Add support for keypair-add command reading public key from stdin

If given filename is `-` for `--pub-key` option, reads public key
from stdin.

  $ cat id_rsa.pub | nova keypair-add --pub-key - keyname

Change-Id: Ib6dfe5a7b08d588868a923defb9ddd15fc28e01f
Closes-Bug: #1333476

novaclient/tests/unit/v2/test_shell.py

@@ -2304,6 +2304,14 @@ class ShellTest(utils.TestCase):
             'POST', '/os-keypairs', {
                 'keypair': {'public_key': 'FAKE_PUBLIC_KEY', 'name': 'test'}})
 
+    def test_keypair_stdin(self):
+        with mock.patch('sys.stdin', six.StringIO('FAKE_PUBLIC_KEY')):
+            self.run_command('keypair-add --pub-key - test')
+            self.assert_called(
+                'POST', '/os-keypairs', {
+                    'keypair':
+                        {'public_key': 'FAKE_PUBLIC_KEY', 'name': 'test'}})
+
     def test_keypair_list(self):
         self.run_command('keypair-list')
         self.assert_called('GET', '/os-keypairs')

novaclient/v2/shell.py

@@ -2865,13 +2865,17 @@ def do_keypair_add(cs, args):
     pub_key = args.pub_key
 
     if pub_key:
-        try:
-            with open(os.path.expanduser(pub_key)) as f:
-                pub_key = f.read()
-        except IOError as e:
-            raise exceptions.CommandError(_("Can't open or read '%(key)s': "
-                                            "%(exc)s") % {'key': pub_key,
-                                                          'exc': e})
+        if pub_key == '-':
+            pub_key = sys.stdin.read()
+        else:
+            try:
+                with open(os.path.expanduser(pub_key)) as f:
+                    pub_key = f.read()
+            except IOError as e:
+                raise exceptions.CommandError(
+                    _("Can't open or read '%(key)s': %(exc)s")
+                    % {'key': pub_key, 'exc': e}
+                )
 
     keypair = cs.keypairs.create(name, pub_key)