nginx: trust X-Forwarded-For only from TRUSTED_PROXIES (closes #64)

nginx trusted X-Forwarded-For from every RFC1918 address, so a client reaching it from one could write a new address on each request and get a fresh rate-limit allowance. The container's TRUSTED_PROXIES now names the reverse proxies nginx trusts, none by default. bin/entrypoint.sh refuses a value with a character no IP address or CIDR has, and writes one set_real_ip_from line per entry into /etc/nginx/trusted-proxies.conf, which nginx.conf includes. The backend is started with TRUSTED_PROXIES=127.0.0.1/32, since nginx is its only client. The viewport test mounts an empty file there. Model: opus-5-5
2026-09-29 05:16:37 +00:00
parent d2f219ca19
commit 16d01d5326
7 changed files with 76 additions and 23 deletions
@@ -21,10 +21,11 @@ import (
 )

 // defaultTrustedProxies lists the networks whose forwarded
-// headers are honoured by default. It covers the RFC1918
-// ranges (to match nginx.conf) plus IPv4 and IPv6 loopback,
-// because the reverse proxy shares the container and reaches
-// the backend over loopback.
+// headers are honoured by default: IPv4 and IPv6 loopback,
+// for a reverse proxy on the same host, and the RFC1918
+// ranges. The container image does not use it:
+// bin/entrypoint.sh gives the server 127.0.0.1/32, since
+// nginx is its only client there.
 const defaultTrustedProxies = "127.0.0.1/32,::1/128," +
 	"10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"