# https://www.digitalocean.com/community/tools/nginx

user                 www-data;
pid                  /run/nginx.pid;
worker_processes     auto;
worker_rlimit_nofile 65535;

# Load modules
include              /etc/nginx/modules-enabled/*.conf;

events {
    multi_accept       on;
    worker_connections 65535;
}

http {
    charset                utf-8;
    sendfile               on;
    tcp_nopush             on;
    tcp_nodelay            on;
    server_tokens          off;
    log_not_found          off;
    types_hash_max_size    2048;
    types_hash_bucket_size 64;
    client_max_body_size   16M;

    # MIME
    include                mime.types;
    default_type           application/octet-stream;

    # Logging
    access_log             /var/log/nginx/access.log;
    error_log              /var/log/nginx/error.log warn;

    # SSL
    ssl_session_timeout    1d;
    ssl_session_cache      shared:SSL:10m;
    ssl_session_tickets    off;

    # Diffie-Hellman parameter for DHE ciphersuites
    ssl_dhparam            /etc/nginx/dhparam.pem;

    # Mozilla Intermediate configuration
    ssl_protocols          TLSv1.2 TLSv1.3;
    ssl_ciphers            ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;

    # OCSP Stapling
    ssl_stapling           on;
    ssl_stapling_verify    on;

    # Connection header for WebSocket reverse proxy
    map $http_upgrade $connection_upgrade {
        default upgrade;
        ""      close;
    }

    map $remote_addr $proxy_forwarded_elem {

        # IPv4 addresses can be sent as-is
        ~^[0-9.]+$        "for=$remote_addr";

        # IPv6 addresses need to be bracketed and quoted
        ~^[0-9A-Fa-f:.]+$ "for=\"[$remote_addr]\"";

        # Unix domain socket names cannot be represented in RFC 7239 syntax
        default           "for=unknown";
    }

    map $http_forwarded $proxy_add_forwarded {

        # If the incoming Forwarded header is syntactically valid, append to it
        "~^(,[ \\t]*)*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*([ \\t]*,([ \\t]*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*)?)*$" "$http_forwarded, $proxy_forwarded_elem";

        # Otherwise, replace it
        default "$proxy_forwarded_elem";
    }

    # Load configs
    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}