Initial code for standby clone

Makefile.in

@@ -26,7 +26,7 @@ include Makefile.global
 
 $(info Building against PostgreSQL $(MAJORVERSION))
 
-REPMGR_CLIENT_OBJS = repmgr-client.o repmgr-action-master.o repmgr-action-cluster.o \
+REPMGR_CLIENT_OBJS = repmgr-client.o repmgr-action-master.o repmgr-action-standby.o repmgr-action-cluster.o \
   config.o log.o strutil.o dbutils.o
 REPMGRD_OBJS = repmgrd.o
 

repmgr-action-standby.c

@@ -0,0 +1,75 @@
+/*
+ * repmgr-action-standby.c
+ *
+ * Implements standby actions for the repmgr command line utility
+ *
+ * Copyright (c) 2ndQuadrant, 2010-2017
+ */
+
+#include "repmgr.h"
+
+#include "repmgr-client-global.h"
+#include "repmgr-action-standby.h"
+
+
+
+void
+do_standby_clone(void)
+{
+	PGconn	   *primary_conn = NULL;
+	PGconn	   *source_conn = NULL;
+	PGresult   *res;
+
+	int			server_version_num = -1;
+	char		cluster_size[MAXLEN];
+
+	/*
+	 * conninfo params for the actual upstream node (which might be different
+	 * to the node we're cloning from) to write to recovery.conf
+	 */
+	t_conninfo_param_list recovery_conninfo;
+	char		recovery_conninfo_str[MAXLEN];
+	bool		upstream_record_found = false;
+	int		    upstream_node_id = UNKNOWN_NODE_ID;
+
+
+	enum {
+		barman,
+		rsync,
+		pg_basebackup
+	}			mode;
+
+	/* used by barman mode */
+	char        datadir_list_filename[MAXLEN];
+	char		local_repmgr_tmp_directory[MAXPGPATH];
+
+	puts("standby clone");
+
+
+	/*
+	 * detecting the cloning mode
+	 */
+	if (runtime_options.rsync_only)
+		mode = rsync;
+	else if (strcmp(config_file_options.barman_server, "") != 0 && ! runtime_options.without_barman)
+		mode = barman;
+	else
+		mode = pg_basebackup;
+
+	/*
+	 * In rsync mode, we need to check the SSH connection early
+	 */
+	if (mode == rsync)
+	{
+		int r;
+
+		r = test_ssh_connection(runtime_options.host, runtime_options.remote_user);
+		if (r != 0)
+		{
+			log_error(_("remote host %s is not reachable via SSH"),
+					  runtime_options.host);
+			exit(ERR_BAD_SSH);
+		}
+	}
+
+}

repmgr-action-standby.h

@@ -0,0 +1,12 @@
+/*
+ * repmgr-action-standby.h
+ * Copyright (c) 2ndQuadrant, 2010-2017
+ */
+
+#ifndef _REPMGR_ACTION_STANDBY_H_
+#define _REPMGR_ACTION_STANDBY_H_
+
+extern void do_standby_clone(void);
+
+
+#endif

repmgr-client-global.h

@@ -28,6 +28,8 @@ typedef struct
 	bool		verbose;
 
 	/* connection options */
+	char		host[MAXLEN];
+	char		remote_user[MAXLEN];
 	char		superuser[MAXLEN];
 
 	/* node options */
@@ -35,6 +37,10 @@ typedef struct
 	char		node_name[MAXLEN];
 	char		data_dir[MAXPGPATH];
 
+	/* standby clone options */
+	bool		rsync_only;
+	bool		without_barman;
+
 	/* event options */
 	char		event[MAXLEN];
 	int			limit;
@@ -42,12 +48,32 @@ typedef struct
 
 }	t_runtime_options;
 
+#define T_RUNTIME_OPTIONS_INITIALIZER { \
+		/* configuration metadata */ \
+		false, false, false, false,	\
+		/* general configuration options */	\
+		"", false, "", \
+		/* logging options */ \
+		"", false, false, false, \
+		/* connection options */ \
+		"", "", "",			 \
+		/* node options */ \
+		UNKNOWN_NODE_ID, "", "", \
+		/* standby clone options */ \
+		false, false, 		\
+		/* event options */ \
+		"", 20, false}
+
+
+
 /* global configuration structures */
 extern t_runtime_options runtime_options;
 extern t_configuration_options config_file_options;
 
+t_conninfo_param_list source_conninfo;
 
-extern bool	config_file_required;
+
+extern bool	 config_file_required;
 extern char	 pg_bindir[MAXLEN];
 
 extern char	 repmgr_slot_name[MAXLEN];
@@ -58,5 +84,7 @@ extern t_node_info target_node_info;
 
 extern int check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *server_version_string);
 extern bool create_repmgr_extension(PGconn *conn);
+extern int test_ssh_connection(char *host, char *remote_user);
+
 
 #endif

repmgr-client.c

@@ -20,20 +20,30 @@
 #include "repmgr.h"
 #include "repmgr-client.h"
 #include "repmgr-client-global.h"
-#include "repmgr-action-cluster.h"
 #include "repmgr-action-master.h"
+#include "repmgr-action-standby.h"
+#include "repmgr-action-cluster.h"
+
+
+/* globally available variables *
+ * ============================ */
 
 t_runtime_options runtime_options = T_RUNTIME_OPTIONS_INITIALIZER;
 t_configuration_options config_file_options = T_CONFIGURATION_OPTIONS_INITIALIZER;
 
+/* conninfo params for the node we're cloning from */
+t_conninfo_param_list source_conninfo;
 
-
-bool	config_file_required = true;
+bool	 config_file_required = true;
 char	 pg_bindir[MAXLEN] = "";
 
 char	 repmgr_slot_name[MAXLEN] = "";
-char *repmgr_slot_name_ptr = NULL;
+char	*repmgr_slot_name_ptr = NULL;
 
+/*
+ * if --node-id/--node-name provided, place that node's record here
+ * for later use
+ */
 t_node_info target_node_info = T_NODE_INFO_INITIALIZER;
 
 
@@ -115,6 +125,19 @@ main(int argc, char **argv)
 			/* connection options */
 			/* ------------------ */
 
+			/* -h/--host */
+			case 'h':
+				strncpy(runtime_options.host, optarg, MAXLEN);
+				param_set(&source_conninfo, "host", optarg);
+				runtime_options.connection_param_provided = true;
+				runtime_options.host_param_provided = true;
+				break;
+
+			/* -R/--remote_user */
+			case 'R':
+				strncpy(runtime_options.remote_user, optarg, MAXLEN);
+				break;
+
 			/* -S/--superuser */
 			case 'S':
 				strncpy(runtime_options.superuser, optarg, MAXLEN);
@@ -748,12 +771,6 @@ do_help(void)
 
 
 
-static void
-do_standby_clone(void)
-{
-	puts("standby clone");
-}
-
 
 
 
@@ -992,3 +1009,41 @@ check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *
 
 	return server_version_num;
 }
+
+
+int
+test_ssh_connection(char *host, char *remote_user)
+{
+	char		script[MAXLEN];
+	int			r = 1, i;
+
+	/* On some OS, true is located in a different place than in Linux
+	 * we have to try them all until all alternatives are gone or we
+	 * found `true' because the target OS may differ from the source
+	 * OS
+	 */
+	const char *bin_true_paths[] = {
+		"/bin/true",
+		"/usr/bin/true",
+		NULL
+	};
+
+	for (i = 0; bin_true_paths[i] && r != 0; ++i)
+	{
+		if (!remote_user[0])
+			maxlen_snprintf(script, "ssh -o Batchmode=yes %s %s %s 2>/dev/null",
+							config_file_options.ssh_options, host, bin_true_paths[i]);
+		else
+			maxlen_snprintf(script, "ssh -o Batchmode=yes %s %s -l %s %s 2>/dev/null",
+							config_file_options.ssh_options, host, remote_user,
+							bin_true_paths[i]);
+
+		log_verbose(LOG_DEBUG, _("test_ssh_connection(): executing %s"), script);
+		r = system(script);
+	}
+
+	if (r != 0)
+		log_warning(_("unable to connect to remote host '%s' via SSH"), host);
+
+	return r;
+}

repmgr-client.h

@@ -70,9 +70,10 @@ static struct option long_options[] =
 	{"pg_bindir", required_argument, NULL, 'b'},
 
 /* connection options */
+	{"host", required_argument, NULL, 'h'},
+	{"remote-user", required_argument, NULL, 'R'},
 	{"superuser", required_argument, NULL, 'S'},
 
-
 /* node options */
 	{"pgdata", required_argument, NULL, 'D'},
 	/* legacy alias for -D/--pgdata*/
@@ -86,6 +87,10 @@ static struct option long_options[] =
 	{"terse", required_argument, NULL, 't'},
 	{"verbose", no_argument, NULL, 'v'},
 
+/* standby clone options */
+	{"rsync-only", no_argument, NULL, 'r'},
+	{"without-barman", no_argument, NULL, OPT_WITHOUT_BARMAN},
+
 /* event options */
 	{"event", required_argument, NULL, OPT_EVENT },
 	{"limit", required_argument, NULL, OPT_LIMIT },
@@ -93,10 +98,8 @@ static struct option long_options[] =
 
 /* not yet handled */
 	{"dbname", required_argument, NULL, 'd'},
-	{"host", required_argument, NULL, 'h'},
 	{"port", required_argument, NULL, 'p'},
 	{"username", required_argument, NULL, 'U'},
-	{"remote-user", required_argument, NULL, 'R'},
 	{"wal-keep-segments", required_argument, NULL, 'w'},
 	{"keep-history", required_argument, NULL, 'k'},
 	{"wait", no_argument, NULL, 'W'},
@@ -125,21 +128,6 @@ static struct option long_options[] =
 
 
 
-#define T_RUNTIME_OPTIONS_INITIALIZER { \
-		/* configuration metadata */ \
-		false, false, false, false,	\
-		/* general configuration options */	\
-		"", false, "", \
-		/* logging options */ \
-		"", false, false, false, \
-		/* connection options */ \
-		"", \
-		/* node options */ \
-		UNKNOWN_NODE_ID, "", "", \
-		/* event options */ \
-		"", 20, false}
-
-
 static void do_help(void);
 
 static void do_standby_clone(void);