Re-queue topic for some consumers on link edit

After editing a topic's link, we want to re-process it through the
scrapers, setting the domain in its metadata, etc.

tildes/alembic/versions/4ebc3ca32b48_send_rabbitmq_message_on_link_edit.py

@@ -0,0 +1,32 @@
+"""Send rabbitmq message on link edit
+
+Revision ID: 4ebc3ca32b48
+Revises: 24014adda7c3
+Create Date: 2019-03-15 00:59:57.713065
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "4ebc3ca32b48"
+down_revision = "24014adda7c3"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.execute(
+        """
+        CREATE TRIGGER send_rabbitmq_message_for_topic_link_edit
+            AFTER UPDATE ON topics
+            FOR EACH ROW
+            WHEN (OLD.link IS DISTINCT FROM NEW.link)
+            EXECUTE PROCEDURE send_rabbitmq_message_for_topic('link_edited');
+    """
+    )
+
+
+def downgrade():
+    op.execute("DROP TRIGGER send_rabbitmq_message_for_topic_link_edit ON topics")

tildes/consumers/topic_embedly_extractor.py

@@ -93,5 +93,5 @@ if __name__ == "__main__":
     TopicEmbedlyExtractor(
         embedly_api_key,
         queue_name="topic_embedly_extractor.q",
-        routing_keys=["topic.created"],
+        routing_keys=["topic.created", "topic.link_edited"],
     ).consume_queue()

tildes/consumers/topic_metadata_generator.py

@@ -77,5 +77,5 @@ class TopicMetadataGenerator(PgsqlQueueConsumer):
 if __name__ == "__main__":
     TopicMetadataGenerator(
         queue_name="topic_metadata_generator.q",
-        routing_keys=["topic.created", "topic.edited"],
+        routing_keys=["topic.created", "topic.edited", "topic.link_edited"],
     ).consume_queue()

tildes/consumers/topic_youtube_scraper.py

@@ -96,5 +96,5 @@ if __name__ == "__main__":
     TopicYoutubeScraper(
         youtube_api_key,
         queue_name="topic_youtube_scraper.q",
-        routing_keys=["topic.created"],
+        routing_keys=["topic.created", "topic.link_edited"],
     ).consume_queue()

tildes/sql/init/triggers/topics/rabbitmq.sql

@@ -32,3 +32,10 @@ CREATE TRIGGER send_rabbitmq_message_for_topic_edit
     FOR EACH ROW
     WHEN (OLD.markdown IS DISTINCT FROM NEW.markdown)
     EXECUTE PROCEDURE send_rabbitmq_message_for_topic('edited');
+
+
+CREATE TRIGGER send_rabbitmq_message_for_topic_link_edit
+    AFTER UPDATE ON topics
+    FOR EACH ROW
+    WHEN (OLD.link IS DISTINCT FROM NEW.link)
+    EXECUTE PROCEDURE send_rabbitmq_message_for_topic('link_edited');