blog20210813-01.bash

$ haproxy -f /path/to/haproxy.cfg -c

blog20210813-02.cfg

defaults
  mode http
  timeout client 10000ms
  timeout connect 3000ms
  timeout server 10000ms    

frontend fe_test
  bind *:8080 
  default_backend be_test

backend be_test
  server my_server 127.0.0.1:8000 chekc

blog20210813-03.bash

$ haproxy -f /tmp/test.cfg -c
Configuration file is valid

blog20210813-04.bash

$ ps
    PID TTY         TIME CMD
   3219 pts/4    00:00:00 bash
  20940 pts/4    00:00:00 ps

blog20210813-08.bash

$ haproxy -f /tmp/test.cfg -c

blog20210813-09.bash

[NOTICE]   (14686) : haproxy version is 2.4.2-1ppa1~focal
[NOTICE]   (14686) : path to executable is /usr/sbin/haproxy
[ALERT]    (14686) : parsing [/tmp/test.cfg:12] : 'server server1' : unknown keyword 'chekc'; did you mean 'check' maybe ?.
[ALERT]    (14686) : Error(s) found in configuration file : /tmp/test.cfg
[ALERT]    (14686) : Fatal errors found in configuration.

blog20210813-10.bash

$ haproxy -f /etc/haproxy/haproxy.cfg -c
Configuration file is valid

blog20210813-11.bash

#!/usr/bin/bash

haproxy -f /path/to/haproxy.cfg -c

if [ $? -eq 0 ]; then
    echo OK 
else
    echo FAIL
fi
FAIL