Can't remember where I found the info for this snippet

[xnaas]

(proxyheaders) {
  flush_interval -1
  header_up Host {host}
  header_up X-Real-IP {http.request.header.CF-Connecting-IP}
  header_up X-Forwarded-For {http.request.header.CF-Connecting-IP}
  header_up X-Forwarded-Proto {scheme}
  header_up X-Forwarded-Host {hostpost}
  header_up X-Forwarded-Ssl {on}
}

I know I got the values that go inside {} came from somewhere, but I can’t recall where. I was sure this was on the Caddy docs somewhere, but I can’t find it.

  header_up X-Forwarded-Host {hostpost}

This one looks like it’s probably wrong…which is why I was trying to find this info again.

[francislavoie]

Caddy’s placeholders are a bit fragmented in the documentation, because each execution context may set its own placeholders. Not all placeholders are always available.

Here’s a list of all the HTTP placeholders:

JSON Config Structure - Caddy Documentation

Here’s a list of the Caddyfile placeholder shortcuts (exclusive to the Caddyfile):

Caddyfile Concepts - Caddy Documentation

@xnaas

header_up X-Forwarded-Ssl {on}

Pretty certain {on} does not exist as a placeholder in Caddy.

[matt (Matt Holt)]

To add to this, you also do not need the header_up X-Forwarded-Proto {scheme} line. You should be getting a warning for having that because it’s already set for you.

[xnaas]

@francislavoie

Caddy’s placeholders are a bit fragmented in the documentation, because each execution context may set its own placeholders. Not all placeholders are always available.

Good to know.

@francislavoie

Here’s a list of all the HTTP placeholders:

Here’s a list of the Caddyfile placeholder shortcuts (exclusive to the Caddyfile):

Thank you! Looks like what I recall. Time to actually bookmark them this time…

@francislavoie

Pretty certain {on} does not exist as a placeholder in Caddy.

Looks like not…just copied from nginx along time ago, I guess. Wonder what the equivalent is or if it’s even needed at all.

---

@matt

To add to this, you also do not need the header_up X-Forwarded-Proto {scheme} line. You should be getting a warning for having that because it’s already set for you.

Interesting. Never seen any errors or warnings specifically relevant to it. Currently on v2.3.0 h1:fnrqJLa3G5vfxcxmOH/+kJOcunPLhSBnjgIvjXV/QTA=.

I’ll remove it (and anything else!) that’s superfluous, though. Less stuff = more good.

[francislavoie]

@xnaas

header_up X-Forwarded-Host {hostpost}

Yeah I just realized this is a typo. It’s {hostport} (port, not post).

Also…

@xnaas

header_up Host {host}

This one isn’t useful either, this is already the default behaviour of Caddy.

reverse_proxy (Caddyfile directive) - Caddy Documentation

[xnaas]

@francislavoie

Yeah I just realized this is a typo. It’s {hostport} (port, not post).

That’s what I assumed which is what brought me to making this question/post to begin with haha – darn typos! That’ll teach me to not copy and paste…

Also: thanks for another useful link.

---

Edit: I think it’s simplified to just this now, then:

(proxyheaders) {
  flush_interval -1
  header_up X-Real-IP {http.request.header.CF-Connecting-IP}
  header_up X-Forwarded-For {http.request.header.CF-Connecting-IP}
  header_up X-Forwarded-Host {hostport}
}

[matt (Matt Holt)]

@francislavoie

Also…

@xnaas

header_up Host {host}

This one isn’t useful either, this is already the default behaviour of Caddy.

Technically the default behavior of Caddy’s proxy is to pass the Host header unchanged to the upstream. The {host} placeholder is just the hostname portion, omitting port if any. Slightly different, but only sometimes.

[xnaas]

I’m learning so much today; thank y’all!