[discourse] Add auto method (#515)

Closes #505.

src/discourse.py

@@ -0,0 +1,30 @@
+import logging
+import re
+
+from bs4 import BeautifulSoup
+from common import dates, http
+from common.releasedata import ProductData, config_from_argv
+
+"""Fetch versions from a discourse server."""
+
+config = config_from_argv()
+with ProductData(config.product) as product_data:
+    html = BeautifulSoup(http.fetch_javascript_url(config.url))
+
+    for topic in html.select("tr.topic-list-item"):
+        title = topic.select_one("span.link-top-line").get_text(strip=True)
+        versions = config.first_match(title)
+        if not versions:
+            logging.debug("Skipping %s: does not match regex", title)
+            continue
+
+        name = config.render(versions)
+        print(topic)
+        date_str = topic.select_one("td.activity").get("title").strip()
+        date_match = re.search(r"Created:\s*([A-Za-z]+\s+\d{1,2},\s+\d{4}\s+\d{1,2}:\d{2}\s+[ap]m)", date_str)
+        if not date_match:
+            logging.debug("Skipping %s: no created date found", title)
+            continue
+
+        date = dates.parse_datetime(date_match.group(1))
+        product_data.declare_version(name, date)