Add "--private-key" option for "keypair create"

Aim to specify the private key file to save when keypair
is created. That is a convenient way to save private key
in OSC interactive mode, avoid to copy CLI output, then
paste it into file.

Change-Id: I119d2f2a3323d17ecbe3de4e27f35e1ceef6e0a5
Closes-Bug: #1549410

doc/source/command-objects/keypair.rst

@@ -18,13 +18,18 @@ Create new public or private key for server ssh access
 .. code:: bash
 
     openstack keypair create
-        [--public-key <file>]
+        [--public-key <file> | --private-key <file>]
         <name>
 
 .. option:: --public-key <file>
 
     Filename for public key to add. If not used, creates a private key.
 
+.. option:: --private-key <file>
+
+    Filename for private key to save. If not used, print private key in
+    console.
+
 .. describe:: <name>
 
     New public or private key name

openstackclient/compute/v2/keypair.py

@@ -41,12 +41,19 @@ class CreateKeypair(command.ShowOne):
             metavar='<name>',
             help=_("New public or private key name")
         )
-        parser.add_argument(
+        key_group = parser.add_mutually_exclusive_group()
+        key_group.add_argument(
             '--public-key',
             metavar='<file>',
             help=_("Filename for public key to add. If not used, "
                    "creates a private key.")
         )
+        key_group.add_argument(
+            '--private-key',
+            metavar='<file>',
+            help=_("Filename for private key to save. If not used, "
+                   "print private key in console.")
+        )
         return parser
 
     def take_action(self, parsed_args):
@@ -69,13 +76,31 @@ class CreateKeypair(command.ShowOne):
             public_key=public_key,
         )
 
+        private_key = parsed_args.private_key
+        # Save private key into specified file
+        if private_key:
+            try:
+                with io.open(
+                        os.path.expanduser(parsed_args.private_key), 'w+'
+                ) as p:
+                    p.write(keypair.private_key)
+            except IOError as e:
+                msg = _("Key file %(private_key)s can not be saved: "
+                        "%(exception)s")
+                raise exceptions.CommandError(
+                    msg % {"private_key": parsed_args.private_key,
+                           "exception": e}
+                )
         # NOTE(dtroyer): how do we want to handle the display of the private
         #                key when it needs to be communicated back to the user
         #                For now, duplicate nova keypair-add command output
         info = {}
-        if public_key:
+        if public_key or private_key:
             info.update(keypair._info)
-            del info['public_key']
+            if 'public_key' in info:
+                del info['public_key']
+            if 'private_key' in info:
+                del info['private_key']
             return zip(*sorted(six.iteritems(info)))
         else:
             sys.stdout.write(keypair.private_key)

openstackclient/tests/functional/compute/v2/test_keypair.py

@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import json
 import tempfile
 
 from openstackclient.tests.functional import base
@@ -100,6 +101,26 @@ class KeypairTests(KeypairBase):
             )
             self.assertIn('tmpkey', raw_output)
 
+    def test_keypair_create_private_key(self):
+        """Test for create keypair with --private-key option.
+
+        Test steps:
+        1) Create keypair with private key file
+        2) Delete keypair
+        """
+        with tempfile.NamedTemporaryFile() as f:
+            cmd_output = json.loads(self.openstack(
+                'keypair create -f json --private-key %s tmpkey' % f.name,
+            ))
+            self.addCleanup(self.openstack, 'keypair delete tmpkey')
+            self.assertEqual('tmpkey', cmd_output.get('name'))
+            self.assertIsNotNone(cmd_output.get('user_id'))
+            self.assertIsNotNone(cmd_output.get('fingerprint'))
+            pk_content = f.read()
+            self.assertInOutput('-----BEGIN RSA PRIVATE KEY-----', pk_content)
+            self.assertRegex(pk_content, "[0-9A-Za-z+/]+[=]{0,3}\n")
+            self.assertInOutput('-----END RSA PRIVATE KEY-----', pk_content)
+
     def test_keypair_create(self):
         """Test keypair create command.
 

openstackclient/tests/unit/compute/v2/test_keypair.py

@@ -15,6 +15,7 @@
 
 import mock
 from mock import call
+import uuid
 
 from osc_lib import exceptions
 from osc_lib import utils
@@ -115,6 +116,36 @@ class TestKeypairCreate(TestKeypair):
             self.assertEqual(self.columns, columns)
             self.assertEqual(self.data, data)
 
+    def test_keypair_create_private_key(self):
+        tmp_pk_file = '/tmp/kp-file-' + uuid.uuid4().hex
+        arglist = [
+            '--private-key', tmp_pk_file,
+            self.keypair.name,
+        ]
+        verifylist = [
+            ('private_key', tmp_pk_file),
+            ('name', self.keypair.name)
+        ]
+
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        with mock.patch('io.open') as mock_open:
+            mock_open.return_value = mock.MagicMock()
+            m_file = mock_open.return_value.__enter__.return_value
+
+            columns, data = self.cmd.take_action(parsed_args)
+
+            self.keypairs_mock.create.assert_called_with(
+                self.keypair.name,
+                public_key=None
+            )
+
+            mock_open.assert_called_once_with(tmp_pk_file, 'w+')
+            m_file.write.assert_called_once_with(self.keypair.private_key)
+
+            self.assertEqual(self.columns, columns)
+            self.assertEqual(self.data, data)
+
 
 class TestKeypairDelete(TestKeypair):
 

releasenotes/notes/bug-1549410-8df3a4b12fe13ffa.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    Add ``--private-key`` option for ``keypair create`` command to specify the
+    private key file to save when a keypair is created, removing the need to
+    copy the output and paste it into a new file. This is a convenient way
+    to save private key in OSC interactive mode.
+    [Bug `1549410 <https://bugs.launchpad.net/python-openstackclient/+bug/1549410>`_]