From f982708b350d8d646cd8f2455dc1f619a638a980 Mon Sep 17 00:00:00 2001
From: Ian Barwick <ian@2ndquadrant.com>
Date: Wed, 20 Jan 2016 07:56:03 +0900
Subject: [PATCH] Add function test_db_connection()

The difference between this and establish_db_connection() is that
it outputs any connection failure as a [NOTICE] rather than an
[ERROR]; it's intended for use in e.g. polling a server to wait
for it to come up/go down, while preventing [ERROR] log lines
which may cause confusion.
---
 dbutils.c | 28 +++++++++++++++++++++++++---
 dbutils.h |  7 ++++++-
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/dbutils.c b/dbutils.c
index 1df56738..0f9b5bff 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -29,8 +29,9 @@
 char repmgr_schema[MAXLEN] = "";
 char repmgr_schema_quoted[MAXLEN] = "";
 
+
 PGconn *
-establish_db_connection(const char *conninfo, const bool exit_on_error)
+_establish_db_connection(const char *conninfo, const bool exit_on_error, const bool log_notice)
 {
 	/* Make a connection to the database */
 	PGconn	   *conn = NULL;
@@ -46,8 +47,16 @@ establish_db_connection(const char *conninfo, const bool exit_on_error)
 	/* Check to see that the backend connection was successfully made */
 	if ((PQstatus(conn) != CONNECTION_OK))
 	{
-		log_err(_("connection to database failed: %s\n"),
-				PQerrorMessage(conn));
+		if (log_notice)
+		{
+			log_notice(_("connection to database failed: %s\n"),
+					PQerrorMessage(conn));
+		}
+		else
+		{
+			log_err(_("connection to database failed: %s\n"),
+					PQerrorMessage(conn));
+		}
 
 		if (exit_on_error)
 		{
@@ -59,6 +68,19 @@ establish_db_connection(const char *conninfo, const bool exit_on_error)
 	return conn;
 }
 
+PGconn *
+establish_db_connection(const char *conninfo, const bool exit_on_error)
+{
+	return _establish_db_connection(conninfo, exit_on_error, false);
+}
+
+PGconn *
+test_db_connection(const char *conninfo, const bool exit_on_error)
+{
+	return _establish_db_connection(conninfo, exit_on_error, true);
+}
+
+
 PGconn *
 establish_db_connection_by_params(const char *keywords[], const char *values[],
 								  const bool exit_on_error)
diff --git a/dbutils.h b/dbutils.h
index 7aa4b653..ddc2906d 100644
--- a/dbutils.h
+++ b/dbutils.h
@@ -78,8 +78,13 @@ typedef struct s_replication_slot
   InvalidXLogRecPtr \
 }
 
+PGconn *_establish_db_connection(const char *conninfo,
+								 const bool exit_on_error,
+								 const bool log_notice);
 PGconn *establish_db_connection(const char *conninfo,
-						const bool exit_on_error);
+								const bool exit_on_error);
+PGconn *test_db_connection(const char *conninfo,
+						   const bool exit_on_error);
 PGconn *establish_db_connection_by_params(const char *keywords[],
 								  const char *values[],
 								  const bool exit_on_error);