Implement message classes for abstract messaging

rida/messaging.py

@@ -20,9 +20,131 @@
 # SOFTWARE.
 #
 # Written by Ralph Bean <rbean@redhat.com>
+#            Matt Prahl <mprahl@redhat.com>
 
 """Generic messaging functions."""
 
+import re
+from rida import logger
+
+
+class BaseMessage(object):
+    def __init__(self, msg_id):
+        """
+        A base class to abstract messages from different backends
+        :param msg_id: the id of the msg (e.g. 2016-SomeGUID)
+        """
+        self.msg_id = msg_id
+
+    @staticmethod
+    def from_fedmsg(topic, msg):
+        """
+        Takes a fedmsg topic and message and converts it to a message object
+        :param topic: the topic of the fedmsg message
+        :param msg: the message contents from the fedmsg message
+        :return: an object of BaseMessage descent if the message is a type
+        that the app looks for, otherwise None is returned
+        """
+        regex_pattern = re.compile(
+            (r'(?P<category>buildsys|rida)(?:\.)'
+             r'(?P<object>build|repo|module)(?:(?:\.)'
+             r'(?P<subobject>state))?(?:\.)(?P<event>change|done)$'))
+        regex_results = re.search(regex_pattern, topic)
+
+        if regex_results:
+            category = regex_results.group('category')
+            object = regex_results.group('object')
+            subobject = regex_results.group('subobject')
+            event = regex_results.group('event')
+
+            msg_id = msg.get('msg_id')
+            msg_inner_msg = msg.get('msg')
+
+            # If there isn't a msg dict in msg then this message can be skipped
+            if not msg_inner_msg:
+                logger.debug(('Skipping message without any content with the '
+                             'topic "{0}"').format(topic))
+                return None
+
+            msg_obj = None
+
+            if category == 'buildsys' and object == 'build' and \
+                    subobject == 'state' and event == 'change':
+                build_id = msg_inner_msg.get('build_id')
+                build_new_state = msg_inner_msg.get('new')
+                build_name = msg_inner_msg.get('name')
+                build_version = msg_inner_msg.get('version')
+                build_release = msg_inner_msg.get('release')
+
+                msg_obj = KojiBuildChange(
+                    msg_id, build_id, build_new_state, build_name,
+                    build_version, build_release)
+
+            elif category == 'buildsys' and object == 'repo' and \
+                    subobject is None and event == 'done':
+                repo_tag = msg_inner_msg.get('tag')
+                msg_obj = KojiRepoChange(msg_id, repo_tag)
+
+            elif category == 'rida' and object == 'module' and \
+                    subobject == 'state' and event == 'change':
+                msg_obj = RidaModule(
+                    msg_id, msg_inner_msg.get('id'), msg_inner_msg.get('state'))
+
+            # If the message matched the regex and is important to the app,
+            # it will be returned
+            if msg_obj:
+                return msg_obj
+
+        logger.debug('Skipping unrecognized message with the topic "{0}"'
+                     .format(topic))
+        return None
+
+
+class KojiBuildChange(BaseMessage):
+    """ A class that inherits from BaseMessage to provide a message
+    object for a build's info (in fedmsg this replaces the msg dictionary)
+    :param msg_id: the id of the msg (e.g. 2016-SomeGUID)
+    :param build_id: the id of the build (e.g. 264382)
+    :param build_new_state: the new build state, this is currently a Koji
+    integer
+    :param build_name: the name of what is being built
+    (e.g. golang-googlecode-tools)
+    :param build_version: the version of the build (e.g. 6.06.06)
+    :param build_release: the release of the build (e.g. 4.fc25)
+    """
+    def __init__(self, msg_id, build_id, build_new_state, build_name,
+                 build_version, build_release):
+        super(KojiBuildChange, self).__init__(msg_id)
+        self.build_id = build_id
+        self.build_new_state = build_new_state
+        self.build_name = build_name
+        self.build_version = build_version
+        self.build_release = build_release
+
+
+class KojiRepoChange(BaseMessage):
+    """ A class that inherits from BaseMessage to provide a message
+    object for a repo's info (in fedmsg this replaces the msg dictionary)
+    :param msg_id: the id of the msg (e.g. 2016-SomeGUID)
+    :param repo_tag: the repo's tag (e.g. SHADOWBUILD-f25-build)
+    """
+    def __init__(self, msg_id, repo_tag):
+        super(KojiRepoChange, self).__init__(msg_id)
+        self.repo_tag = repo_tag
+
+
+class RidaModule(BaseMessage):
+    """ A class that inherits from BaseMessage to provide a message
+    object for a module event generated by rida
+    :param msg_id: the id of the msg (e.g. 2016-SomeGUID)
+    :param module_build_id: the id of the module build
+    :param module_build_state: the state of the module build
+    """
+    def __init__(self, msg_id, module_build_id, module_build_state):
+        super(RidaModule, self).__init__(msg_id)
+        self.module_build_id = module_build_id
+        self.module_build_state = module_build_state
+
 
 def publish(topic, msg, backend, modname='rida'):
     """ Publish a single message to a given backend, and return. """