[rds] Adds automation (#86)

This is a Python rewrite of the code at #83.

Co-authored-by: Nemo <commits@captnemo.in>
Co-authored-by: Marc Wrobel <marc.wrobel@gmail.com>

src/rds.py

@@ -0,0 +1,45 @@
+import re
+import urllib.request
+from bs4 import BeautifulSoup
+from datetime import datetime
+import json
+
+dbs = {
+    "mysql": "https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/MySQL.Concepts.VersionMgmt.html",
+    "postgresql": "https://docs.aws.amazon.com/AmazonRDS/latest/PostgreSQLReleaseNotes/postgresql-release-calendar.html",
+}
+
+
+def parse_date(d):
+    return datetime.strptime(d, "%d %B %Y").strftime("%Y-%m-%d")
+
+
+for db, url in dbs.items():
+    print(f"::group::{db}")
+    releases = {}
+
+    with urllib.request.urlopen(url, data=None, timeout=5) as contents:
+        html = contents.read().decode("utf-8")
+        soup = BeautifulSoup(html, features="html5lib")
+
+        for table in soup.find_all("table"):
+            for row in table.find_all("tr"):
+                columns = row.find_all("td")
+
+                # Must match both the 'Supported XXX minor versions' and
+                # 'Supported XXX major versions' to have correct release dates
+                if len(columns) > 3:
+                    r = r"(?P<v>\d+(?:\.\d+)*)" # https://regex101.com/r/BY1vwV/1
+                    m = re.search(r, columns[0].text.strip(), flags=re.IGNORECASE)
+                    if m:
+                        version = m.group("v")
+                        date = parse_date(columns[2].text.strip())
+                        print(f"{version} : {date}")
+                        releases[version] = date
+
+    print("::endgroup::")
+    with open(f"releases/amazon-rds-{db.lower()}.json", "w") as f:
+        json.dump(dict(
+            # sort by date then version (desc)
+            sorted(releases.items(), key=lambda x: (x[1], x[0]), reverse=True)
+        ), f, indent=2)