nginx container won't start: "real_ip_header" directive is duplicate in /etc/nginx/conf.d/default.conf:142 about btcpayserver-docker

[dennisreimann]

Can you check that you've configured Cloudflare correctly? The Cloudflare fragemnt is the only occurrence that would lead to this and we haven't seen reports like this before. https://docs.btcpayserver.org/Docker/cloudflare-tunnel/#how-to-use

[orfeas0]

I don't use Cloudflare at all.

[dennisreimann]

Can you check that BTCPAYGEN_ADDITIONAL_FRAGMENTS doesn't contain the Cloudflare fragment?

echo $BTCPAYGEN_ADDITIONAL_FRAGMENTS

[orfeas0]

It doesn't contain cloudflare.

I think it's related to lnd-rest

btcpayserver-docker/Production/nginx.tmpl

Lines 40 to 43 in 6b5841e

	{{ if $container.Env.REAL_IP_HEADER }}
	{{ range $containerNetwork := $container.Networks }}
	set_real_ip_from {{ $containerNetwork.IP }};
	{{ end }}

This snippet generates multiple real_ip_header directives and it breaks nginx.
I removed it and it works fine.
I haven't made a PR because I don't know the implications of removing this.

[dennisreimann]

@NicolasDorier can you shina a light on what might be going on here? The search across all our repos only yields the Cloudflare fragment as defining REAL_IP_HEADER -> https://github.com/search?q=org%3Abtcpayserver+REAL_IP_HEADER&type=code

[NicolasDorier]

sorry about this, I have clightning or lnd, and not experiencign the issue. This is weird..

[NicolasDorier]

@orfeas0 can you share all your nginx?

[NicolasDorier]

@orfeas0 I couldn't find the root cause of your issue, nothing we did have REAL_IP_HEADER set to X-Real-IP. That said, The PR #862 will fix your specific issue.