[mailman3] Add script for generating fulltext index for mailing lists

The index generated by the hyperkitty-hourly script generated unusually big
index (around 1TB).

This script should help with generating the search index from scratch, after
that we can leave it to hyperkitty-hourly job again.

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

roles/mailman3/files/generate_search_index.py

@@ -0,0 +1,63 @@
+"""This script is used to generate fulltext search index from scratch."""
+#!/usr/bin/env python
+import argparse
+import os
+import sys
+from subprocess import call
+
+import django
+from django.db import connection
+
+# Read the database information from mailman config
+sys.path.insert(0, '/etc/mailman3')
+if not os.getenv("DJANGO_SETTINGS_MODULE"):
+    os.environ["DJANGO_SETTINGS_MODULE"] = "settings"
+
+
+# User to use for running mailman-web command
+MAILMAN_USER = "mailman"
+
+
+def get_mailinglists() -> list:
+    """Get list of all the archived mailing lists."""
+    mailinglists = []
+    with connection.cursor() as cursor:
+        print("Retriving list of archived mailinglists...")
+        cursor.execute("SELECT name FROM hyperkitty_mailinglist")
+
+        # This is needed to convert the results from list of tuple to
+        # plain list
+        for mailinglist in cursor:
+            mailinglists.append(mailinglist[0])
+        print("List retrieved: {0} entries".format(len(mailinglists)))
+
+        return mailinglists
+
+
+def generate_index(mailinglists: list) -> None:
+    """Generate indexes for the lists one by one."""
+    for mailinglist in mailinglists:
+        print("Generating index for {0}".format(mailinglist))
+        call(["sudo", "-u", MAILMAN_USER, "mailman-web", "update_index_one_list", mailinglist])
+        print("Finished generating index for {0}".format(mailinglist))
+
+
+if __name__ == "__main__":
+    django.setup()
+    parser = argparse.ArgumentParser(description=(
+        "This script is used to generate fulltext search index from scratch. "
+        "It will obtain the list of mailinglist, sort it alphabetically and "
+        "generate index for them one by one."
+        )
+    )
+    parser.add_argument('--start-from', dest="start_from", help="When generating index start from this mailing list.")
+    args = parser.parse_args()
+    mailinglists = get_mailinglists()
+    mailinglists.sort()
+    if args.start_from:
+        # Check if the list exists in list
+        if args.start_from in mailinglists:
+            index = mailinglists.index(args.start_from)
+            mailinglists = mailinglists[index:]
+
+    generate_index(mailinglists)