Haproxy with Lua Support
Compiling HAProxy with Lua support
Haproxy requires Lua 5.3 or later. Lua version 5.3 is young and you may not find it with many Linux distros. But its very easy to build from source as there are not much dependancies
First download source file for lua from here
| 1 2 3 4 | wget http://www.lua.org/ftp/lua-5.3.3.tar.gz tar –xzf lua–5.3.3.tar.gz cd lua–5.3.3 |
Build it for linux
| 1 | make linux |
Install it
| 1 | make install |
Once installed ,verify the lua version using
| 1 2 3 | # lua -v Lua 5.3.3 Copyright (C) 1994–2016 Lua.org, PUC–Rio |
Install Haproxy
Download the source from here
| 1 2 3 | wget http://www.haproxy.org/download/1.6/src/haproxy-1.6.0.tar.gz tar –xzf haproxy–1.6.0.tar.gz cd haproxy–1.6.0 |
Now you can build it using following command
| 1 | make TARGET=linux2628 USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1 USE_CRYPT_H=1 USE_LIBCRYPT=1 USE_LUA=1 |
Then install haproxy using
| 1 | make install |
Once installed you can verify the haproxy version using
| 1 2 3 | # haproxy -v HA–Proxy version 1.6.0 2015/10/13 Copyright 2000–2015 Willy Tarreau <willy@haproxy.org> |
Here are few example configurations for different haproxy-lua implementations
1. Dynamic backends for different Host headers
Consider the situation you have multiple backend servers for different websites and your loadbalancer has to identify the host header and distribute traffic accordingly
Please check below lua code , which does the vhost-backend mapping
| 1 2 3 4 5 6 7 8 9 10 11 | #cat /scripts/getbackend.lua core.register_fetches(“choose_backend”, function(txn) if txn.sf:req_fhdr(“host”) == ‘test1.com’ then return “backend1” elseif txn.sf:req_fhdr(“host”) == ‘test2.com’ then return “backend2” end return “backend1” end) |
Here is the haproxy config file which uses above lua script
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | global daemon log /dev/log local0 log /dev/log local1 notice maxconn 50000 server–state–base /var/state/haproxy/ # lua-load /scripts/getbackend.lua lua–load /scripts/matchsourceip.lua defaults load–server–state–from–file global log global retries 3 backlog 10000 maxconn 10000 timeout connect 3s timeout client 30s timeout server 30s timeout tunnel 3600s timeout http–keep–alive 1s timeout http–request 15s timeout queue 30s timeout tarpit 60s option redispatch option http–server–close option dontlognull frontend mywebserver_10001 bind *:10001 mode tcp use_backend %[lua.choose_backend] backend backend1 balance roundrobin mode tcp server 192_168_2_16_80 192.168.2.16:80 backend backend2 balance roundrobin mode tcp server 192_168_2_8_80 192.168.2.8:80 |
2. Dynamic backend which matches request’s source IP
Another example, consider the situation you have to route the traffic to multiple backends according to source IP of the incoming request
| 1 2 3 4 5 6 7 8 9 10 11 12 | #cat /scripts/matchsourceip.lua core.register_fetches(“choose_backend”, function(txn) if txn.f:src() == ‘192.168.2.21’ then return “backend1” elseif txn.f:src() == ‘192.168.2.8’ then return “backend2” end return “backend1” end) |
I have posted more sample haproxy-lua scripts here , please checkout.