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fix(nginx): use backend hostname in Host header to prevent ALB routing loops #37

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fix(nginx): use backend hostname in Host header to prevent ALB routing loops #37

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4 changes: 3 additions & 1 deletion src/infra/nginx.conf
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Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,9 @@ server {
resolver_timeout 5s;
set $backend_url ${API_BACKEND_URL};
proxy_pass http://$backend_url;
proxy_set_header Host $host;
# Use the backend hostname, not the incoming request's Host.
# Prevents routing loops when an ALB uses Host-based routing.
proxy_set_header Host $backend_url;
Comment on lines +25 to +27

@schivmeister schivmeister Aug 5, 2026

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The suggestion to use $proxy_host won't work -- it's only populated for static upstreams.

@costezki costezki Jul 29, 2026

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But this will have to be tested in the OP Sandbox, right?

@schivmeister schivmeister Aug 5, 2026

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Not possible due to limited subnet. Hence https://github.com/meaningfy-ws/entity-resolution-ops/pull/30.

proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
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