Added script and docs

README.md

@@ -1,4 +1,56 @@
 mysql-proxy-log-error-queries
 =============================
+This is a mysql proxy lua script to log erroneous queries to a predefined table
+
+
+Requirements:
+-------------
+mysql-proxy >= 0.8.2
+
+
+Installation:
+-------------
+Create the following table:
+
+    CREATE TABLE `somedb`.`mysql_error` (
+        `id` int(11) NOT NULL AUTO_INCREMENT,
+        `date` datetime NOT NULL,
+        `err_num` smallint(6) NOT NULL,
+        `err_type` varchar(10) COLLATE utf8_unicode_ci NOT NULL,
+        `err_message` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
+        `problem_query` varchar(8000) COLLATE utf8_unicode_ci NOT NULL,
+        `conn_id` int(11) NOT NULL,
+        PRIMARY KEY (`id`)
+    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
+
+**Change `somedb`.`mysql_error` to match your log destination**
+
+Also adjust this in the lua script.
+
+**Edit the if condition in read_query to match your preferences.**
+
+By default, only queries of the user "someuser" will be logged.
+
+
+Usage:
+------
+1. > \>v0.8.2
+
+    /path/to/mysql-proxy --proxy-lua-script=/path/to/mysql-proxy-log-error-queries.lua
+2. > \>v0.9
+
+    /path/to/mysql-proxy --proxy-lua-script=/path/to/mysql-proxy-log-error-queries.lua --plugins=proxy
+
+By default, mysql-proxy listens on :4040.
+
+**NB: The hostname will always be localhost!**
+
+To connection from the shell to test, use:
+
+    mysql -u username -p --host=127.0.0.1 --port=4040
+
+When using a remote proxy, simply replace `127.0.0.1` with the correct remote address.
+
+
+
 
-log mysql erroneuos queries into a predefined table

mysql-proxy-log-error-queries.lua

@@ -0,0 +1,60 @@
+local err_flag = false
+function read_query( packet )
+    if packet:byte() == proxy.COM_QUERY then
+        local user = proxy.connection.client.username
+        local host = proxy.connection.client.src.name
+--        print(user .. '@' .. host)
+        if --[[true or]] user:lower() == 'someuser' then
+--[[
+--  host will always be localhost because of proxy
+          and not ( host:lower() == 'localhost'
+              or host:lower() == '127.0.0.1' ) then
+]]
+            proxy.queries:append(1, packet, {resultset_is_needed = true})
+            proxy.queries:append(2, string.char(proxy.COM_QUERY) .. "SET @last_query = '" .. string.sub(packet, 2) .. "'", {resultset_is_needed = true} )
+            proxy.queries:append(3, string.char(proxy.COM_QUERY) .. "SHOW WARNINGS", {resultset_is_needed = true} )
+        end
+        return proxy.PROXY_SEND_QUERY
+    end
+end
+
+
+function insert_query(err_t, err_n, err_m)
+  local query = "INSERT INTO `somedb`.`mysql_error` " ..
+    "(`date`, `err_num`,`err_type`, `err_message`, `problem_query`, `conn_id`)" ..
+    "VALUES( NOW(), " ..
+    err_n  ..  "," .. "\"" ..
+    err_t .."\"" .. "," .. "\"" ..
+    err_m .. "\"" .. "," ..
+    "@last_query" .. "," ..
+    proxy.connection.server.thread_id .. ")"
+--    print(query)
+    proxy.queries:append(4, string.char(proxy.COM_QUERY) .. query, {resultset_is_needed = true})
+    return proxy.PROXY_SEND_QUERY
+end
+
+
+function read_query_result(inj)
+    local res = assert(inj.resultset)
+    if inj.id == 1 then
+        err_flag = false
+        if res.query_status == proxy.MYSQLD_PACKET_ERR then
+            err_flag = true
+            return proxy.PROXY_IGNORE_RESULT
+        end
+    elseif inj.id == 2 then
+        return proxy.PROXY_IGNORE_RESULT
+    elseif inj.id == 3 then
+        if err_flag == true then
+            for row in res.rows do
+                proxy.response.type = proxy.MYSQLD_PACKET_ERR
+                proxy.response.errmsg = row[3]
+                insert_query(row[1], row[2], row[3])
+            end
+            return proxy.PROXY_SEND_RESULT
+        end
+        return proxy.PROXY_IGNORE_RESULT
+    elseif inj.id == 4 then
+        return proxy.PROXY_IGNORE_RESULT
+    end
+end