reverseproxy: Keep path to unix socket as dial address

[elnoro]

Hello,

This is a fix for #4231. I tried changing the Path variable in different ways but it did not help.

It seems http transport relies on the address in the dial info context var which caused the issue (https://github.com/caddyserver/caddy/blob/master/modules/caddyhttp/reverseproxy/httptransport.go#L181).

I have also added a test for healthchecks to reproduce the bug described in the issue.

[CLAassistant]

All committers have signed the CLA.

[francislavoie]

@ctsrc could you please try out this fix to confirm that it solves the problem for you?

You'll need to build Caddy from source. Clone the repo and checkout this branch elnoro-fix4321 and then run:

$ cd cmd/caddy/
$ go build

If you need plugins, you can add them in cmd/caddy/main.go as imports in there.

Thanks!

[ctsrc]

@francislavoie I will try it later today and let you know

[mohammed90]

Thanks for doing this! This fix is more consistent with the documentation comment on the Address field of DialInfo than before. It says the field follows the same semantics of the address parameter of net.Dial, which in turn expects path on the filesystem for Unix sockets.

[ctsrc]

@francislavoie I tested it now and this fix by @elnoro solves the problem for me 👍🏻

@elnoro thank you very much for fixing this problem 😊

[mholt]

Thanks, this is a subtle difference, appreciate the change.