Migration script: optional parameters to filter by tags

The new two command line parameters filter the bugs:
- by selecting only the bug which contains at least one tag from the set;
- by excluding the bugs which contains at least one tag from the set.
The two options are mutually exclusive.

Story: 2000876
Task: 6684

Change-Id: I8e2043b4832efda4fac44e65dd56d37e1af393e3

doc/source/migration.rst

@@ -89,6 +89,16 @@ Test Migration
    `$PROJECT_IN_STORYBOARD` should be replaced the name of the project
    you are importing into in StoryBoard, for example `openstack/monasca`.
 
+   Two parameters of the `storyboard-migrate` command
+   allows for filtering by the tags associated to the bug.
+   Both parameters accept a comma-separated lists of tags
+   and they are mutually exclusive.
+
+   --only-tags=tags      select only the bugs which have all
+                         the specified tag(s)
+   --exclude-tags=tags   exclude the bugs which have any
+                         of the specified tag(s)
+
    Then you must wait for some time to pass whilst the project is
    migrated. You can watch the output if you like. Sometimes it will
    crash with a traceback saying the database object already exists.

storyboard/migrate/cli.py

@@ -12,6 +12,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from __future__ import print_function
+import sys
+
 from oslo_config import cfg
 from oslo_log import log
 
@@ -30,7 +33,13 @@ IMPORT_OPTS = [
                help="The origin system from which to import."),
     cfg.IntOpt("auto-increment",
                default=None,
-               help="Optionally set the auto-increment on the stories table.")
+               help="Optionally set the auto-increment on the stories table."),
+    cfg.ListOpt("only-tags",
+                default=[],
+                help="Include only the bugs with specified tags."),
+    cfg.ListOpt("exclude-tags",
+                default=[],
+                help="Exclude the bugs with the specified tags.")
 ]
 
 CONF = cfg.CONF
@@ -46,6 +55,12 @@ def main():
     log.setup(CONF, 'storyboard')
     CONF(project='storyboard')
 
+    # only_tags and exclude_tags are mutually exclusive
+    if CONF.only_tags and CONF.exclude_tags:
+        print('ERROR: only-tags and exclude-tags are mutually exclusive',
+              file=sys.stderr)
+        exit(1)
+
     # If the user requested an autoincrement value, set that before we start
     # importing things. Note that mysql will automatically set the
     # autoincrement to the next-available id equal to or larger than the
@@ -58,7 +73,8 @@ def main():
                         % (auto_increment,))
 
     if CONF.origin is 'launchpad':
-        loader = LaunchpadLoader(CONF.from_project, CONF.to_project)
+        loader = LaunchpadLoader(CONF.from_project, CONF.to_project,
+                                 set(CONF.only_tags), set(CONF.exclude_tags))
         loader.run()
     else:
         print('Unsupported import origin: %s' % CONF.origin)

storyboard/migrate/launchpad/loader.py

@@ -17,16 +17,40 @@ from storyboard.migrate.launchpad.writer import LaunchpadWriter
 
 
 class LaunchpadLoader(object):
-    def __init__(self, from_project, to_project):
+    def __init__(self, from_project, to_project, only_tags=None,
+                 excluded_tags=None):
         """Create a new loader instance from launchpad.org
         """
         self.writer = LaunchpadWriter(to_project)
         self.reader = LaunchpadReader(from_project)
+        self.only_tags = only_tags
+        self.excluded_tags = excluded_tags
+
+    def bug_matches_requested_tags(self, tags):
+        """Check whether the set of tag matches the requirement:
+           - the tag is in the set of the requested tags
+             if the inclusion list is specified;
+           - the tag is not in the set of the excluded tags
+             if the inclusion list is specified.
+        """
+        if self.only_tags:
+            return (tags.intersection(self.only_tags) == self.only_tags)
+        if self.excluded_tags:
+            return not tags.intersection(self.excluded_tags)
+        return True
 
     def run(self):
         for lp_bug in self.reader:
             bug = lp_bug.bug
 
+            tags_set = set()
+            if hasattr(bug, 'tags') and bug.tags:
+                tags_set = set(bug.tags)
+            if not self.bug_matches_requested_tags(tags_set):
+                print("WARNING: Skipping bug %s due to tag rules" %
+                      (bug.self_link))
+                continue
+
             # Preload the tags.
             tags = self.writer.write_tags(bug)