rgw multisite: obsolete 'radosgw-admin period prepare' command

All that the 'radosgw-admin period prepare' command does is create an
empty period and write it to rados. When we added the staging period
(see 'period get --staging'), uncommitted changes were written to that
instead - so the 'period prepare' command became obsolete. It should be
removed!

Fixes: http://tracker.ceph.com/issues/17387

Reported-by: Casey Bodley <cbodley@redhat.com>
Signed-off-by: Gaurav Kumar Garg <garg.gaurav52@gmail.com>

src/rgw/rgw_admin.cc

@@ -75,7 +75,6 @@ void _usage()
   cout << "  object rm                  remove object\n";
   cout << "  object unlink              unlink object from bucket index\n";
   cout << "  objects expire             run expired objects cleanup\n";
-  cout << "  period prepare             prepare a new period\n";
   cout << "  period delete              delete a period\n";
   cout << "  period get                 get period info\n";
   cout << "  period get-current         get current period info\n";
@@ -558,8 +557,10 @@ static int get_cmd(const char *cmd, const char *prev_cmd, const char *prev_prev_
     if (strcmp(cmd, "list") == 0)
       return OPT_BI_LIST;
   } else if (strcmp(prev_cmd, "period") == 0) {
-    if (strcmp(cmd, "prepare") == 0)
-      return OPT_PERIOD_PREPARE;
+    if (strcmp(cmd, "prepare") == 0) {
+      cerr <<"command is obsolete; please check usage and/or man page" <<std::endl;
+      return 0;
+    }
     if (strcmp(cmd, "delete") == 0)
       return OPT_PERIOD_DELETE;
     if (strcmp(cmd, "get") == 0)
@@ -2492,29 +2493,6 @@ int main(int argc, char **argv)
 
   if (raw_storage_op) {
     switch (opt_cmd) {
-    case OPT_PERIOD_PREPARE:
-      {
-	RGWRealm realm(realm_id, realm_name);
-	int ret = realm.init(g_ceph_context, store);
-	if (ret < 0) {
-	  cerr << "could not init realm " << ": " << cpp_strerror(-ret) << std::endl;
-	  return -ret;
-	}
-	RGWPeriod period;
-	ret = period.init(g_ceph_context, store, realm.get_id(), realm.get_name(), false);
-	if (ret < 0) {
-	  cerr << "failed to init period " << ": " << cpp_strerror(-ret) << std::endl;
-	  return -ret;
-	}
-	ret = period.create();
-	if (ret < 0) {
-	  cerr << "ERROR: couldn't create period " << ": " << cpp_strerror(-ret) << std::endl;
-	  return -ret;
-	}
-	encode_json("period", period, formatter);
-	formatter->flush(cout);
-      }
-      break;
     case OPT_PERIOD_DELETE:
       {
 	if (period_id.empty()) {

src/test/cli/radosgw-admin/help.t

@@ -26,7 +26,6 @@
     object rm                  remove object
     object unlink              unlink object from bucket index
     objects expire             run expired objects cleanup
-    period prepare             prepare a new period
     period delete              delete a period
     period get                 get period info
     period get-current         get current period info