use plain-text file for launchpad credentials

Authenticating to use launchpad now defaults to an encrypted keyring,
which requires the user to enter a keyring password
interactively. Enable using a plain-text file explicitly or via an
environment variable to bypass this to improve automation.

Change-Id: Ifed22f7c178b1e62e7b5e95d0f8810633ba46fb1

process_bugs.py

@@ -20,18 +20,18 @@
 from __future__ import print_function
 import argparse
 
-import launchpadlib.launchpad
 import lazr.restfulclient.errors
 
+from releasetools import launchpadutils
+
 # Parameters
 parser = argparse.ArgumentParser(description="Change Launchpad bugs in bulk")
 parser.add_argument('projectname', help='The project to act on')
+launchpadutils.add_cli_arguments(parser)
 bugsfrom = parser.add_mutually_exclusive_group()
 bugsfrom.add_argument('--status', default='Fix Committed',
                       help='All bugs with that status')
 bugsfrom.add_argument('--milestone', help='All open bugs from this milestone')
-parser.add_argument("--test", action='store_const', const='staging',
-                    default='production', help='Use LP staging server to test')
 parser.add_argument('--settarget',
                     help='ACTION: set the milestone to specified target')
 parser.add_argument('--fixrelease', action='store_true',
@@ -42,7 +42,7 @@ args = parser.parse_args()
 
 # Connect to Launchpad
 print("Connecting to Launchpad...")
-launchpad = launchpadlib.launchpad.Launchpad.login_with('openstack-releasing', args.test)
+launchpad = launchpadutils.login(args)
 
 # Retrieve bugs
 print("Retrieving project...")

releasetools/cmds/add_comment.py

@@ -20,9 +20,10 @@
 from __future__ import print_function
 import argparse
 
-import launchpadlib.launchpad
 import lazr.restfulclient.errors
 
+from releasetools import launchpadutils
+
 
 def main():
     # Parameters
@@ -31,15 +32,14 @@ def main():
                         default='Comment added by add_comment')
     parser.add_argument('--content', help='The comment content',
                         default='Comment added by add_comment')
-    parser.add_argument("--test", action='store_const', const='staging',
-                        default='production', help='Use LP staging server to test')
-    parser.add_argument('bugs', type=int, nargs='+', help='Bugs to add comment to')
+    launchpadutils.add_cli_arguments(parser)
+    parser.add_argument('bugs', type=int, nargs='+',
+                        help='Bugs to add comment to')
     args = parser.parse_args()
 
     # Connect to Launchpad
     print("Connecting to Launchpad...")
-    launchpad = launchpadlib.launchpad.Launchpad.login_with(
-        'openstack-releasing', args.test)
+    launchpad = launchpadutils.login(args)
 
     # Add comment
     for bugid in args.bugs:

releasetools/cmds/launchpad_login.py

@@ -19,9 +19,10 @@
 from __future__ import print_function
 from __future__ import unicode_literals
 
+import argparse
 import sys
 
-import launchpadlib.launchpad
+from releasetools import launchpadutils
 
 
 def abort(code, errmsg):
@@ -30,9 +31,13 @@ def abort(code, errmsg):
 
 
 def main():
+    parser = argparse.ArgumentParser(description="login to launchpad")
+    launchpadutils.add_cli_arguments(parser)
+    args = parser.parse_args()
+
     # Connect to LP
     print("connecting to launchpad")
     try:
-        launchpadlib.launchpad.Launchpad.login_with('openstack-releasing', 'production')
+        launchpadutils.login(args)
     except Exception as error:
         abort(2, 'Could not connect to Launchpad: ' + str(error))

releasetools/launchpadutils.py

@@ -0,0 +1,55 @@
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import os.path
+
+import launchpadlib.launchpad
+
+
+def add_cli_arguments(parser):
+    """Add command line arguments for launchpad to the argument parser
+
+    Given an argparse.ArgumentParser instance, add options
+    to let the user control how they interact with launchpad.
+    """
+    lp_grp = parser.add_argument_group('launchpad')
+    lp_grp.add_argument(
+        "--test",
+        action='store_const',
+        dest='lp_service_root',
+        const='staging',
+        default='production',
+        help='Use LP staging server to test',
+    )
+    lp_grp.add_argument(
+        '--credentials-file', '-c',
+        dest='lp_creds_file',
+        default=os.environ.get('LP_CREDS_FILE'),
+        help=('plain-text credentials file, '
+              'defaults to value of $LP_CREDS_FILE'),
+    )
+
+
+def login(parsed_args):
+    """Return a live launchpad connection
+
+    Given the results of parsing command line arguments,
+    open a connection to launchpad using the values
+    specified by the user and return the handle.
+    """
+    return launchpadlib.launchpad.Launchpad.login_with(
+        application_name='openstack-releasing',
+        service_root=parsed_args.lp_service_root,
+        credentials_file=parsed_args.lp_creds_file,
+    )