====== haproxy command cheatsheet ======
[[https://docs.haproxy.org/|haproxy official documentation]]

===== start haproxy in the foreground to see the exact error messages =====

<code bash>
$ haproxy -f /etc/haproxy/haproxy.cfg -db

[NOTICE] 300/184912 (7292) : haproxy version is 2.2.9-2+deb11u3
[NOTICE] 300/184912 (7292) : path to executable is /usr/sbin/haproxy
[ALERT] 300/184912 (7292) : Starting frontend http-in: cannot bind socket [10.0.0.49:80]
[ALERT] 300/184912 (7292) : Starting frontend http-in: cannot bind socket [10.0.0.49:443]
[ALERT] 300/184912 (7292) : sendmsg()/writev() failed in logger #1: Connection refused (errno=111)
</code>