Add matrix room cleaning script

scripts/matrix/clean-old-rooms.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -eou pipefail
+
+# Get the list of rooms with no local users
+empty_rooms() {
+    psql -d synapse -c "SELECT room_id FROM room_stats_current WHERE local_users_in_room = 0 \
+        ORDER BY current_state_events DESC LIMIT 1;" -t --csv
+}
+
+# Delete a room and purge its history
+delete_room() {
+    details=$(synadm room details $1)
+    name=$(echo $details | jq -r '.name')
+    canonical_alias=$(echo $details | jq -r '.canonical_aliacanonical_alias')
+    topic=$(echo $details | jq -r '.topic')
+    joined_local_members=$(echo $details | jq -r '.joined_local_members')
+    state_events=$(echo $details | jq -r '.state_events')
+    echo "Deleting room $1 (name: $name, canonical alias: $canonical_alias, topic: $topic)[$joined_local_members]"
+    echo "This will remove $state_events state events"
+    if [[ $joined_local_members == "0" ]];
+    then
+        time synadm --yes room delete $1
+    else
+        echo "Room still had active members!!! $1"
+    fi
+    echo ""
+}
+
+log_file="empty-removal-$(date -Iminutes).log"
+touch $log_file
+for room in $(empty_rooms); do
+    delete_room $room | tee -a $log_file
+done