Add function to safely modify postgresql.auto.conf

This is required for PostgreSQL 12 and later.

configfile-scan.l

@@ -38,6 +38,8 @@ static sigjmp_buf *CONF_flex_fatal_jmp;
 static char *CONF_scanstr(const char *s);
 static int	CONF_flex_fatal(const char *msg);
 
+static bool ProcessConfigFile(FILE *fp, const char *config_file, KeyValueList *contents, t_configuration_options *options, ItemList *error_list, ItemList *warning_list);
+
 %}
 
 %option 8bit
@@ -88,9 +90,20 @@ STRING			\'([^'\\\n]|\\.|\'\')*\'
 
 %%
 
+extern bool
+ProcessRepmgrConfigFile(FILE *fp, const char *config_file, t_configuration_options *options, ItemList *error_list, ItemList *warning_list)
+{
+	return ProcessConfigFile(fp, config_file, NULL, options, error_list, warning_list);
+}
 
 extern bool
-ProcessConfigFile(FILE *fp, const char *config_file, t_configuration_options *options, ItemList *error_list, ItemList *warning_list)
+ProcessPostgresConfigFile(FILE *fp, const char *config_file, KeyValueList *contents, ItemList *error_list, ItemList *warning_list)
+{
+	return ProcessConfigFile(fp, config_file, contents, NULL, error_list, warning_list);
+}
+
+static bool
+ProcessConfigFile(FILE *fp, const char *config_file, KeyValueList *contents, t_configuration_options *options, ItemList *error_list, ItemList *warning_list)
 {
 	volatile bool OK = true;
 	volatile YY_BUFFER_STATE lex_buffer = NULL;
@@ -167,12 +180,21 @@ ProcessConfigFile(FILE *fp, const char *config_file, t_configuration_options *op
 		}
 
 		/* OK, process the option name and value */
+		if (contents != NULL)
+		{
+			key_value_list_replace_or_set(contents,
+										  opt_name,
+										  opt_value);
+		}
 
-		parse_configuration_item(options,
-								 error_list,
-								 warning_list,
-								 opt_name,
-								 opt_value);
+		if (options != NULL)
+		{
+			parse_configuration_item(options,
+									 error_list,
+									 warning_list,
+									 opt_name,
+									 opt_value);
+		}
 
 		/* break out of loop if read EOF, else loop for next line */
 		if (token == 0)

configfile.c

@@ -23,6 +23,9 @@
 #include "configfile.h"
 #include "log.h"
 
+#include <utils/elog.h>
+#include <storage/fd.h>			/* for durable_rename() */
+
 const static char *_progname = NULL;
 char		config_file_path[MAXPGPATH] = "";
 static bool config_file_provided = false;
@@ -462,7 +465,7 @@ _parse_config(t_configuration_options *options, ItemList *error_list, ItemList *
 		exit(ERR_BAD_CONFIG);
 	}
 
-	(void) ProcessConfigFile(fp, config_file_path, options, error_list, warning_list);
+	(void) ProcessRepmgrConfigFile(fp, config_file_path, options, error_list, warning_list);
 
 	fclose(fp);
 
@@ -1800,6 +1803,7 @@ parse_bool(const char *s, const char *config_item, ItemList *error_list)
 	return false;
 }
 
+
 /*
  * Split argument into old_dir and new_dir and append to tablespace mapping
  * list.
@@ -1867,6 +1871,86 @@ tablespace_list_append(t_configuration_options *options, const char *arg)
 }
 
 
+bool
+modify_auto_conf(const char *data_dir)
+{
+	PQExpBufferData auto_conf;
+	PQExpBufferData auto_conf_tmp;
+	PQExpBufferData auto_conf_contents;
+
+	FILE	   *fp;
+	KeyValueList config = {NULL, NULL};
+	KeyValueListCell *cell = NULL;
+
+	initPQExpBuffer(&auto_conf);
+	appendPQExpBuffer(&auto_conf, "%s/%s",
+					  data_dir, PG_AUTOCONF_FILENAME);
+
+	fp = fopen(auto_conf.data, "r");
+
+	if (fp == NULL)
+	{
+		fprintf(stderr, "unable to open \"%s\": %s\n",
+				auto_conf.data,
+				strerror(errno));
+		termPQExpBuffer(&auto_conf);
+		return false;
+	}
+
+	(void) ProcessPostgresConfigFile(fp, auto_conf.data, &config, NULL, NULL);
+
+	fclose(fp);
+
+	initPQExpBuffer(&auto_conf_tmp);
+	appendPQExpBuffer(&auto_conf_tmp, "%s.tmp",
+					  auto_conf.data);
+
+	initPQExpBuffer(&auto_conf_contents);
+
+	/*
+	 * Keep this in sync with src/backend/utils/misc/guc.c:write_auto_conf_file()
+	 */
+	appendPQExpBufferStr(&auto_conf_contents,
+						 "# Do not edit this file manually!\n"
+						 "# It will be overwritten by the ALTER SYSTEM command.\n");
+
+	for (cell = config.head; cell; cell = cell->next)
+	{
+		appendPQExpBuffer(&auto_conf_contents,
+						  "%s = '%s'\n",
+						  cell->key, cell->value);
+	}
+
+	fp = fopen(auto_conf_tmp.data, "w");
+	if (fp == NULL)
+	{
+		fprintf(stderr, "unable to open \"%s\": %s\n",
+				auto_conf_tmp.data,
+				strerror(errno));
+	}
+	else
+	{
+		if (fwrite(auto_conf_contents.data, strlen(auto_conf_contents.data) + 1, 1, fp) != 1)
+		{
+			fclose(fp);
+		}
+		else
+		{
+			fclose(fp);
+
+			(void) durable_rename(auto_conf_tmp.data, auto_conf.data, LOG);
+		}
+	}
+
+	termPQExpBuffer(&auto_conf);
+	termPQExpBuffer(&auto_conf_tmp);
+	termPQExpBuffer(&auto_conf_contents);
+
+	key_value_list_free(&config);
+
+	return true;
+}
+
 
 /*
  * parse_event_notifications_list()
@@ -2043,9 +2127,6 @@ free_parsed_argv(char ***argv_array)
 }
 
 
-
-
-
 bool
 parse_pg_basebackup_options(const char *pg_basebackup_options, t_basebackup_options *backup_options, int server_version_num, ItemList *error_list)
 {

configfile.h

@@ -350,7 +350,10 @@ void		exit_with_cli_errors(ItemList *error_list, const char *repmgr_command);
 void		print_item_list(ItemList *item_list);
 const char *print_connection_check_type(ConnectionCheckType type);
 
+extern bool modify_auto_conf(const char *data_dir);
 
-extern bool ProcessConfigFile(FILE *fp, const char *config_file, t_configuration_options *options, ItemList *error_list, ItemList *warning_list);
+extern bool ProcessRepmgrConfigFile(FILE *fp, const char *config_file, t_configuration_options *options, ItemList *error_list, ItemList *warning_list);
+
+extern bool ProcessPostgresConfigFile(FILE *fp, const char *config_file, KeyValueList *contents, ItemList *error_list, ItemList *warning_list);
 
 #endif							/* _REPMGR_CONFIGFILE_H_ */

repmgr-action-node.c

@@ -71,6 +71,7 @@ do_node_status(void)
 	PQExpBufferData output;
 
 	KeyValueList node_status = {NULL, NULL};
+	KeyValueListCell *cell = NULL;
 	NodeInfoList missing_slots = T_NODE_INFO_LIST_INITIALIZER;
 
 	ItemList	warnings = {NULL, NULL};
@@ -465,8 +466,6 @@ do_node_status(void)
 
 	if (runtime_options.output_mode == OM_CSV)
 	{
-		KeyValueListCell *cell = NULL;
-
 		appendPQExpBuffer(&output,
 						  "\"Node name\",\"%s\"\n",
 						  node_info.node_name);
@@ -540,8 +539,6 @@ do_node_status(void)
 	}
 	else
 	{
-		KeyValueListCell *cell = NULL;
-
 		appendPQExpBuffer(&output,
 						  "Node \"%s\":\n",
 						  node_info.node_name);

repmgr-client.c

@@ -57,6 +57,7 @@
 #include <sys/stat.h>
 #include <signal.h>
 
+
 #include "repmgr.h"
 #include "compat.h"
 #include "controldata.h"
@@ -72,7 +73,6 @@
 
 #include <storage/fd.h>			/* for PG_TEMP_FILE_PREFIX */
 
-
 /* globally available variables *
  * ============================ */
 
@@ -348,7 +348,7 @@ main(int argc, char **argv)
 				 *-------------
 				 */
 
-				/* -D/--pgdata */
+				/* -D/--pgdata/--data-dir */
 			case 'D':
 				strncpy(runtime_options.data_dir, optarg, MAXPGPATH);
 				break;
@@ -804,7 +804,6 @@ main(int argc, char **argv)
 		exit_with_cli_errors(&cli_errors, NULL);
 	}
 
-
 	/*----------
 	 * Determine the node type and action; following are valid:
 	 *

strutil.c

@@ -29,6 +29,9 @@ static int
 xvsnprintf(char *str, size_t size, const char *format, va_list ap)
 __attribute__((format(PG_PRINTF_ATTRIBUTE, 3, 0)));
 
+static void
+_key_value_list_set(KeyValueList *item_list, bool replace, const char *key, const char *value);
+
 static int
 xvsnprintf(char *str, size_t size, const char *format, va_list ap)
 {
@@ -164,16 +167,74 @@ item_list_free(ItemList *item_list)
 void
 key_value_list_set(KeyValueList *item_list, const char *key, const char *value)
 {
-	key_value_list_set_format(item_list, key, "%s", value);
+	_key_value_list_set(item_list, false, key, value);
 	return;
 }
 
 void
-key_value_list_set_format(KeyValueList *item_list, const char *key, const char *value,...)
+key_value_list_replace_or_set(KeyValueList *item_list, const char *key, const char *value)
+{
+	_key_value_list_set(item_list, true, key, value);
+	return;
+}
+
+void
+key_value_list_set_format(KeyValueList *item_list, const char *key, const char *value, ...)
+{
+	va_list		arglist;
+	char formatted_value[MAXLEN];
+
+	va_start(arglist, value);
+	(void) xvsnprintf(formatted_value, MAXLEN, value, arglist);
+	va_end(arglist);
+
+	return _key_value_list_set(item_list, false, key, formatted_value);
+}
+
+static void
+_key_value_list_set(KeyValueList *item_list, bool replace, const char *key, const char *value)
 {
 	KeyValueListCell *cell = NULL;
-	va_list		arglist;
 	int			keylen = 0;
+	int			vallen = 0;
+
+	if (replace == true)
+	{
+		KeyValueListCell *prev_cell = NULL;
+		KeyValueListCell *next_cell = NULL;
+
+
+		for (cell = item_list->head; cell; cell = next_cell)
+		{
+			next_cell = cell->next;
+
+			if (strcmp(cell->key, key) == 0)
+			{
+				if (item_list->head == cell)
+					item_list->head = cell->next;
+
+				if (prev_cell)
+				{
+					prev_cell->next = cell->next;
+
+					if (item_list->tail == cell)
+						item_list->tail = prev_cell;
+				}
+				else if (item_list->tail == cell)
+				{
+					item_list->tail = NULL;
+				}
+
+				pfree(cell->key);
+				pfree(cell->value);
+				pfree(cell);
+			}
+			else
+			{
+				prev_cell = cell;
+			}
+		}
+	}
 
 	cell = (KeyValueListCell *) pg_malloc0(sizeof(KeyValueListCell));
 
@@ -184,17 +245,14 @@ key_value_list_set_format(KeyValueList *item_list, const char *key, const char *
 	}
 
 	keylen = strlen(key);
+	vallen = strlen(value);
 
 	cell->key = pg_malloc0(keylen + 1);
-	cell->value = pg_malloc0(MAXLEN);
+	cell->value = pg_malloc0(vallen + 1);
 	cell->output_mode = OM_NOT_SET;
 
 	strncpy(cell->key, key, keylen);
-
-	va_start(arglist, value);
-	(void) xvsnprintf(cell->value, MAXLEN, value, arglist);
-	va_end(arglist);
-
+	strncpy(cell->value, value, vallen);
 
 	if (item_list->tail)
 		item_list->tail->next = cell;

strutil.h

@@ -119,6 +119,9 @@ extern void
 extern void
 			key_value_list_set(KeyValueList *item_list, const char *key, const char *value);
 
+extern void
+key_value_list_replace_or_set(KeyValueList *item_list, const char *key, const char *value);
+
 extern void
 key_value_list_set_format(KeyValueList *item_list, const char *key, const char *value,...)
 __attribute__((format(PG_PRINTF_ATTRIBUTE, 3, 4)));