advanced-nginx-cheatsheet

Work In Progress, more explanations will be added soon

Table of content

• Nginx Performance
  • Load-Balancing
    • php-fpm Unix socket
    • php-fpm TCP
    • HTTP load-balancing
  • WordPress Fastcgi cache
    • mapping fastcgi_cache_bypass conditions
    • Define fastcgi_cache settings
    • fastcgi_cache vhost example
• Nginx as a Proxy
  • Simple Proxy
  • Proxy in a subfolder
  • Proxy keepalive for websocket
  • Reverse-Proxy for Apache
• Nginx Security
  • Denying access
    • common backup and archives files
    • Deny access to hidden files & directory
  • Blocking common attacks
    • base64 encoded url
    • javascript eval() url
• Nginx SEO
  • robots.txt location
  • Make a website not indexable
• Nginx Media
  • MP4 stream module
  • WebP images

Nginx Performance

Load-Balancing

php-fpm Unix socket

upstream php {
    least_conn;

    server unix:/var/run/php/php-fpm.sock;
    server unix:/var/run/php/php-two-fpm.sock;

    keepalive 5;
}

php-fpm TCP

upstream php {
    least_conn;

    server 127.0.0.1:9090;
    server 127.0.0.1:9091;

    keepalive 5;
}

HTTP load-balancing

# Upstreams
upstream backend {
    least_conn;

    server 10.10.10.1:80;
    server 10.10.10.2:80;
}

server {

    server_name site.ltd;

    location / {
        proxy_pass http://backend;
        proxy_redirect      off;
        proxy_set_header    Host            $host;
        proxy_set_header    X-Real-IP       $remote_addr;
        proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

WordPress Fastcgi cache

mapping fastcgi_cache_bypass conditions

To put inside a configuration file in /etc/nginx/conf.d/

# do not cache xmlhttp requests
map $http_x_requested_with $http_request_no_cache {
    default 0;
    XMLHttpRequest 1;
}
# do not cache requests for the following cookies
map $http_cookie $cookie_no_cache {
    default 0;
    "~*wordpress_[a-f0-9]+" 1;
    "~*wp-postpass" 1;
    "~*wordpress_logged_in" 1;
    "~*wordpress_no_cache" 1;
    "~*comment_author" 1;
    "~*woocommerce_items_in_cart" 1;
    "~*woocommerce_cart_hash" 1;
    "~*wptouch_switch_toogle" 1;
    "~*comment_author_email_" 1;
}
# do not cache requests for the following uri
map $request_uri $uri_no_cache {
    default 0;
    "~*/wp-admin/" 1;
    "~*/wp-[a-zA-Z0-9-]+.php" 1;
    "~*/feed/" 1;
    "~*/index.php" 1;
    "~*/[a-z0-9_-]+-sitemap([0-9]+)?.xml" 1;
    "~*/sitemap(_index)?.xml" 1;
    "~*/wp-comments-popup.php" 1;
    "~*/wp-links-opml.php" 1;
    "~*/wp-.*.php" 1;
    "~*/xmlrpc.php" 1;
}
# do not cache request with args (like site.tld/index.php?id=1)
map $query_string $query_no_cache {
    default 1;
    "" 0;
}
# map previous conditions with the variable $skip_cache
map $http_request_no_cache$cookie_no_cache$uri_no_cache$query_no_cache $skip_cache {
    default 1;
    0000 0;
}

Define fastcgi_cache settings

To put inside another configuration file in /etc/nginx/conf.d

# FastCGI cache settings
fastcgi_cache_path /var/run/nginx-cache levels=1:2 keys_zone=WORDPRESS:360m inactive=24h max_size=256M;
fastcgi_cache_key "$scheme$request_method$host$request_uri";
fastcgi_cache_use_stale error timeout invalid_header updating http_500 http_503;
fastcgi_cache_methods GET HEAD;
fastcgi_buffers 256 32k;
fastcgi_buffer_size 256k;
fastcgi_connect_timeout 4s;
fastcgi_send_timeout 120s;
fastcgi_busy_buffers_size 512k;
fastcgi_temp_file_write_size 512K;
fastcgi_param SERVER_NAME $http_host;
fastcgi_ignore_headers Cache-Control Expires Set-Cookie;
fastcgi_keep_conn on;
fastcgi_cache_lock on;
fastcgi_cache_lock_age 1s;
fastcgi_cache_lock_timeout 3s;

To work with cookies, you can edit the fastcgi_cache_key. Cookie can be added with variable $cookie_{COOKIE_NAME}. For example, the WordPress plugin Polylang use a cookie named pll_language, so the directive fastcgi_cache_key would be :

fastcgi_cache_key "$scheme$request_method$host$request_uri$cookie_pll_language";

fastcgi_cache vhost example

server {

    server_name domain.tld;

    access_log /var/log/nginx/domain.tld.access.log;
    error_log /var/log/nginx/domain.tld.error.log;

    root /var/www/domain.tld/htdocs;
    index index.php index.html index.htm;

    # add X-fastcgi-cache header to see if requests are cached
    add_header X-fastcgi-cache $upstream_cache_status;

    # default try_files directive for WP 5.0+ with pretty URLs
    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }
    # pass requests to fastcgi with fastcgi_cache enabled
    location ~ \.php$ {
        try_files $uri =404;
        include fastcgi_params;
        fastcgi_pass php;
        fastcgi_cache_bypass $skip_cache;
        fastcgi_no_cache $skip_cache;
        fastcgi_cache WORDPRESS;
        fastcgi_cache_valid 200 30m;
    }
    # block to purge nginx cache with nginx was built with ngx_cache_purge module
    location ~ /purge(/.*) {
        fastcgi_cache_purge WORDPRESS "$scheme$request_method$host$1";
        access_log off;
    }

}

Nginx as a Proxy

Simple Proxy

location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_redirect      off;
        proxy_set_header    Host            $host;
        proxy_set_header    X-Real-IP       $remote_addr;
        proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    }

Proxy in a subfolder

location /folder/ { # The / is important!
        proxy_pass http://127.0.0.1:3000/;# The / is important!
        proxy_redirect      off;
        proxy_set_header    Host            $host;
        proxy_set_header    X-Real-IP       $remote_addr;
        proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    }

Proxy keepalive for websocket

# Upstreams
upstream backend {
    server 127.0.0.1:3000;
    keepalive 5;
}
# HTTP Server
server {
    server_name site.tld;
    error_log /var/log/nginx/site.tld.access.log;
    location / {
        proxy_pass http://backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forward-Proto http;
        proxy_set_header X-Nginx-Proxy true;
        proxy_redirect off;
    }
}

Reverse-Proxy For Apache

server {

    server_name domain.tld;

    access_log /var/log/nginx/domain.tld.access.log;
    error_log /var/log/nginx/domain.tld.error.log;

    root /var/www/domain.tld/htdocs;

    # pass requests to Apache backend
    location / {
        proxy_pass http://backend;
    }
    # handle static files with a fallback
    location ~* \.(ogg|ogv|svg|svgz|eot|otf|woff|woff2|ttf|m4a|mp4|ttf|rss|atom|jpe?g|gif|cur|heic|png|tiff|ico|zip|webm|mp3|aac|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf|swf|webp)$ {
        add_header "Access-Control-Allow-Origin" "*";
        access_log off;
        log_not_found off;
        expires max;
        try_files $uri @fallback;
    }
    # fallback to pass requests to Apache if files are not found
    location @fallback {
        proxy_pass http://backend;
    }
}

Nginx Security

Denying access

common backup and archives files

location ~* "\.(old|orig|original|php#|php~|php_bak|save|swo|aspx?|tpl|sh|bash|bak?|cfg|cgi|dll|exe|git|hg|ini|jsp|log|mdb|out|sql|svn|swp|tar|rdf)$" {
    deny all;
}

Deny access to hidden files & directory

location ~ /\.(?!well-known\/) {
    deny all;
}

Blocking common attacks

base64 encoded url

location ~* "(base64_encode)(.*)(\()" {
    deny all;
}

javascript eval() url

location ~* "(eval\()" {
    deny all;
}

Nginx SEO

robots.txt location

location = /robots.txt {
# Some WordPress plugin gererate robots.txt file
# Refer #340 issue
    try_files $uri $uri/ /index.php?$args @robots;
    access_log off;
    log_not_found off;
}
location @robots {
    return 200 "User-agent: *\nDisallow: /wp-admin/\nAllow: /wp-admin/admin-ajax.php\n";
}

Make a website not indexable

add_header X-Robots-Tag "noindex";

location = /robots.txt {
  return 200 "User-agent: *\nDisallow: /\n";
}

Nginx Media

MP4 stream module

location /videos {
    location ~ \.(mp4)$ {
        mp4;
        mp4_buffer_size       1m;
        mp4_max_buffer_size   5m;
        add_header Vary "Accept-Encoding";
        add_header "Access-Control-Allow-Origin" "*";
        add_header Cache-Control "public, no-transform";
        access_log off;
        log_not_found off;
        expires max;
    }
}

WebP images

Mapping conditions to display WebP images

# serve WebP images if web browser support WebP
map $http_accept $webp_suffix {
   default "";
   "~*webp" ".webp";
}

Set conditional try_files to server WebP image :

• if web browser support WebP
• if WebP alternative exist

# webp rewrite rules for jpg and png images
# try to load alternative image.png.webp before image.png
location /wp-content/uploads {
    location ~ \.(png|jpe?g)$ {
        add_header Vary "Accept-Encoding";
        add_header "Access-Control-Allow-Origin" "*";
        add_header Cache-Control "public, no-transform";
        access_log off;
        log_not_found off;
        expires max;
        try_files $uri$webp_suffix $uri =404;
    }
}