blumeops/fly/nginx.conf

worker_processes auto;

events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    # JSON access log for Alloy to tail → Loki + metric extraction
    log_format json_log escape=json
        '{'
            '"time":"$time_iso8601",'
            '"remote_addr":"$remote_addr",'
            '"client_ip":"$http_fly_client_ip",'
            '"request_method":"$request_method",'
            '"request_uri":"$request_uri",'
            '"status":$status,'
            '"body_bytes_sent":$body_bytes_sent,'
            '"request_time":$request_time,'
            '"upstream_response_time":"$upstream_response_time",'
            '"upstream_cache_status":"$upstream_cache_status",'
            '"http_host":"$http_host",'
            '"http_user_agent":"$http_user_agent"'
        '}';
    access_log /var/log/nginx/access.json.log json_log;

    # Rate limiting zones — define per-service zones as needed
    limit_req_zone $binary_remote_addr zone=general:10m rate=10r/s;

    # Proxy cache: 200MB, evict after 24h of no access
    proxy_cache_path /tmp/cache levels=1:2 keys_zone=services:10m
                     max_size=200m inactive=24h;

    # MagicDNS resolver — using a variable in proxy_pass defers upstream DNS
    # resolution to request time (not config time). Results are cached for
    # 30s per worker to avoid per-request DNS lookups.
    resolver 100.100.100.100 valid=30s;
    resolver_timeout 5s;

    # --- docs.eblu.me (static site) ---
    server {
        listen 8080;
        server_name docs.eblu.me;

        limit_req zone=general burst=20 nodelay;

        # Serve a friendly error page when upstreams are unreachable
        # (indri offline, Tailscale tunnel down, emergency shutoff, etc.)
        # proxy_cache_use_stale still takes priority when cached content exists.
        error_page 502 503 504 /error.html;
        location = /error.html {
            root /usr/share/nginx/html;
            internal;
        }
        location = /_error {
            root /usr/share/nginx/html;
            try_files /error.html =404;
        }

        location / {
            set $upstream_docs https://docs.tail8d86e.ts.net;
            proxy_pass $upstream_docs$request_uri;
            proxy_ssl_verify off;
            proxy_ssl_server_name on;
            proxy_intercept_errors on;

            # Cache aggressively — static site only.
            # Do NOT use these settings for dynamic services.
            proxy_cache services;
            proxy_cache_valid 200 1d;
            proxy_cache_valid 404 1m;
            proxy_cache_use_stale error timeout updating;
            proxy_cache_lock on;

            # Prevent cache-busting: ignore query strings and
            # client cache-control headers.
            # Safe for static sites; breaks dynamic services.
            proxy_cache_key $host$uri;
            proxy_ignore_headers Cache-Control Set-Cookie;

            add_header X-Cache-Status $upstream_cache_status;
        }

    }

    # Catch-all: reject unknown hosts, but serve health check
    server {
        listen 8080 default_server;

        location /healthz {
            return 200 "ok\n";
        }

        location /stub_status {
            stub_status;
            allow 127.0.0.1;
            deny all;
        }

        location / {
            return 444;
        }
    }
}