Caddy: DNS SRV record based load balancing

[vramanx]

Does caddy support DNS SRV record based load balancing? This will help integrate with orchestrators like Kubernetes and Microsoft Service Fabric

[francislavoie]

See here: https://caddyserver.com/docs/proxy#policies

That mode isn't supported yet, but it could probably be added. Marking this as a feature request. PRs are welcome!

[jungle-boogie]

Wouldn't this also need to be supported by the browser?

https://bugzilla.mozilla.org/show_bug.cgi?id=14328

[francislavoie]

@jungle-boogie I might be wrong but my understanding is that Caddy would do the DNS lookup for the list of services to use as proxy backends. Don't need browser support for that, browser just sees Caddy

[jungle-boogie]

Ah, I think you're right.
I was thinking of setting the DNS records at the DNS level and then have the browser look that up.

[Gufran]

I am going to work on it, my idea is to resolve SRV records for endpoints starting with srv://. any suggestions?

[francislavoie]

@mholt this isn't actually ready to be closed yet. This issue talks about a proxy load balancing policy, whereas the PR was for fastcgi. See my comment here: https://github.com/mholt/caddy/pull/1870#issuecomment-329590425 and @Gufran's response https://github.com/mholt/caddy/pull/1870#issuecomment-329657025 saying he'll work on the proxy implementation next. We should leave this open until he's done that.

[Gufran]

Yes, right. I didn't start working on proxy package because it is not exactly a trivial change like fastcgi, I thought I'd hold off until we are in the clear about fastcgi package in case there is any problem with that change. Now that the other PR is merged I'll implement the changes in proxy package.

[mholt]

Sounds like a great plan, @Gufran - thank you!