fix: disable client connections during upgrade

Author: soedirgo

ansible/files/admin_api_scripts/pg_upgrade_scripts/common.sh

@@ -88,6 +88,10 @@ CI_start_postgres() {
 
 swap_postgres_and_supabase_admin() {
     run_sql <<'EOSQL'
+alter database postgres connection limit 0;
+select pg_terminate_backend(pid) from pg_stat_activity where backend_type = 'client backend' and pid != pg_backend_pid();
+EOSQL
+    run_sql <<'EOSQL'
 set statement_timeout = '300s';
 begin;
 create role supabase_tmp superuser;
@@ -509,6 +513,8 @@ begin
 end
 $$;
 
+alter database postgres connection limit -1;
+
 set session authorization supabase_admin;
 drop role supabase_tmp;
 commit;

ansible/files/admin_api_scripts/pg_upgrade_scripts/initiate.sh

@@ -125,6 +125,9 @@ cleanup() {
     echo "Removing SUPERUSER grant from postgres"
     run_sql -c "ALTER USER postgres WITH NOSUPERUSER;"
 
+    echo "Resetting postgres database connection limit"
+    run_sql -c "ALTER DATABASE postgres CONNECTION LIMIT -1;"
+
     if [ -z "$IS_CI" ] && [ -z "$IS_LOCAL_UPGRADE" ]; then
         echo "Unmounting data disk from ${MOUNT_POINT}"
         umount $MOUNT_POINT