Nginx incorrect locations handling - configuration

How to properly handle all non-existent locations in nginx configuration for php site?
I can figure out 5 possible cases of such locations.
Incorrect files: example.com/notexist.jpg
Incorrect folders: example.com/notexist
Nested incorrect folders: example.com/notexist1/notexist2/..../notexist10000
Combination of (3) and (1): example.com/notexist1/notexist2/..../notexist10000/not.exist.jpg
Non-existent php files: example.com/notexist.php
Is there tiny and powerful solution covering all of these cases?
Also need to avoid checking ANY file and dir (with -d and -f) as it will add CPU and IO overhead.
Thanks in advance!

try_files solves the issue completely for me
location / {
try_files $uri $uri/index.html $uri.html =404;
}
It is also very important to have absolute paths in your not_found_page otherwise page layout will be broken.

in all your 5 cases a 404 would normally be returned, so you can add special handling of all those cases by:
creating a named location
referring to that named location as your 404 error page:
that would yield:
server {
error_page 404 = #errors;
location #fallback {
# do whatever you want to do on faulty reqeusts
}
}

Related

Config nginx for many client projects

We have about 30+ client projects(some are vue projects and other are static html projects), each projects have seperate root directory.
For now nginx is config like, each project has a location.
location ^~ /workspaces/ {
root /var/www/workspace/;
index index.html index.htm;
}
location ^~ /offical/ {
root /var/www/official/;
index index.html index.htm;
}
...
Each time a new client project released, a new location will add to nginx file. I'm afraid of too many location in the nginx file will affect the efficiency of nginx.
How can I simplify the nginx config file for all the client projects. For example with one location location ^~ /web/, then put all the projects under web path.
Best Practice
The best practice is to use separate domain names for each app. This is important from the security perspective, to guard against a cross-site scripting vulnerability in one app having any ill effects on all the other apps, and cookie management.
Performance
However, from the performance perspective, nginx is already highly efficient for such common use cases that you shouldn't worry about having a few extra location or server_name directives:
location
I'd imagine that the prefix-based location search would be done on a prefix-based search tree — https://en.wikipedia.org/wiki/Trie — e.g., it would be highly efficient, where, effectively, each input character in the URL would only be examined once, and each level on the tree would only have a certain limited number of branches.
If you're instead move to use a regex-based approach, then that would be noticeable slower (at least from the performance analysis, you probably won't notice any difference in real use), because then each regular expression would have to be re-evaluated, potentially on the whole input, until a match is found; the complexity being a multiple of the number of regular expressions, times the size of the input URL.
server_name
If you instead move to a server-based definition, based on non-regex server_name specifications, then the matching would be done through a hash-table, which, likewise, is a very efficient operation, where the search would take constant time even on an infinite number of individual server definitions.
Comparison
Which one is more efficient, location or server_name? It is difficult to say for sure without getting into too many details; but I'd imagine that a hash-based search would be more friendly insofar as CPU branch prediction is concerned — https://en.wikipedia.org/wiki/Branch_predictor; but this is getting really into the weeds here, you don't really need to worry about these sorts of things for a webapp. However, I'd still recommend moving to a server-based configuration for security reasons, even if the extra performance benefits are negligible.
tl;dr:
tl;dr: nginx is already highly efficient for your use case as-is, and no further optimisation is required; the best you could do is to make sure that you don't use any regex-based location directives (either at all, or use a ^~ modifier for your prefix-based location directives), because those would be slower than the prefix-based ones; it would also be advisable to switch to server-based configuration for extra security.
References
http://nginx.org/r/location
http://nginx.org/r/server_name
http://nginx.org/docs/hash.html
http://nginx.org/docs/http/server_names.html
http://nginx.org/docs/http/request_processing.html
I usually use dynamic vhosts for ngninx. Therefore you can create a serving directory e.g. /var/www/ and inside define a directory for e.g. every domain of the client projects you want to deploy.
/var/www/domain.tld
/var/www/subdomain.domain.tld
/var/www/otherproject.tld
/var/www/project.tld/public
and then in nginx you define your server-block as follows
server {
# SSL configuration
listen 443 ssl http2 default_server; # managed by Certbot
listen [::]:443 ssl http2 default_server;
set $basepath "/var/www";
server_name ~^(\w+\.)?(?<base>\w+\.\w+)$;
if ( -d $basepath/$host) {
set $rootpath $basepath/$host;
}
if ( -d $basepath/$host/public ) {
set $rootpath $basepath/$host/public;
}
if ( !-d $basepath/$host ) {
set $rootpath $basepath/$base;
return 301 https://$base$request_uri;
}
root $rootpath;
access_log "/var/log/nginx/${host}.access.log";
error_log "/var/log/nginx/error.log" debug;
index index.php index.html index.htm index.nginx-debian.html;
location ~ \.php$ {
include snippets/fastcgi-php.conf;
fastcgi_pass unix:/run/php/php7.2-fpm.sock;
}
This first sets the basepath to /var/www and then tries in order directories in that basepath. If a directory with the domain from which project is accessed exists and serves them from there, if inside is a public folder this one is preferred. If both are not available it redirects to another defined URL.
Furthermore, for every host a different access.log is generated. Unfortunately for the error.log this does not work, hence all errors are gathered in the common error.log.
for specific files you can then filter for extensions etc. to specify how they are served, in the example above of PHP-files, those are served using the php7.2-fpm.

Nginx setup with multiple html files

I have got a website with multiple html files which I want to serve with Nginx.
server {
listen 80;
root /var/www;
location / {
index index.html;
}
location /projects/ {
index projects.html;
}
server_name mylady17.de;
location /shiny/ {
proxy_pass http://104.248.41.231:3838/;
}
}
This is the way it is set up. The index.html works perfectly fine, but however "http://mylady17.de/projects" gives me an error (404, not found). The projects.html file is stored in var/www/ and should work. What am I doing wrong? Why can´t I access the file?
The index directive operates on URIs which end with a / and attempt to locate files by appending the value of the directive to the URI. See this document for details.
So your URI /projects will not invoke the index module. Even if you did use /projects/ instead, the index module would attempt to locate the file at /var/www/projects/projects.html.
To point a single URI to a given file, you can use an exact match location. See this document for details.
For example:
location = /projects {
rewrite ^ /projects.html last;
}
If you did decide to expand this in the future, requiring nginx to search for files by appending .html to the end of the URI, you could use a try_files directive instead. See this document for details.
For example:
location / {
try_files $uri $uri/ $uri.html =404;
}

NGINX remove .html extension

So, I found an answer to removing the .html extension on my page, that works fine with this code:
server {
listen 80;
server_name _;
root /var/www/html/;
index index.html;
if (!-f "${request_filename}index.html") {
rewrite ^/(.*)/$ /$1 permanent;
}
if ($request_uri ~* "/index.html") {
rewrite (?i)^(.*)index\.html$ $1 permanent;
}
if ($request_uri ~* ".html") {
rewrite (?i)^(.*)/(.*)\.html $1/$2 permanent;
}
location / {
try_files $uri.html $uri $uri/ /index.html;
}
}
But if I open mypage.com it redirects me to mypage.com/index
Wouldn't this be fixed by declaring index.html as index? Any help is appreciated.
The "Holy Grail" Solution for Removing ".html" in NGINX:
UPDATED ANSWER: This question piqued my curiosity, and I went on another, more in-depth search for a "holy grail" solution for .html redirects in NGINX. Here is the link to the answer I found, since I didn't come up with it myself: https://stackoverflow.com/a/32966347/4175718
However, I'll give an example and explain how it works. Here is the code:
location / {
if ($request_uri ~ ^/(.*)\.html(\?|$)) {
return 302 /$1;
}
try_files $uri $uri.html $uri/ =404;
}
What's happening here is a pretty ingenious use of the if directive. NGINX runs a regex on the $request_uri portion of incoming requests. The regex checks if the URI has an .html extension and then stores the extension-less portion of the URI in the built-in variable $1.
From the docs, since it took me a while to figure out where the $1 came from:
Regular expressions can contain captures that are made available for later reuse in the $1..$9 variables.
The regex both checks for the existence of unwanted .html requests and effectively sanitizes the URI so that it does not include the extension. Then, using a simple return statement, the request is redirected to the sanitized URI that is now stored in $1.
The best part about this, as original author cnst explains, is that
Due to the fact that $request_uri is always constant per request, and is not affected by other rewrites, it won't, in fact, form any infinite loops.
Unlike the rewrites, which operate on any .html request (including the invisible internal redirect to /index.html), this solution only operates on external URIs that are visible to the user.
What does "try_files" do?
You will still need the try_files directive, as otherwise NGINX will have no idea what to do with the newly sanitized extension-less URIs. The try_files directive shown above will first try the new URL by itself, then try it with the ".html" extension, then try it as a directory name.
The NGINX docs also explain how the default try_files directive works. The default try_files directive is ordered differently than the example above so the explanation below does not perfectly line up:
NGINX will first append .html to the end of the URI and try to serve it. If it finds an appropriate .html file, it will return that file and will maintain the extension-less URI. If it cannot find an appropriate .html file, it will try the URI without any extension, then the URI as a directory, and then finally return a 404 error.
UPDATE: What does the regex do?
The above answer touches on the use of regular expressions, but here is a more specific explanation for those who are still curious. The following regular expression (regex) is used:
^/(.*)\.html(\?|$)
This breaks down as:
^: indicates beginning of line.
/: match the character "/" literally. Forward slashes do NOT need to be escaped in NGINX.
(.*): capturing group: match any character an unlimited number of times
\.: match the character "." literally. This must be escaped with a backslash.
html: match the string "html" literally.
(\?|$): match a literal "?" or the end of the string. This is done to avoid mishandling file names with something after ".html".
The capturing group (.*) is what contains the non-".html" portion of the URL. This can later be referenced with the variable $1. NGINX is then configured to re-try the request (return 302 /$1;) and the try_files directive internally re-appends the ".html" extension so the file can be located.
UPDATE: Retaining the query string
To retain query strings and arguments passed to a .html page, the return statement can be changed to:
return 302 /$1$is_args$args;
This should allow requests such as /index.html?test to redirect to /index?test instead of just /index.
Note that this is considered safe usage of the `if` directive.
From the NGINX page If Is Evil:
The only 100% safe things which may be done inside if in a location context are:
return ...;
rewrite ... last;
Also, note that you may swap out the '302' redirect for a '301'.
A 301 redirect is permanent, and is cached by web browsers and search engines. If your goal is to permanently remove the .html extension from pages that are already indexed by a search engine, you will want to use a 301 redirect. However, if you are testing on a live site, it is best practice to start with a 302 and only move to a 301 when you are absolutely confident your configuration is working correctly.
This has often come up for me as well and due to the configuration at work, location blocks are iffy at best and the / & .php blocks are locked down. Which means that most of the solutions don't work for me.
So here is one that I simplified from the Accepted answer above.
rewrite ^/(.*)\.html /$1/ permanent;
Works great for CMSs, where the underlying framework is generating the pages

General /etc/nginx/vhosts/default - how to specify server wide settings?

From what I see if I write in the /etc/nginx/vhosts/default the effect will be server wide contrary to per domain confs. I can't seem to know how to write a rule to redirect from /index.html or /dir/index.html ro / or /dir/ to have server wide effects.
The thing is that running on CentOS makes files in /home/user/public_html and from nginx I can't see the user part to use it in the root directive. I thought of something like this:
---
server
{
listen 111.111.111.111:80; // fake IP
server_name ""; // this to take in all hosts... ??
root ~^/home/(.*)/public_html; // this (.*) would contain the user part
rewrite ^(.*/)index.(html|htm) http://$host$1 permanent;
}
---
As you can see.. probably.. I'm trying to make that redirect work for all sites without having to manually edit each specific per domain conf file but rather have it in the /etc/nginx/vhosts/default conf file.
Any help is much appreciated :)
Thank you
You probably need something like this
server {
server_name ~^(www\.)?(?<user>.+)\.domain\.com$;
location / {
root /home/$user/public_html;
}
}
Also, you can't use regexes in root cause it's a definition not a match.

Trouble setting expiration for static asset in nginx

I have the following location directive in my nginx config file:
server{
...
location ~* \.js$ {expires 1d;}
...
location / {
...
}
}
I expect a file served by this URL http://www.mydomain.com/javascripts/myfile.js to have an expiration of +1 day, but I am seeing an expiration of +20 years. What am I doing wrong?
It turns out that I was supposed to edit proxy.conf. Once I did that, it worked swimmingly.