Sample HAProxy conf with req.body logging

global
    log 127.0.0.1 local0
    user root
    group root
    daemon

defaults
    log     global
    mode    http
    option  httplog
    option  dontlognull
    retries 3
    option redispatch
    timeout connect 5000
    timeout client  120000
    timeout server  90000

frontend www-http
    bind 0.0.0.0:9000

    option http-buffer-request
    declare capture request len 400000
    http-request capture req.body id 0
    log-format {"%[capture.req.hdr(0)]"}

    default_backend node-servers

backend node-servers
    server node google.com:80 maxconn 20

        ## ------ LOG ----------
        #no log  ####this is real line USE THIS to disable log!!! when commented allows log
        mode http
        option http-buffer-request
        declare capture request len 40000000
        http-request capture req.body id 0
        capture request header user-agent len 150
        capture request header Host len 15
        log-format '{"srcIP":"%[src]","backend":"%s","bIP":"%si","bPORT":"%sp","method":"%[capture.req.method]","user-agent":"%[capture.req.hdr(1),json(utf8s)]","uri":"%[capture.req.uri]","body":"%[capture.req.hdr(0)]"}'

        ## --------------------

DONT USE IT IN PRODUCTION! it will kill performance dependent on log method more or less :P Its also not safe and breaks bunch of laws. Remember!

this works for me on haproxy 2.4, thanks