Add options -U (username) and -d (database) in pgxc_monitor

This allows to monitor a node with a simple command using a wanted
user name and/or database for a Coordinator and a Datanode.
In case a password is necessary, it is necessary to provide it
through .pgpass.

Feature design and patch by Nikhil Sontakke.
I just reviewed and corrected a couple of things.

2 files changed, 85 insertions, 22 deletions

diff --git a/contrib/pgxc_monitor/pgxc_monitor.c b/contrib/pgxc_monitor/pgxc_monitor.c
index 5db91b7eaa..e1aafae5f2 100644
--- a/contrib/pgxc_monitor/pgxc_monitor.c
+++ b/contrib/pgxc_monitor/pgxc_monitor.c
@@ -7,7 +7,7 @@
  *
  * Command syntax:
  *
- * pgxc_monitor -Z nodetype -p port -h host
+ * pgxc_monitor [ options ]
  *
  * Options are:
  * -Z nodetype		What node type to monitor, gtm or node.
@@ -18,6 +18,8 @@
  * -n nodename      Specifies pgxc_monitor node name. Default is "pgxc_monitor"
  * -q				Run in quiet mode. Default is quiet mode.
  * -v				Run in verbose mode.
+ * -d database		Database name to connect to.
+ * -U username		Connect as specified database user.
  * --help			Prints the help message and exits with 0.
  *
  * When monitoring Coordinator or Datanode, -p and -h options can be
@@ -32,6 +34,9 @@
  * When testing Coordinator/Datanode, you must setup .pgpass file if you
  * need to supply password, as well as non-default database name and username.
  *
+ * The username and database name can be specified via command line options
+ * too. If password is needed, it must be supplied via .pgpass file though.
+ *
  * If invalid parameters are given, error message will be printed even if
  * -q is specified.
  *
@@ -59,7 +64,7 @@ static char 	*progname;
 
 static void usage(void);
 static int do_gtm_ping(char *host, char *node, nodetype_t nodetype, char *nodename, bool verbose);
-static int do_node_ping(char *host, char *node, bool verbose);
+static int do_node_ping(char *host, char *node, char *username, char *database, bool verbose);
 
 int
 main(int ac, char *av[])
@@ -70,6 +75,8 @@ main(int ac, char *av[])
 	char	   *host = NULL;
 	char	   *nodename = NULL;
 	bool		verbose = false;
+	char	   *username = NULL;
+	char	   *database = NULL;
 
 	progname = strdup(av[0]);
 
@@ -84,7 +91,7 @@ main(int ac, char *av[])
 	}
 
 	/* Scan options */
-	while ((opt = getopt(ac, av, "Z:h:n:p:qv")) != -1)
+	while ((opt = getopt(ac, av, "Z:U:d:h:n:p:qv")) != -1)
 	{
 		switch(opt)
 		{
@@ -117,6 +124,12 @@ main(int ac, char *av[])
 			case 'v':
 				verbose = true;
 				break;
+			case 'U':
+				username = strdup(optarg);
+				break;
+			case 'd':
+				database = strdup(optarg);
+				break;
 			default:
 				fprintf(stderr, "%s: unknow option %c.\n", progname, opt);
 				exit(3);
@@ -136,7 +149,7 @@ main(int ac, char *av[])
 		case GTM:
 			exit(do_gtm_ping(host, port, nodetype, nodename, verbose));
 		case NODE:
-			exit(do_node_ping(host, port, verbose));
+			exit(do_node_ping(host, port, username, database, verbose));
 		case NONE:
 		default:
 			break;
@@ -150,7 +163,8 @@ main(int ac, char *av[])
 /*
  * Ping a given GTM or GTM-proxy
  */
-static int do_gtm_ping(char *host, char* port, nodetype_t nodetype, char *nodename, bool verbose)
+static int
+do_gtm_ping(char *host, char* port, nodetype_t nodetype, char *nodename, bool verbose)
 {
 	char connect_str[256];
 	GTM_Conn *conn;
@@ -170,7 +184,7 @@ static int do_gtm_ping(char *host, char* port, nodetype_t nodetype, char *nodena
 	if ((conn = PQconnectGTM(connect_str)) == NULL)
 	{
 		if (verbose)
-			fprintf(stderr, "%s: Could not connect to %s\n", progname, nodetype == GTM ? "GTM" : "GTM_Proxy");
+			fprintf(stderr, "%s: Could not connect to %s\n", progname, "GTM");
 		exit(1);
 	}
 	GTMPQfinish(conn);
@@ -182,12 +196,13 @@ static int do_gtm_ping(char *host, char* port, nodetype_t nodetype, char *nodena
 /*
  * Ping a given node
  */
-static int do_node_ping(char *host, char *port, bool verbose)
+static int
+do_node_ping(char *host, char *port, char *username, char *database, bool verbose)
 {
 	int rc;
 	int exitStatus;
-	char command_line[512];
-	char *quiet_out = "> /dev/null 2> /dev/null";
+	char command_line[1024];
+	char *quiet_out = " > /dev/null 2> /dev/null";
 	char *verbose_out = "";
 	char *out = verbose ? verbose_out : quiet_out;
 
@@ -195,14 +210,34 @@ static int do_node_ping(char *host, char *port, bool verbose)
 	sprintf(command_line, "psql -w -q -c \"select 1 a\"");
 
 	/* Then add options if necessary */
+	if (username)
+	{
+		strcat(command_line, " -U ");
+		strcat(command_line, username);
+	}
+
+	/* Add database name, default is "postgres" */
+	if (database)
+	{
+		strcat(command_line, " -d ");
+		strcat(command_line, database);
+	}
+	else
+		strcat(command_line, " -d postgres ");
+
 	if (host)
-		sprintf(command_line, "%s -h %s", command_line, host);
+	{
+		strcat(command_line, " -h ");
+		strcat(command_line, host);
+	}
+
 	if (port)
-		sprintf(command_line, "%s -p %s", command_line, port);
+	{
+		strcat(command_line, " -p ");
+		strcat(command_line, port);
+	}
 
-	/* Add database name, here default database, postgres, is used */
-	sprintf(command_line, "%s postgres", command_line);
-	sprintf(command_line, "%s %s", command_line, out);
+	strcat(command_line, out);
 
 	/* Launch the command and output result if necessary */
 	rc = system(command_line);
@@ -221,18 +256,22 @@ static int do_node_ping(char *host, char *port, bool verbose)
 /*
  * Show help information
  */
-static void usage(void)
+static void
+usage(void)
 {
 	printf("pgxc_monitor -Z nodetype -p port -h host\n\n");
 	printf("Options are:\n");
-	printf("    -Z nodetype	    What node type to monitor, gtm, gtm_proxy,\n");
-	printf("                    coordinator, or datanode.\n");
+	printf("    -Z nodetype	    What node type to monitor, GTM, GTM-Proxy,\n");
+	printf("                    Coordinator, or Datanode.\n");
+	printf("                    Use \"gtm\" for GTM and GTM-proxy, \"node\" for Coordinator and Datanode.\n");
 	printf("    -h host         Host name or IP address of the monitored node.\n");
-	printf("                    Mandatory for -Z gtm or -Z gtm_proxy\n");
+	printf("                    Mandatory for -Z gtm\n");
 	printf("    -n nodename     Nodename of this pgxc_monitor.\n");
-	printf("                    Only for -Z gtm or -Z gtm_proxy. Default is pgxc_monitor\n");
+	printf("                    Only for -Z gtm. Default is pgxc_monitor\n");
 	printf("                    This identifies what is the name of component connecting to GTM.\n");
-	printf("    -p port         Port number of the monitored node. Mandatory for -Z gtm or -Z gtm_proxy\n");
+	printf("    -p port         Port number of the monitored node. Mandatory for -Z gtm\n");
+	printf("    -d database     Database name to connect to. Default is \"postgres\".  \n");
+	printf("    -U username     Connect as specified database user. \n");
 	printf("    -q              Quiet mode.\n");
 	printf("    -v              Verbose mode.\n");
 	printf("    --help          Prints the help message and exits with 0.\n");
diff --git a/doc-xc/src/sgml/pgxcmonitor.sgmlin b/doc-xc/src/sgml/pgxcmonitor.sgmlin
index eac36d4d8e..f798f2c15b 100644
--- a/doc-xc/src/sgml/pgxcmonitor.sgmlin
+++ b/doc-xc/src/sgml/pgxcmonitor.sgmlin
@@ -47,8 +47,9 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
       <term><option>-Z <replaceable class="parameter">nodetype</replaceable></option></term>
       <listitem>
       <para>
-       Type of node type to test. Specify gtm as <replaceable>nodetype</replaceable> for gtm and gtm_proxy.
-       Specify node as <replaceable>nodeopt</replaceable> for a Coordinator or a Datanode.
+       Type of node type to test. Specify <literal>gtm</> as <replaceable>nodetype</replaceable>
+       for gtm and gtm_proxy and <literal>node</> as <replaceable>nodetype</replaceable> for a
+       Coordinator or a Datanode.
       </para>
       </listitem>
     </varlistentry>
@@ -82,6 +83,24 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
     </varlistentry>
 
     <varlistentry>
+      <term><option>-U <replaceable class="parameter">username</replaceable></></term>
+      <listitem>
+      <para>
+       Specifies the database username to connect as.
+      </para>
+      </listitem>
+    </varlistentry>
+
+    <varlistentry>
+      <term><option>-d <replaceable class="parameter">database</replaceable></></term>
+      <listitem>
+      <para>
+       Specifies the database name to connect to. Default is "postgres".
+      </para>
+      </listitem>
+    </varlistentry>
+
+    <varlistentry>
       <term><option>-q</></term>
       <listitem>
       <para>
@@ -133,6 +152,11 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
    Also, because this uses psql command, psql must be in your PATH.
   </para>
   <para>
+   The username and database name can be specified via command line
+   options too. If password is needed, it must be supplied via
+   <option>.pgpass</option> file though.
+  </para>
+  <para>
    If invalid parameters are given, 
    error message will be printed even if <option>-q</option> is specified.
   </para>