From 0dce03a5f855eed4cc6b004c97cf56c5a25013bf Mon Sep 17 00:00:00 2001
From: Ian Barwick <ian@2ndquadrant.com>
Date: Wed, 16 Oct 2019 13:15:04 +0900
Subject: [PATCH] standby clone: don't query upstream's data directory

In early repmgr versions, this used to be a requirement for cloning
via rsync, and/or as a fallback location if the user didn't supply
a data directory to clone into. However as rsync cloning has been
deprecated, and the data directory must be specified in repmgr.conf,
this is no longer required, and removing it simplifies user privilege
requirements.

Note that it is still possible to explicitly provide a target data
directory with -D/--pgdata, though this is primarily useful for
the niche use case where repmgr is used as a convenience tool to
clone a node which is not intended to become part of a repmgr
cluster.

This is part of the implementation of GitHub #536 for the minimizing
of user privilege requirements.
---
 HISTORY                 |  3 +++
 repmgr-action-standby.c | 33 +++------------------------------
 2 files changed, 6 insertions(+), 30 deletions(-)

diff --git a/HISTORY b/HISTORY
index 6356adbb..846a1886 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,3 +1,6 @@
+5.1     2019-??-??
+        repmgr: don't query upstream's data directory (Ian)
+
 5.0     2019-10-15
         general: add PostgreSQL 12 support (Ian)
         general: parse configuration file using flex (Ian)
diff --git a/repmgr-action-standby.c b/repmgr-action-standby.c
index d2c373d9..a6f90f5b 100644
--- a/repmgr-action-standby.c
+++ b/repmgr-action-standby.c
@@ -72,7 +72,6 @@ static bool local_data_directory_provided = false;
 
 static bool upstream_conninfo_found = false;
 static int	upstream_node_id = UNKNOWN_NODE_ID;
-static char upstream_data_directory[MAXPGPATH] = "";
 
 static t_conninfo_param_list recovery_conninfo = T_CONNINFO_PARAM_LIST_INITIALIZER;
 static char recovery_conninfo_str[MAXLEN] = "";
@@ -4810,9 +4809,6 @@ do_standby_switchover(void)
 static void
 check_source_server()
 {
-	PGconn	   *superuser_conn = NULL;
-	PGconn	   *privileged_conn = NULL;
-
 	char		cluster_size[MAXLEN];
 	char	   *connstr = NULL;
 
@@ -4988,9 +4984,6 @@ check_source_server()
 								PQfinish(source_conn);
 								source_conn = NULL;
 
-								if (superuser_conn != NULL)
-									PQfinish(superuser_conn);
-
 								exit(ERR_BAD_CONFIG);
 							}
 							/* identifiers match - our work here is done */
@@ -5006,26 +4999,6 @@ check_source_server()
 			}
 		}
 	}
-	/* Fetch the source's data directory */
-	get_superuser_connection(&source_conn, &superuser_conn, &privileged_conn);
-
-	if (get_pg_setting(privileged_conn, "data_directory", upstream_data_directory) == false)
-	{
-		log_error(_("unable to retrieve source node's data directory"));
-		log_detail(_("STANDBY CLONE must be run with database superuser permissions"));
-		log_hint(_("provide a database superuser name with -S/--superuser"));
-
-		PQfinish(source_conn);
-		source_conn = NULL;
-
-		if (superuser_conn != NULL)
-			PQfinish(superuser_conn);
-
-		exit(ERR_BAD_CONFIG);
-	}
-
-	if (superuser_conn != NULL)
-		PQfinish(superuser_conn);
 
 	/*
 	 * If no target data directory was explicitly provided, we'll default to
@@ -5033,10 +5006,10 @@ check_source_server()
 	 */
 	if (local_data_directory_provided == false)
 	{
-		strncpy(local_data_directory, upstream_data_directory, MAXPGPATH);
-
-		log_notice(_("setting data directory to: \"%s\""), local_data_directory);
+		log_error(_("no data directory provided"));
 		log_hint(_("use -D/--pgdata to explicitly specify a data directory"));
+		PQfinish(source_conn);
+		exit(ERR_BAD_CONFIG);
 	}
 
 	/*