# A template: the nginx image renders it into conf.d at container start,
# filling in PORT and nothing else. bin/entrypoint.sh sets PORT and that
# limit.
server {
    listen ${PORT};
    server_name _;

    # Keep the nginx version out of the Server header and error pages.
    server_tokens off;

    root /usr/share/nginx/html;
    index index.html;

    # Trust RFC1918 reverse proxies for X-Forwarded-For
    set_real_ip_from 10.0.0.0/8;
    set_real_ip_from 172.16.0.0/12;
    set_real_ip_from 192.168.0.0/16;
    real_ip_header X-Forwarded-For;
    real_ip_recursive on;

    # Access log to stdout (Docker best practice)
    access_log /dev/stdout combined;
    error_log  /dev/stderr warn;

    location / {
        try_files $uri $uri/ /index.html;
    }

    # Cache static assets aggressively
    location /assets/ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    # netwatch-server, the Go backend, runs in the same container and
    # listens on loopback only: bin/entrypoint.sh starts it on
    # 127.0.0.1:8081. These headers go with every request passed to it.
    # X-Forwarded-For carries only the client address, as resolved by
    # the real IP settings above, and not the chain the request came
    # with: the backend takes the first entry, which a client can write.
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $remote_addr;
    proxy_set_header X-Forwarded-Proto $scheme;

    location /api/ {
        proxy_pass http://127.0.0.1:8081;
    }

    location = /.well-known/healthcheck {
        proxy_pass http://127.0.0.1:8081;
    }
}