[couchbase-server] Get dates from docs.couchbase.com

Couchbase server was using the dockerhub auto method, which is not reliable.
This new method is not perfect, but at least the dates are acceptable.

src/couchbase-server.py

@@ -0,0 +1,57 @@
+import re
+from bs4 import BeautifulSoup
+from common import endoflife
+from datetime import datetime
+
+"""Fetch versions with their dates from docs.couchbase.com.
+
+Versions are fetched from the release notes of each minor version. Date is not
+accurate (only month and year are provided) but it's already better than the
+previous implementation which use dates of the images on Docker Hub. Because
+of that lack of precision, all dates are set to the 15th of the month.
+
+Notes:
+- documentation for oldest versions is not available anymore on
+  docs.couchbase.com, so this script is using the Wayback Machine to fetch them.
+- dates are not available for some versions, those had to be set manually.
+"""
+
+PRODUCT = "couchbase-server"
+REGEX = r"^Release (?P<version>\d+\.\d+(\.\d+)?) \((?P<date>.+)\)$"
+URLS = [
+    "https://web.archive.org/web/20230519160357/https://docs.couchbase.com/server/",
+    "https://docs.couchbase.com/server",
+]
+FIXED_VERSIONS = {
+    "6.0.0": "2018-10-31",  # https://www.couchbase.com/blog/announcing-couchbase-6-0/
+    "6.0.1": "2019-02-15",  # https://web.archive.org/web/20190307191211/https://docs.couchbase.com/server/6.0/release-notes/relnotes.html
+    "7.2.0": "2023-06-01",  # https://www.couchbase.com/blog/couchbase-capella-spring-release-72/
+}
+
+print(f"::group::{PRODUCT}")
+versions = {}
+
+for base_url in URLS:
+    response = endoflife.fetch_url(f"{base_url}/current/install/install-intro.html")
+    soup = BeautifulSoup(response, features="html5lib")
+    for option in soup.find(class_="version_list").find_all("option"):
+        minor = option.attrs["value"]
+        versions[minor + '.0'] = 'N/A'  # there is no date available for x.y.0
+
+        response = endoflife.fetch_url(f"{base_url}/{minor}/release-notes/relnotes.html")
+        soup = BeautifulSoup(response, features="html5lib")
+        for title in soup.find_all("h2"):
+            versionAndDate = title.get_text().strip()
+            m = re.match(REGEX, versionAndDate)
+            if m:
+                version = f"{m['version']}.0" if len(m['version'].split('.')) == 2 else m['version']
+                date = datetime.strptime(m['date'], "%B %Y").strftime("%Y-%m-15")
+                versions[version] = date
+                print(f"{version}: {date}")
+
+versions = versions | FIXED_VERSIONS
+endoflife.write_releases(PRODUCT, dict(
+    # sort by date then version (desc)
+    sorted(versions.items(), key=lambda x: (x[1], x[0]), reverse=True)
+))
+print("::endgroup::")