == '__main__':
                       dest='swift_dir', help='Path to swift directory')
     options, args = parser.parse_args()
 
-    # swift-get-nodes -P nada -p 1
-    if len(args) == 0:
-        if not options.policy_name or not options.partition:
-            sys.exit(parser.print_help())
-    elif len(args) > 4 or len(args) == 0:
-        sys.exit(parser.print_help())
-
-    # Parse single path arg, as noted in above help text.
-    # if len(args) == 1 and options.policy_name and '/' in args[0]:
-    if len(args) == 1 and not args[0].endswith('ring.gz'):
-        path = args[0].lstrip('/')
-        args = [p for p in path.split('/', 2) if p]
-    if len(args) == 2 and '/' in args[1]:
-        path = args[1].lstrip('/')
-        args = [args[0]] + [p for p in path.split('/', 2) if p]
-
-    ring = None
-    ring_name = None
+    try:
+        ring_path, args = parse_get_node_args(options, args)
+    except InfoSystemExit as e:
+        sys.exit(parser.print_help() + '\nERROR: %s' % e)
 
-    if options.policy_name is None and len(args) >= 1:
-        if os.path.exists(args[0]) and args[0].endswith('ring.gz'):
-            ring_name = args[0].rsplit('/', 1)[-1].split('.', 1)[0]
-            ring = Ring(args[0])
-            args.pop(0)
-        else:
-            sys.exit('Ring file does not exist')
+    ring = ring_name = None
+    if ring_path:
+        # it's really strange that print_items wants both of these args, but
+        # can also calculate the ring from the policy_name kwarg?!
+        ring_name = ring_path.rsplit('/', 1)[-1].split('.', 1)[0]
+        ring = Ring(ring_path)
 
     try:
         print_item_locations(ring, ring_name, *args, **vars(options))
diff --git a/swift/cli/info.py b/swift/cli/info.py
index c5dda94..4c8dc3b 100644
--- a/swift/cli/info.py
+++ b/swift/cli/info.py
@@ -37,6 +37,39 @@ class InfoSystemExit(Exception):
     pass
 
 
+def parse_get_node_args(options, args):
+    """
+    Parse the get_nodes commandline args
+
+    :returns: a tuple, (ring_path, args)
+    """
+    # swift-get-nodes -P nada -p 1
+    if len(args) == 0:
+        if not options.policy_name or not options.partition:
+            raise InfoSystemExit('Need to specify policy_name or <ring.gz>')
+    elif len(args) > 4 or len(args) == 0:
+        raise InfoSystemExit('Invalid arguments')
+
+    # Parse single path arg, as noted in above help text.
+    # if len(args) == 1 and options.policy_name and '/' in args[0]:
+    if len(args) == 1 and not args[0].endswith('ring.gz'):
+        path = args[0].lstrip('/')
+        args = [p for p in path.split('/', 2) if p]
+    if len(args) == 2 and '/' in args[1]:
+        path = args[1].lstrip('/')
+        args = [args[0]] + [p for p in path.split('/', 2) if p]
+
+    ring_path = None
+
+    if options.policy_name is None and len(args) >= 1:
+        if os.path.exists(args[0]) and args[0].endswith('ring.gz'):
+            ring_path = args.pop(0)
+        else:
+            raise InfoSystemExit('Ring file does not exist')
+
+    return ring_path, args
+
+
 def print_ring_locations(ring, datadir, account, container=None, obj=None,
                          tpart=None, all_nodes=False, policy_index=None):
     """
diff --git a/test/unit/cli/test_info.py b/test/unit/cli/test_info.py
index a97362d..405f23d 100644
--- a/test/unit/cli/test_info.py
+++ b/test/unit/cli/test_info.py
@@ -12,6 +12,7 @@
 
 """Tests for swift.cli.info"""
 
+from argparse import Namespace
 import os
 import unittest
 import mock
@@ -26,7 +27,7 @@ from swift.common.swob import Request
 from swift.common.storage_policy import StoragePolicy, POLICIES
 from swift.cli.info import print_db_info_metadata, print_ring_locations, \
     print_info, print_obj_metadata, print_obj, InfoSystemExit, \
-    print_item_locations
+    print_item_locations, parse_get_node_args
 from swift.account.server import AccountController
 from swift.container.server import ContainerController
 from swift.obj.diskfile import write_metadata
@@ -476,6 +477,34 @@ No user metadata found in db file''' % POLICIES[0].name
         else:
             self.fail("Expected an InfoSystemExit exception to be raised")
 
+    def test_parse_get_node_args(self):
+        # -P test a c o
+        options = Namespace(policy_name='test')
+        args = 'a c o'
+        ring_path, args = parse_get_node_args(options, args.split())
+        self.assertEqual(ring_path, None)
+        self.assertEqual(args, ['a', 'c', 'o'])
+        # objects.ring.gz /a/c/o
+        options = Namespace(policy_name=None)
+        args = 'object.ring.gz /a/c/o'
+        with mock.patch('swift.cli.info.os.path.exists', lambda p: True):
+            ring_path, args = parse_get_node_args(options, args.split())
+        self.assertEqual(ring_path, 'object.ring.gz')
+        self.assertEqual(args, ['a', 'c', 'o'])
+        # objects.ring.gz a c o
+        options = Namespace(policy_name=None)
+        args = 'object.ring.gz a c o'
+        with mock.patch('swift.cli.info.os.path.exists', lambda p: True):
+            ring_path, args = parse_get_node_args(options, args.split())
+        self.assertEqual(ring_path, 'object.ring.gz')
+        self.assertEqual(args, ['a', 'c', 'o'])
+        # -P test -p 1
+        options = Namespace(policy_name='test', partition='1')
+        args = ''
+        ring_path, args = parse_get_node_args(options, args.split())
+        self.assertEqual(ring_path, None)
+        self.assertEqual(args, [])
+
 
 class TestPrintObj(TestCliInfoBase):