MDEV-6667 : Improved handling of wsrep-new-cluster option

Code refactoring. Using mysql option handling system to
handle 'wsrep-new-cluster' option.

mysql-test/r/mysqld--help.result

@@ -1091,6 +1091,10 @@ The following options may be given as the first argument:
  Max write set size (bytes)
  --wsrep-mysql-replication-bundle=# 
  mysql replication group commit 
+ --wsrep-new-cluster Bootstrap a cluster. It works by overriding the current
+ value of wsrep_cluster_address. It is recommended not to
+ add this option to the config file as this will trigger
+ bootstrap on every server start.
  --wsrep-node-address=name 
  Node address
  --wsrep-node-incoming-address=name 
@@ -1454,6 +1458,7 @@ wsrep-log-conflicts FALSE
 wsrep-max-ws-rows 131072
 wsrep-max-ws-size 1073741824
 wsrep-mysql-replication-bundle 0
+wsrep-new-cluster FALSE
 wsrep-node-address 
 wsrep-node-incoming-address AUTO
 wsrep-notify-cmd 

sql/mysqld.cc

@@ -386,6 +386,7 @@ static DYNAMIC_ARRAY all_options;
 
 #ifdef WITH_WSREP
 ulong my_bind_addr;
+bool wsrep_new_cluster= false;
 #endif /* WITH_WSREP */
 bool opt_bin_log, opt_bin_log_used=0, opt_ignore_builtin_innodb= 0;
 my_bool opt_log, opt_slow_log, debug_assert_if_crashed_table= 0, opt_help= 0;
@@ -5899,9 +5900,6 @@ int mysqld_main(int argc, char **argv)
     return 1;
   }
 #endif
-#ifdef WITH_WSREP
-  wsrep_filter_new_cluster (&argc, argv);
-#endif /* WITH_WSREP */
 
   orig_argc= argc;
   orig_argv= argv;
@@ -7884,6 +7882,13 @@ struct my_option my_long_options[]=
   {"table_cache", 0, "Deprecated; use --table-open-cache instead.",
    &tc_size, &tc_size, 0, GET_ULONG,
    REQUIRED_ARG, TABLE_OPEN_CACHE_DEFAULT, 1, 512*1024L, 0, 1, 0},
+#ifdef WITH_WSREP
+  {"wsrep-new-cluster", 0, "Bootstrap a cluster. It works by overriding the "
+   "current value of wsrep_cluster_address. It is recommended not to add this "
+   "option to the config file as this will trigger bootstrap on every server "
+   "start.", &wsrep_new_cluster, &wsrep_new_cluster, 0, GET_BOOL, NO_ARG,
+   0, 0, 0, 0, 0, 0},
+#endif
 
   /* The following options exist in 5.6 but not in 10.0 */
   MYSQL_TO_BE_IMPLEMENTED_OPTION("default-tmp-storage-engine"),

sql/wsrep_mysqld.cc

@@ -781,36 +781,6 @@ void wsrep_stop_replication(THD *thd)
   return;
 }
 
-/* This one is set to true when --wsrep-new-cluster is found in the command
- * line arguments */
-static my_bool wsrep_new_cluster= FALSE;
-#define WSREP_NEW_CLUSTER "--wsrep-new-cluster"
-/* Finds and hides --wsrep-new-cluster from the arguments list
- * by moving it to the end of the list and decrementing argument count */
-void wsrep_filter_new_cluster (int* argc, char* argv[])
-{
-  int i;
-  for (i= *argc - 1; i > 0; i--)
-  {
-    /* make a copy of the argument to convert possible underscores to hyphens.
-     * the copy need not to be longer than WSREP_NEW_CLUSTER option */
-    char arg[sizeof(WSREP_NEW_CLUSTER) + 1]= { 0, };
-    strncpy(arg, argv[i], sizeof(arg) - 1);
-    char* underscore(arg);
-    while (NULL != (underscore= strchr(underscore, '_'))) *underscore= '-';
-
-    if (!strcmp(arg, WSREP_NEW_CLUSTER))
-    {
-      wsrep_new_cluster= TRUE;
-      *argc -= 1;
-      /* preserve the order of remaining arguments AND
-       * preserve the original argument pointers - just in case */
-      char* wnc= argv[i];
-      memmove(&argv[i], &argv[i + 1], (*argc - i)*sizeof(argv[i]));
-      argv[*argc]= wnc; /* this will be invisible to the rest of the program */
-    }
-  }
-}
 
 bool wsrep_start_replication()
 {
@@ -834,11 +804,16 @@ bool wsrep_start_replication()
     return true;
   }
 
-  bool const bootstrap(TRUE == wsrep_new_cluster);
-  wsrep_new_cluster= FALSE;
+  bool const bootstrap= wsrep_new_cluster;
 
   WSREP_INFO("Start replication");
 
+  if (wsrep_new_cluster)
+  {
+    WSREP_INFO("'wsrep-new-cluster' option used, bootstrapping the cluster");
+    wsrep_new_cluster= false;
+  }
+
   if ((rcode = wsrep->connect(wsrep,
                               wsrep_cluster_name,
                               wsrep_cluster_address,

sql/wsrep_mysqld.h

@@ -100,6 +100,7 @@ extern my_bool     wsrep_restart_slave;
 extern my_bool     wsrep_restart_slave_activated;
 extern my_bool     wsrep_slave_FK_checks;
 extern my_bool     wsrep_slave_UK_checks;
+extern bool        wsrep_new_cluster;           // bootstrap the cluster ?
 
 enum enum_wsrep_OSU_method { WSREP_OSU_TOI, WSREP_OSU_RSU };
 enum enum_wsrep_sync_wait {
@@ -127,10 +128,6 @@ extern const char* wsrep_provider_vendor;
 int  wsrep_show_status(THD *thd, SHOW_VAR *var, char *buff);
 void wsrep_free_status(THD *thd);
 
-/* Filters out --wsrep-new-cluster oprtion from argv[]
- * should be called in the very beginning of main() */
-void wsrep_filter_new_cluster (int* argc, char* argv[]);
-
 int  wsrep_init();
 void wsrep_deinit(bool free_options);
 void wsrep_recover();