Trust forwarded IPs from the host proxy

README.md

@@ -72,6 +72,10 @@ docker compose ps
 By default, the API is available at `http://localhost:17777/api`. Swagger UI is
 available at `http://localhost:17777/api/doc`.
 The default bind address is suitable for a reverse proxy on the Docker host.
+The backend resolves the Docker host gateway when it starts. Uvicorn trusts
+forwarded headers only from this gateway and the loopback interface. This lets
+audit and security records contain the client IP address. Keep `BACKEND_BIND`
+on `127.0.0.1` and let the reverse proxy provide the public endpoint.
 
 ## Store persistent data
 

compose.yaml

@@ -56,6 +56,10 @@ services:
     build:
       context: .
     restart: unless-stopped
+    environment:
+      TRUST_HOST_PROXY: "1"
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     command: ["drivershub", "--config", "/app/config/config.json", "--banner-service-url", "http://bannergen:8700/banner"]
     volumes:
       - ./config:/app/config

docker/entrypoint.sh

@@ -2,6 +2,15 @@
 # Start a compiled program.
 set -eu
 
+if [ "${TRUST_HOST_PROXY:-0}" = "1" ]; then
+    proxy_ip="$(getent ahostsv4 host.docker.internal | sed -n '1{s/[[:space:]].*//;p;}')"
+    if [ -z "$proxy_ip" ]; then
+        echo "Cannot resolve the trusted Docker host gateway." >&2
+        exit 1
+    fi
+    export FORWARDED_ALLOW_IPS="127.0.0.1,$proxy_ip"
+fi
+
 if [ "${1:-}" = "drivershub" ]; then
     shift
     exec /app/drivershub "$@"