Quoting the GPL FAQ: https://www.gnu.org/licenses/gpl-faq.html
I downloaded just the binary from the net. If I distribute copies, do I have to get the source and distribute that too? (#UnchangedJustBinary)
Yes. The general rule is, if you distribute binaries, you must distribute the complete corresponding source code too. The exception for the case where you received a written offer for source code is quite limited.
I might just have missed the link or place where the code from VSI is hosted.Can I put the binaries on my Internet server and put the source on a different Internet site? (#SourceAndBinaryOnDifferentSites)
Yes. Section 6(d) allows this. However, you must provide clear instructions people can follow to obtain the source, and you must take care to make sure that the source remains available for as long as you distribute the object code.
This doesn't only apply to haproxy but all GPL licensed products provided by VSI, but haproxy is an example I'm familiar with.