[root@ecs-7b55 lua]# cat admin.lua

--[[ $%BEGINLICENSE%$

 Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved.

 This program is free software; you can redistribute it and/or

 modify it under the terms of the GNU General Public License as

 published by the Free Software Foundation; version 2 of the

 License.

 This program is distributed in the hope that it will be useful,

 but WITHOUT ANY WARRANTY; without even the implied warranty of

 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License

 along with this program; if not, write to the Free Software

 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

 02110-1301  USA

 $%ENDLICENSE%$ --]]

function set_error(errmsg)

        proxy.response = {

                type = proxy.MYSQLD_PACKET_ERR,

                errmsg = errmsg or "error"

        }

end

function read_query(packet)

        if packet:byte() ~= proxy.COM_QUERY then

                set_error("[admin] we only handle text-based queries (COM_QUERY)")

                return proxy.PROXY_SEND_RESULT

        end

        local query = packet:sub()

        local rows = { }

        local fields = { }

        if query:lower() == "select * from backends" then

                fields = {

                        { name = "backend_ndx",

                          type = proxy.MYSQL_TYPE_LONG },

                        { name = "address",

                          type = proxy.MYSQL_TYPE_STRING },

                        { name = "state",

                          type = proxy.MYSQL_TYPE_STRING },

                        { name = "type",

                          type = proxy.MYSQL_TYPE_STRING },

                        { name = "uuid",

                          type = proxy.MYSQL_TYPE_STRING },

                        { name = "connected_clients",

                          type = proxy.MYSQL_TYPE_LONG },

                }

                for i = , #proxy.global.backends do

                        local states = {

                                "unknown",

                                "up",

                                "down"

                        }

                        local types = {

                                "unknown",

                                "rw",

                                "ro"

                        }

                        local b = proxy.global.backends[i]

                        rows[#rows + ] = {

                                i,

                                b.dst.name,          -- configured backend address

                                states[b.state + ], -- the C-id is pushed down starting at 0

                                types[b.type + ],   -- the C-id is pushed down starting at 0

                                b.uuid,              -- the MySQL Server's UUID if it is managed

                                b.connected_clients  -- currently connected clients

                        }

                end

        elseif query:lower() == "select * from help" then

                fields = {

                        { name = "command",

                          type = proxy.MYSQL_TYPE_STRING },

                        { name = "description",

                          type = proxy.MYSQL_TYPE_STRING },

                }

                rows[#rows + ] = { "SELECT * FROM help", "shows this help" }

                rows[#rows + ] = { "SELECT * FROM backends", "lists the backends and their state" }

        else

                set_error("use 'SELECT * FROM help' to see the supported commands")

                return proxy.PROXY_SEND_RESULT

        end

        proxy.response = {

                type = proxy.MYSQLD_PACKET_OK,

                resultset = {

                        fields = fields,

                        rows = rows

                }

        }

        return proxy.PROXY_SEND_RESULT

end