Fix monitor postgres not starting up the first time (#752)

Author: JelteF

src/bin/pg_autoctl/fsm_transition.c

@@ -1463,10 +1463,19 @@ fsm_init_from_standby(Keeper *keeper)
 /*
  * fsm_drop_node is called to finish dropping a node on the client side.
  *
- * Nothing to do here, really.
+ * This stops postgres and updates the postgres state file to say that postgres
+ * should be stopped. It also cleans up any existing init file. Not doing these
+ * two things can confuse a possible future re-init of the node.
  */
 bool
 fsm_drop_node(Keeper *keeper)
 {
-	return true;
+	KeeperConfig *config = &(keeper->config);
+	if (!fsm_stop_postgres(keeper))
+	{
+		/* errors have already been logged */
+		return false;
+	}
+
+	return unlink_file(config->pathnames.init);
 }

src/bin/pg_autoctl/keeper.c

@@ -1673,6 +1673,22 @@ keeper_register_and_init(Keeper *keeper, NodeState initialState)
 		goto rollback;
 	}
 
+	/*
+	 * If we dropped a primary using --force, it's possible that the postgres
+	 * state file still says that postgres should be running. In that case
+	 * postgres would probably be running now. The problem is that our
+	 * fsm_init_primary transation errors out when a postgres is running during
+	 * initialization. So if we were dropped and this is the first time
+	 * create is run after that, then we first stop postgres and record this
+	 * in our postgres state file.
+	 */
+	if (keeper->state.current_role == DROPPED_STATE &&
+		!file_exists(keeper->config.pathnames.init))
+	{
+		log_info("Making sure postgres was stopped, when it was previously dropped");
+		ensure_postgres_service_is_stopped(&keeper->postgres);
+	}
+
 	/*
 	 * Leave a track record that we're ok to initialize in PGDATA, so that in
 	 * case of `pg_autoctl create` being interrupted, we may resume operations

src/bin/pg_autoctl/service_postgres_ctl.c

@@ -188,16 +188,6 @@ service_postgres_ctl_loop(LocalPostgresServer *postgres)
 	/* make sure to initialize the expected Postgres status to unknown */
 	pgStatus->pgExpectedStatus = PG_EXPECTED_STATUS_UNKNOWN;
 
-	if (pg_setup_pgdata_exists(pgSetup))
-	{
-		if (!local_postgres_set_status_path(postgres, true))
-		{
-			log_error("Failed to clean-up postgres state file pathname, "
-					  "see above for details.");
-			exit(EXIT_CODE_BAD_STATE);
-		}
-	}
-
 	for (;;)
 	{
 		int status;