On Wed, Jan 09, 2013 at 11:01:40PM +0000, Steven Acreman wrote: > We use chef and ohai which talks to AWS to calculate node counts for > servers based off tags and metadata. We then have a cookbook that generates > the haproxy.cfg every time chef runs (on a cron). If the file changes we > reload the config which seems to keep the sessions alive.
Yes it does :-) > There are far simpler ways to achieve the above. For instance a really > simple bash script that echo's static content to haproxy.cfg and the amazon > command line tools feeding a for loop that prints out the server lines with > their options. > > Having said all of this.. I think it would be cool to allow a file based > backend. What I mean by that is that I would prefer to generate backend > files and upon those files changing haproxy would automatically load them. > So for instance on my static backend I may update the static.servers file > which is referenced in haproxy.cfg. I believe you can do similar things > with mod_jdk and apache. I've been thinking for some time about having a "servers" section where we could declare a farm and have all backends use this/these farms. One benefit would be shared checks and another one would be shared maxconns. But that's not always trivial, it needs some more thinking (eg: to arbitrate whom to serve next when maxconn is enforced). However one point of using a dedicated section is that you could load haproxy with 3 files then : haproxy -f global.cfg -f servers.cfg -f services.cfg And voila ! I'm sure we'd have some corner cases if we do this, reason why it still needs some thinking. Anyway, it's still classified as non-urgent in my head :-) Willy
