通过日志工作分析日志时，非json日志分析起来比较麻烦。通过以下的配置，可以让生成的日志为json。
log-format {"haproxy_clientIP":"%ci","haproxy_clientPort":"%cp","haproxy_dateTime":"%t","haproxy_frontendNameTransport":"%ft","haproxy_backend":"%b","haproxy_serverName":"%s","haproxy_Tw":"%Tw","haproxy_Tc":"%Tc","haproxy_Tt":"%Tt","haproxy_bytesRead":"%B","haproxy_terminationState":"%ts","haproxy_actconn":%ac,"haproxy_FrontendCurrentConn":%fc,"haproxy_backendCurrentConn":%bc,"haproxy_serverConcurrentConn":%sc,"haproxy_retries":%rc,"haproxy_srvQueue":%sq,"haproxy_backendQueue":%bq,"haproxy_backendSourceIP":"%bi","haproxy_backendSourcePort":"%bp","http_request":%r,"request_headers":"%hrl","response_headers":"%hsl","status_code":"%ST"}
配置实例：
# Global settings
#---------------------------------------------------------------------
global
log 127.0.0.1 local2
log-send-hostname
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 30000
user haproxy
group haproxy
daemon
# turn on stats unix socket
stats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode http
log global
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 50000
#---------------------------------------------------------------------
#---------------------------------------------------------------------
listen myapp1 :22222
mode tcp
option tcplog
log-format {"haproxy_clientIP":"%ci","haproxy_clientPort":"%cp","haproxy_dateTime":"%t","haproxy_frontendNameTransport":"%ft","haproxy_backend":"%b","haproxy_serverName":"%s","haproxy_Tw":"%Tw","haproxy_Tc":"%Tc","haproxy_Tt":"%Tt","haproxy_bytesRead":"%B","haproxy_terminationState":"%ts","haproxy_actconn":%ac,"haproxy_FrontendCurrentConn":%fc,"haproxy_backendCurrentConn":%bc,"haproxy_serverConcurrentConn":%sc,"haproxy_retries":%rc,"haproxy_srvQueue":%sq,"haproxy_backendQueue":%bq,"haproxy_backendSourceIP":"%bi","haproxy_backendSourcePort":"%bp"}
option logasap
balance leastconn
server server1 xx.xx.xx.xx:22222
server server2 xx.xx.xx.xx:22222
server server3 xx.xx.xx.xx:22222
listen myapp2 :22201
mode tcp
option tcplog
log-format {"haproxy_clientIP":"%ci","haproxy_clientPort":"%cp","haproxy_dateTime":"%t","haproxy_frontendNameTransport":"%ft","haproxy_backend":"%b","haproxy_serverName":"%s","haproxy_Tw":"%Tw","haproxy_Tc":"%Tc","haproxy_Tt":"%Tt","haproxy_bytesRead":"%B","haproxy_terminationState":"%ts","haproxy_actconn":%ac,"haproxy_FrontendCurrentConn":%fc,"haproxy_backendCurrentConn":%bc,"haproxy_serverConcurrentConn":%sc,"haproxy_retries":%rc,"haproxy_srvQueue":%sq,"haproxy_backendQueue":%bq,"haproxy_backendSourceIP":"%bi","haproxy_backendSourcePort":"%bp"}
option logasap
balance leastconn
server server1 xx.xx.xx.xx:22201
server server2 xx.xx.xx.xx:22201
server server3 xx.xx.xx.xx:22201
# Interface Web
listen stats *:80
stats enable
stats uri /
stats refresh 5s
stats hide-version