Before you start playing with NGINX please read an official Beginner’s Guide. It's a great introduction for everyone.
Nginx (/ˌɛndʒɪnˈɛks/ EN-jin-EKS, stylized as NGINX or nginx) is an open source HTTP and reverse proxy server, a mail proxy server, and a generic TCP/UDP proxy server with a strong focus on high concurrency, performance and low memory usage. It is originally written by Igor Sysoev.
For a long time, it has been running on many heavily loaded Russian sites including Yandex, Mail.Ru, VK, and Rambler. At this moment some high-profile companies using NGINX include Cisco, DuckDuckGo, Facebook, GitLab, Google, Twitter, Apple, Intel, and many more. In the September 2019 it was the most commonly used HTTP server (see Netcraft survey).
NGINX is a fast, light-weight and powerful web server that can also be used as a:
So, to be brief, it provides the core of complete web stacks and is designed to help build scalable web applications. When it comes to performance, NGINX can easily handle a huge amount of traffic. The other main advantage of the NGINX is that allows you to do the same thing in different ways.
Unlike traditional HTTP servers, NGINX doesn't rely on threads to handle requests and it was written with a different architecture in mind - one which is much more suitable for nonlinear scalability in both the number of simultaneous connections and requests per second.
NGINX is also known as a Apache Killer (mainly because of its lightness and much less RAM consumption). It is event-based, so it does not follow Apache's style of spawning new processes or threads for each web page request. Generally, it was created to solve the C10K problem.
For me, it is a one of the best and most important service that I used in my SysAdmin career.
These essential documents should be the main source of knowledge for you:
In addition, I would like to recommend three great docs focuses on the concept of the HTTP protocol:
If you love security keep your eye on this one: Cryptology ePrint Archive. It provides access to recent research in cryptology and explores many subjects of security (e.g. Ciphers, Algorithms, SSL/TLS protocols). A great introduction that covers core concepts of cryptography is Practical Cryptography for Developers. I also recommend to read the Bulletproof SSL and TLS. Yep, it's definitely the most comprehensive book about deploying TLS for me.
An obligatory source of knowledge is also the OWASP Cheat Sheet Series. You should ought treat it as an excellent security guidance. Burp Scanner - Issue Definitions introduces you to the web apps and security vulnerabilities. Finally, The Web Security Academy is a free online training center for web application security with high-quality reading materials and interactive labs of varying levels of difficulty. All are really good source to start learning about web application security.
And, of course, always browse official Nginx Security Advisories and CVE databases like CVE Details or CVE - The MITRE Corporation - to stay Up-to-Date on NGINX vulnerabilities.
When I was studying architecture of HTTP servers I became interested in NGINX. As I was going through research, I kept notes. I found a lot of information about it, e.g. forum posts on the web about every conceivable problem was great. However, I've never found one guide that covers the most important things in a suitable form. I was a little disappointed.
I was interested in everything: NGINX internals, functions, security best practices, performance optimisations, tips & tricks, hacks and rules, but for me some of the documents treated the subject lightly.
Of course, NGINX Official Documentation is the best place but I know that we also have other great resources:
These are definitely the best assets for us and in the first place you should seek help there. Moreover, in order to improve your knowledge, please see Books chapter - it contains top literature on NGINX.
For me, however, there hasn't been a truly in-depth and reasonably simple cheatsheet which describe a variety of configurations and important cross-cutting topics for HTTP servers. Configuration of the NGINX can be tricky sometimes and you really need to get into the syntax and concepts to get an understanding tricks, loopholes, and mechanisms. The documentation isn't as pretty as other projects and should certainly include more robust examples.
This handbook is a set of rules and recommendations for the NGINX Open Source HTTP server. It also contains the best practices, notes, and helpers with countless examples. Many of them refer to external resources.
There are a lot of things you can do to improve in your NGINX instance and this guide will attempt to cover as many of them as possible. For the most part, it contains the most important things about NGINX for me. I think the configuration you provided should work without any talisman. That's why I created this repository.
With this handbook you will explore the many features and capabilities of the NGINX. You'll find out, for example, how to testing the performance or how to resolve debugging problems. You will learn configuration guidelines, security design patterns, ways to handle common issues and how to stay out of them. I explained here a few best tips to avoid pitfalls and configuration mistakes.
I added set of guidelines and examples has also been produced to help you administer of the NGINX. They give us insight into NGINX internals also.
Mostly, I apply the rules presented here on the NGINX working as a reverse proxy. However, does not to prevent them being implemented for NGINX as a standalone server.
If you do not have the time to read hundreds of articles (just like me) this multipurpose handbook may be useful. I created it in the hope that it will be useful especially for System Administrators and Experts of Web-based applications.
This handbook does not get into all aspects of NGINX. What's more, some of the things described in this guide may be rather basic because most of us do not configure NGINX every day and it is easy to forget about basic/trivial things. On the other hand, also discusses heavyweight topics so there is something for advanced users. I tried to put external resources in many places in this handbook in order to dispel any suspicion that may exist.
I did my best to make this handbook a single and consistent (but now I know that is really hard). It's organized in an order that makes logical sense to me. I think it can also be a good complement to official documentation and other great documents. Many of the topics described here can certainly be done better or different. Of course, I still have a lot to improve and to do. I hope you enjoy and have fun with it.
Do not treat this handbook and notes written here as revealed knowledge. You should take a scientific approach when reading this document. If you have any doubts and disagree with me, please point out my mistakes. You should to discover cause and effect relationships by asking questions, carefully gathering and examining the evidence, and seeing if all the available information can be combined in to a logical answer.
I create this handbook for one more reason. Rather than starting from scratch in, I putting together a plan for answering your questions to help you find the best way to do things and ensure that you don't repeat my mistakes from the past.
So, what's most important:
Finally, you should know I'm not a NGINX expert but I love to know how stuff works and why work the way they do. I’m not a crypto expert... but I do know the term "elliptic curve" (I really like this quote!). Don't need to be an expert to figure out the reason just got to have used this and not this or why something works this way and not another. It feels good to understand the recommendations and nuances of a topic you’re passionate about.
Remember about the following most important things:
Blindly deploying of the rules described here can damage your web application!
Do not follow guides just to get 100% of something. Think about what you actually do at your server!
Copy-and-paste is not the best way to learn. Think twice before adopting rules from this handbook.
There are no settings that are perfect for everyone.
Always think about what is better and more important for you: security vs usability/compatibility.
Security mainly refers to minimise the risk.
Change one thing may open a whole new set of problems.
Read about how things work and what values are considered secure enough (and for what purposes).
The only correct approach is to understand your exposure, measure and tune.
+ Security is important for ethical reasons. Compliance is important for legal reasons.
+ The key to workplace contentment is understanding they are unrelated to each other.
+ Both are important, but one does not lead to the other (compliance != security).
author: unknown
+ Security is always needed, no matter what type of website it is. It can be static HTML
+ or fully dynamic, an attacker can still inject hostile content into the page in transit
+ to attack the user.
author: Scott Helme
+ Don’t enable older deprecated protocols just because Karen in Florida is still using
+ a PC that she bought back in 2001.
author: thisinterestsmeblog
I think, in the age of phishing, cyber attacks, ransomware, etc., you should take care of security of your infrastructure as hard as possible but don't ever forget about this one...
Lastly, I would like to quote two very important comments found on the web about compliance with the standards and regulations, and essence of a human factor in security:
Regulations that make sense are often not descriptive - capturing the intent and scope of a rule often requires technical expertise. More than that, it's the type of expertise most organisations do not have. And instead of improving themselves, these companies, who may form the grand majority of the industry, petition the regulators to provide a safe checklist of technical mitigations that can be implemented to remain compliant. [...] Instead of doing the right thing and meeting the planned intent, companies are instead ticking nonsensical boxes that the regulators and their auditors demand. Blindly. Mindlessly. Divorced from reality. - by bostik
Whenever considering security, the human factor is nearly always as important or more important than just the technical aspects. Policy and procedures need to consider the human element and try to ensure that these policies and procedures are structured in such a way as to help enable staff to do the right thing, even when they may not fully understand why they need to do it. - by Tim X
A real community, however, exists only when its members interact in a meaningful way that deepens their understanding of each other and leads to learning.
If you find something which doesn't make sense, or something doesn't seem right, please make a pull request and please add valid and well-reasoned explanations about your changes or comments.
Before adding a pull request, please see the contributing guidelines.
This project exists thanks to all the people who contribute.
What needs to be done? Look at the following ToDo list:
New chapters:
Existing chapters:
If you have any idea, send it back to me or add a pull request.
GitHub exposes an RSS/Atom feed of the commits, which may also be useful if you want to be kept informed about all changes.
This checklist was the primary aim of the nginx-admins-handbook. It contains a set of best practices and recommendations on how to configure and maintain the NGINX properly.
This checklist contains all rules (79) from this handbook.
Generally, I think that each of these principles is important and should be considered. I separated them into four levels of priority to help guide your decision.
PRIORITY | NAME | AMOUNT | DESCRIPTION |
---|---|---|---|
critical | 33 | definitely use this rule, otherwise it will introduce high risks of your NGINX security, performance, and other | |
major | 26 | it's also very important but not critical, and should still be addressed at the earliest possible opportunity | |
normal | 12 | there is no need to implement but it is worth considering because it can improve the NGINX working and functions | |
minor | 8 | as an option to implement or use (not required) |
Remember, these are only guidelines. My point of view may be different from yours so if you feel these priority levels do not reflect your configurations commitment to security, performance or whatever else, you should adjust them as you see fit.
RULE | CHAPTER | PRIORITY |
---|---|---|
Define the listen directives with address:port pairPrevents soft mistakes which may be difficult to debug. | Base Rules | |
Prevent processing requests with undefined server namesIt protects against configuration errors, e.g. traffic forwarding to incorrect backends. | Base Rules | |
Never use a hostname in a listen or upstream directivesWhile this may work, it will comes with a large number of issues. | Base Rules | |
Set the HTTP headers with add_header and proxy_*_header directives properlySet the right security headers for all contexts. | Base Rules | |
Configure log rotation policySave yourself trouble with your web server: configure appropriate logging policy. | Base Rules | |
Use simple custom error pagesDefault error pages reveals information which leads to information leakage vulnerability. | Base Rules | |
Use HTTP/2HTTP/2 will make our applications faster, simpler, and more robust. | Performance | |
Always keep NGINX up-to-dateUse newest NGINX package to fix vulnerabilities, bugs, and to use new features. | Hardening | |
Run as an unprivileged userUse the principle of least privilege. This way only master process runs as root. | Hardening | |
Protect sensitive resourcesHidden directories and files should never be web accessible. | Hardening | |
Take care about your ACL rulesTest your access-control lists and to stay secure. | Hardening | |
Hide upstream proxy headersDon't expose what version of software is running on the server. | Hardening | |
Remove support for legacy and risky HTTP request headersSupports for the offending headers should be removed. | Hardening | |
Force all connections over TLSProtects your website for handle sensitive communications. | Hardening | |
Use min. 2048-bit for RSA and 256-bit for ECC2048 bit (RSA) or 256 bit (ECC) keys are sufficient for commercial use. | Hardening | |
Keep only TLS 1.3 and TLS 1.2Use TLS with modern cryptographic algorithms and without protocol weaknesses. | Hardening | |
Use only strong ciphersUse only strong and not vulnerable cipher suites. | Hardening | |
Use more secure ECDH CurveUse ECDH Curves with according to NIST recommendations. | Hardening | |
Use strong Key Exchange with Perfect Forward SecrecyEstablishes a shared secret between two parties that can be used for secret communication. | Hardening | |
Defend against the BEAST attackThe server ciphers should be preferred over the client ciphers. | Hardening | |
Enable HTTP Strict Transport SecurityTells browsers that it should only be accessed using HTTPS, instead of using HTTP. | Hardening | |
Reduce XSS risks (Content-Security-Policy)CSP is best used as defence-in-depth. It reduces the harm that a malicious injection can cause. | Hardening | |
Control the behaviour of the Referer header (Referrer-Policy)The default behaviour of referrer leaking puts websites at risk of privacy and security breaches. | Hardening | |
Provide clickjacking protection (X-Frame-Options)Defends against clickjacking attack. | Hardening | |
Prevent some categories of XSS attacks (X-XSS-Protection)Prevents to render pages if a potential XSS reflection attack is detected. | Hardening | |
Prevent Sniff Mimetype middleware (X-Content-Type-Options)Tells browsers not to sniff MIME types. | Hardening | |
Reject unsafe HTTP methodsOnly allow the HTTP methods for which you, in fact, provide services. | Hardening | |
Prevent caching of sensitive dataIt helps to prevent critical data (e.g. credit card details, or username) leaked. | Hardening | |
Limit concurrent connectionsLimit concurrent connections to prevent a rogue guys from repeatedly connecting to and monopolizing NGINX. | Hardening | |
Use pass directive compatible with backend protocolSet pass directive only to working with compatible backend layer protocol. | Reverse Proxy | |
Set properly values of the X-Forwarded-For headerIdentify clients communicating with servers located behind the proxy. | Reverse Proxy | |
Don't use X-Forwarded-Proto with $scheme behind reverse proxyPrevent pass incorrect value of this header. | Reverse Proxy | |
Always use $request_uri instead of $uri in proxy_passYou should always pass unchanged URI to the backend layer. | Reverse Proxy | |
Organising Nginx configurationWell organised code is easier to understand and maintain. | Base Rules | |
Format, prettify and indent your Nginx codeFormatted code is easier to maintain, debug, and can be read and understood in a short amount of time. | Base Rules | |
Use reload option to change configurations on the flyGraceful reload of the configuration without stopping the server and dropping any packets. | Base Rules | |
Use return directive for URL redirection (301, 302)The by far simplest and fastest because there is no regexp that has to be evaluated. | Base Rules | |
Maintaining SSL sessionsImproves performance from the clients’ perspective. | Performance | |
Enable OCSP StaplingEnable to reduce the cost of an OCSP validation. | Performance | |
Use exact names in a server_name directive if possibleHelps speed up searching using exact names. | Performance | |
Avoid checks server_name with if directiveIt decreases NGINX processing requirements. | Performance | |
Use $request_uri to avoid using regular expressionsBy default, the regex is costly and will slow down the performance. | Performance | |
Use try_files directive to ensure a file existsUse it if you need to search for a file, it saving duplication of code also. | Performance | |
Use return directive instead of rewrite for redirectsUse return directive to more speedy response than rewrite. | Performance | |
Enable PCRE JIT to speed up processing of regular expressionsNGINX with PCRE JIT is much faster than without it. | Performance | |
Activate the cache for connections to upstream servers Nginx can now reuse its existing connections (keepalive) per upstream. | Performance | |
Disable unnecessary modulesLimits vulnerabilities, improve performance and memory efficiency. | Hardening | |
Hide Nginx version numberDon't disclose sensitive information about NGINX. | Hardening | |
Hide Nginx server signatureDon't disclose sensitive information about NGINX. | Hardening | |
Use only the latest supported OpenSSL versionStay protected from SSL security threats and don't miss out of new features. | Hardening | |
Prevent Replay Attacks on Zero Round-Trip Time0-RTT is disabled by default but you should know that enabling this option creates a significant security risks. | Hardening | |
Mitigation of CRIME/BREACH attacksDisable HTTP compression or compress only zero sensitive content. | Hardening | |
Deny the use of browser features (Feature-Policy)A mechanism to allow and deny the use of browser features. | Hardening | |
Control Buffer Overflow attacksPrevents errors are characterised by the overwriting of memory fragments of the NGINX process. | Hardening | |
Mitigating Slow HTTP DoS attacks (Closing Slow Connections)Prevents attacks in which the attacker sends HTTP requests in pieces slowly. | Hardening | |
Set and pass Host header only with $host variableUse of the $host is the only one guaranteed to have something sensible. | Reverse Proxy | |
Always pass Host, X-Real-IP, and X-Forwarded headers to the backendIt gives you more control of forwarded headers. | Reverse Proxy | |
Set the certificate chain correctlySend the complete chain to the client. | Others | |
Enable DNS CAA PolicyAllows domain name holders to indicate to CA whether they are authorized to issue digital certificates. | Others | |
Separate listen directives for 80 and 443 portsHelp you maintain and modify your configuration. | Base Rules | |
Use only one SSL config for the listen directivePrevents multiple configurations on the same listening address. | Base Rules | |
Use geo/map modules instead of allow/denyProvides the perfect way to block invalid visitors. | Base Rules | |
Set global root directory for unmatched locationsSpecifies the root directory for an undefined locations. | Base Rules | |
Don't duplicate index directive, use it only in the http blockWatch out for duplicating the same rules. | Base Rules | |
Adjust worker processesYou can adjust this value to maximum throughput under high concurrency. | Performance | |
Make an exact location match to speed up the selection processExact location matches are often used to speed up the selection process. | Performance | |
Use limit_conn to improve limiting the download speedLimits NGINX download speed per connection. | Performance | |
Be careful with trailing slashes in proxy_pass directiveIncorrect setting could end up with some strange url. | Reverse Proxy | |
Use custom headers without X- prefixThe use of custom headers with X- prefix is discouraged. | Reverse Proxy | |
Tweak passive health checksImprove behaviour of the passive health checks. | Load Balancing | |
Define security policies with security.txtHelps make things easier for companies and security researchers. | Others | |
Map all the things...Map module provides a more elegant solution for clearly parsing a big list of regexes. | Base Rules | |
Use custom log formatsThis is extremely helpful for debugging specific location directives. | Debugging | |
Use debug mode to track down unexpected behaviourThere's probably more detail than you want, but that can sometimes be a lifesaver. | Debugging | |
Improve debugging by disable daemon, master process, and all workers except oneThis simplifies the debugging and lets test configurations rapidly. | Debugging | |
Use core dumps to figure out why NGINX keep crashingEnable core dumps when your NGINX instance receive an unexpected error or when it crashed. | Debugging | |
Use mirror module to copy requests to another backendUse mirroring for investigation and debugging of any original request. | Debugging | |
Don't disable backends by comments, use down parameterIs a good solution to marks the server as permanently unavailable. | Load Balancing | |
Use tcpdump to diagnose and troubleshoot the HTTP issuesUse tcpdump to monitor HTTP. | Others |
You can find here a few of the different things I've worked and included to this repository. I hope that these extras will be useful.
Many of these recipes have been applied to the configuration of my old private website.
An example configuration is in the configuration examples chapter. It's also based on this version of printable high-res hardening cheatsheets.
Read about SSL Labs grading here (SSL Labs Grading 2018).
Short SSL Labs grades explanation:
A+ is clearly the desired grade, both A and B grades are acceptable and result in adequate commercial security. The B grade, in particular, may be applied to configurations designed to support very wide audiences (for old clients).
I finally got A+ grade and following scores:
Look also at the following recommendations. I believe the right configuration of NGINX should give the following SSL Labs scores and provides the best security for the most cases:
Recommended
Perfect but restrictive
Something about SSL Labs grading mechanism (that's an interesting point of view):
The whole grading mechanism is more propaganda and public relations than actual security. If you want good security, then you must mind the details and understand how things work internally. If you want a good grade then you should do whatever it takes to have a good grade. An "A+" from SSL Labs is a very nifty thing to add at the end of a report, but it does not really equate with having rock solid security. Having an "A+" equates with being able to say "I have an A+". - from this answer by Tom Leek.
Read about Mozilla Observatory here and about Observatory Scoring Methodology.
I also got the highest summary note (A+) on the Observatory with a very high test score (120/100, max. 135/100):
I created two versions of printable posters with hardening cheatsheets (High-Res 5000x8800) based on recipes from this handbook:
For
xcf
and
A+ with all 100%’s on @ssllabs and 120/100 on @mozilla observatory:
It provides the highest scores of the SSL Labs test. Setup is very restrictive with 4096-bit private key, only TLS 1.2, and also modern strict TLS cipher suites (non 128-bits). Think carefully about its use (no TLS 1.3, restrictive cipher suites), in my opinion, it is only suitable for obtaining the highest possible rating and seems a little impractical.
A+ on @ssllabs and 120/100 on @mozilla observatory with TLS 1.3 support:
It provides less restrictive setup with 2048-bit key for
RSA
or 256-bit key forECC
, TLS 1.3 and 1.2, modern strict TLS cipher suites (128/256-bits), and 2048-bit predefinedDH
groups recommended by Mozilla. The final grade is also in line with the industry standards and guidance. Recommend using this, for me, it is very reasonable configuration.
I created a set of scripts for unattended installation of NGINX from the raw, uncompiled code. It allows you to easily install, create a setup for dependencies (like zlib
or openssl
), and customized with installation parameters.
For more information please see Installing from source - Automatic installation chapter which describes the installation of NGINX on systems/distros such as Ubuntu, Debian, CentOS, and FreeBSD.
I created a simple to use generator for static pages to replace the default error pages that comes with any web server like NGINX.
For more information please see HTTP Static Error Pages Generator.
I added scripts for fast multiple domain searching in the configuration. These tools get specific server_name
matches and print them on the screen as a server { ... }
blocks. Both are very helpful if you really have tons of domains or if you want to list specific vhosts from file or the active configuration.
You must follow one important rule to be able to use it. Your server block must have the following structure:
server {
server_name example.com example.org;
... # other directives
}
Example of use:
./snippets/server-name-parser/check-server-name.sh example.com
Searching 'example.com' in '/usr/local/etc/nginx' (from disk)
/usr/local/etc/nginx/domains/example.com/servers.conf:79: return 301 https://example.com$request_uri;
/usr/local/etc/nginx/domains/example.com/servers.conf:252: return 301 https://example.com$request_uri;
/usr/local/etc/nginx/domains/example.com/servers.conf:3825: server_name example.com;
Searching 'example.com' in server contexts (from a running process)
>>>>>>>>>> BEG >>>>>>>>>>
server {
include listen/192.168.252.10/https.example.com.conf;
server_name example.com;
location / {
return 204 "RFC 792";
}
access_log /var/log/nginx/example.com/access.log standard;
error_log /var/log/nginx/example.com/error.log warn;
}
<<<<<<<<<< END <<<<<<<<<<
For more information please see snippets/server-name-parser directory.
Authors: Valery Kholodkov
Excel in Nginx quickly by learning to use its most essential features in real-life applications.
This short review comes from this book or the store.
Authors: Derek DeJonghe
You’ll find recipes for:
This short review comes from this book or the store.
Authors: Martin Fjordvald, Clement Nedelcu
Harness the power of Nginx to make the most of your infrastructure and serve pages faster than ever.
This short review comes from this book or the store.
Authors: Rahul Sharma
Optimize NGINX for high-performance, scalable web applications.
This short review comes from this book or the store.
Authors: Dimitri Aivaliotis
Written for experienced systems administrators and engineers, this book teaches you from scratch how to configure Nginx for any situation. Step-by-step instructions and real-world code snippets clarify even the most complex areas.
This short review comes from this book or the store.
Authors: Faisal Memon, Owen Garrett, Michael Pleshakov
Learn in this ebook how to get started with ModSecurity, the world’s most widely deployed web application firewall (WAF), now available for NGINX and NGINX Plus.
This short review comes from this book or the store.
Authors: Faisal Memon
This ebook provides step-by-step instructions on replacing Cisco ACE with NGINX and off-the-shelf servers. NGINX helps you cut costs and modernize.
In this ebook you will learn:
This short review comes from this book or the store.
Go back to the Table of Contents or read the next chapters:
Introduction to HTTP.
Introduction to SSL/TLS.
Introduction and explanation of the NGINX mechanisms.
One-liners, commands, utilities for building NGINX, and more.
The basic set of rules to keep NGINX in a good condition.
A few things for troubleshooting configuration problems.
Many methods to make sure the NGINX as fast as possible.
Security and hardening methods in line with best practices.
A few rules about the NGINX proxy server.
Some rules to improve NGINX as a load balancer.
Other interesting rules, not necessarily linked to NGINX.
Here are some configuration examples.