Just put
http://nd-build-01.linux-appliance.net/repos/centos/haproxy/haproy-centos-6x.repo
under /etc/yum.repos.d/
and issue yum install haproxy.
of course you do trust the security of your entire server on this repo
? before doing that just be sure of what this implies :)
there is no issue on trusting someone but remember that you trust this
someone to install software as root on your server and update the
package when new version comes.
Do a minimum homework before authorizing repos. I do trust the debian
team for backported 1.5 haproxy package but nevertheless i asked here if
they were legit , verified what i could and limited the package i
accept from the repo to a minimum just in case. I think the same goes on
for centOS/Redhat repos, do chack the source and if not sure build
yourself if there is no official sources.
regards,
Ghislain.