Nginx Quick start

Nginx profile

Nginx(pronounced engine X) is a lightweight, high-performance Web server, reverse proxy server, cache server, E-mail (IMAP/POP3) proxy server based on an asynchronous framework distributed under a BSD-like protocol. Developed by Russian programmer Igor Sysoev, it was originally used by Rambler.ru, a large Russian website, and Rambler, a search engine.

Nginx characteristics

Advantages:

Summary of most prominent advantages: 5W high concurrency, good at handling static files, simple configuration, stable.

  • High concurrency: Developed based on epoll/ Kqueue model,Supports high concurrency“Officials say they support Gundam5wResponse to the number of concurrent connections
  • Less memory consumption:Good at handling static files, consumes less memory and resources than other Web services, such as Apache
  • Simple and stable: Simple configuration (A CONF file), simple to run (Nginx command), and the operation is stable
  • High degree of modularization: function module plug-in design, you can freely configure the corresponding functions.
  • Support for Rwrite rewrite rules: Customized high-quality distribution can be achieved based on key request points such as domain names and urls.
  • Low cost: Nginx’s load balancers are powerful and free and open source, and cost is relatively low compared to hundreds of thousands of hardware load balancers.
  • Support for multiple systems: Nginx code written entirely in C language from scratch, can be compiled and used on various systems.

Disadvantages:

  • Poor dynamic handling: Nginx is good at handling static files, but not as good at handling dynamic pages as heavyweight Web software like Apache.
  • Rewrite is weak: Although Nginx has plenty of support for rewrite, it lacks the capabilities of heavyweight Web software such as Apache.

Nginx deployment

The installation

  1. The installation of the nginx
apt-get install -y build-essential libssl-dev libtool libpcre3 libpcre3-dev make openssl zlib1g-dev 
apt-get install nginx -y
Copy the code
  1. Check the effect
netstat -tnulp | grep nginx
Copy the code
  1. Service related commands
systemctl start|stop|reload|... Nginx start, stop, reload nginx/etc/init. D/nginx start | stop | reload |... /usr/sbin/nginx ... nginx -VCopy the code
  1. Nginx service-related commands
Nginx -v nginx -v nginx -s stop nginx -s reload nginx -t check the default configuration file nginx -t -c file.conf Specifies the configuration file to checkCopy the code
  1. Remove related commands
  • View nginx-related software
dpkg --get-selections|grep nginx
Copy the code
  • Remove nginx, including associated files
apt-get --purge remove nginx
apt-get --purge remove nginx-common
apt-get --purge remove nginx-core
Copy the code

Nginx Configuration Overview

Nginx Software Directory:

  • Working directory: /etc/nginx
  • Execute file: /usr/sbin/nginx
  • Log directory: /var/log/nginx
  • Startup file: / etc/init. D/nginx
  • A web directory:
    • /var/ WWW/HTML/index.nginx-debian.html
    • The home file of /usr/share/nginx/html is index.html

Nginx configuration file:

  • The default file: / etc/nginx/nginx. Conf
  • /etc/nginx/{sites-available/sites-enabled/conf.d}
  • File structure:
    • Global configuration segment
    • The HTTP configuration section
      • Server configuration section project or application
        • Location Indicates the URL of the configuration segment

Nginx access principle

The configuration,(The most important part)

Global configuration segment

The configuration of global and service-level properties is as follows:

User (worker) worker_processes Increases the number of concurrent connections. Keep it consistent with the CPU. Eight-core Settings eight error_log Nginx error log PID PID events when the Nginx service is started Define event-related attributes worker_connections Maximum number of connections a process is allowed to process use Defines the kernel model usedCopy the code

The HTTP configuration section

Configure common configurations of the server

include mime.types; Default_type application/octet-stream; # default file type sendFile on; Enable efficient file transfer mode. autoindex on; # Enable directory list access, suitable for download server, default disabled. tcp_nopush on; Tcp_nodelay on; Keepalive_timeout 120; # long connection timeout, in seconds # Enable gzip compressed outputCopy the code

Common configuration attributes of the Server

Common styles Server {LISTEN port; Server_name Host name; . }Copy the code

The most important attributes of the Server configuration segment are LISTEN and server_name. Both are used to match and process requests.

Listen properties

  • Function: Defines the IP address and port monitored by the Server. The Server performs the next match only when the IP address and port match

  • Form of expression:

In the form of describe The sample Complete sample
IP:Port Address exact representation style Listen 10.10.10.10:99 Listen 10.10.10.10:99
IP Automatic listening IP: address 80 Listen 10.10.10.10 Listen 10.10.10.10:80
Port Automatic listening on the full address :Port Listen or [: :] 99:99 Listen 0.0.0.0:99
default_server The default address is automatically used listen default_server listen localhost:80
  • Principle of use:
    • Server_name = Port = Port = Port = Port = Port = PortA common understanding is that when we match more than one IP:Port, the following Server_name will take effect)
Server_name properties
  • Function: Defines the domain name that the Server listens to. Perform the next step only when the domain name matches
  • Form of expression:
format Complete style Prefix regular style Postfix regular style Prohibit illegal domain names or IP addresses
In the form of www.example.com * .example.com www.example. * _
  • Principle of use:
    • Full styles are preferredAnd then usePrefix regular styleAnd finally usePostfix regular style.If the pattern of the re is the same, the match is the longest, otherwise the rule is illegal.
    • Invalid domain name /IP address: an invalid IP address or domain name is requested from the host
The root attribute
  • Defines the path of the HTML file requested by the Server
  • Form of expression:
root /var/www/html;
Copy the code
The index attribute
  • Purpose: Defines the file name or format to be returned in response to a request
  • Form of expression:
index index.html index.htm index.nginx-debian.html;
Copy the code
The return attribute
  • Purpose: Defines the HTTP status code returned in response to a request
  • Form of expression:
return 444;
Copy the code

Location Common configuration properties

Location responds and processes requests based on the path and keywords matched by the Server.

Grammar:

location optional_modifier location_match { ... } 
location @name { ... }
Copy the code

Optional_modifier is the matching condition, location_match is the matching style, and {} is the operation to be performed.

There are two main matching conditions: regular/prefix characters.

Match rule

  • Regular match
type meaning The matching way priority style
~ |! ~ Ordinary regular – sensitive | not sensitive Regular symbol 3 location ~ .(jpe? g)$ {}
~ * |! ~ * Ordinary regular – not sensitive | sensitive Regular symbol 3 location ~* .(jpe? g)$ {}
  • Ordinary match
type meaning The matching way priority style
= / path An exact match The prefix 1 location = /image {}
^ ~ Give priority to match The prefix 2 location ^~ /page {}
@ Internal redirection The prefix location @name {}
Empty / General matching The prefix 4 location / {}

Principle of use:

  • Prerequisite: Obtain based on the request URLuriThat is, the part other than the domain name /IP used for location matching
  • If there is an exact match, that is, the =/ path, the match ends when a match is found.
    • Location = path {} or location full path {}
  • If there is a priority match, that is, ^~, the match ends after the match is found.
    • The location ^ ~ path
  • If there is a regular match, namely ~ |! ~ * | | ~! ~*. After a match is found, the match will continue until a suitable one is found
    • Location ~* regular character {}
  • If multiple matches are made, the longest location_match is used.

Match the sample

Common examples:

  • The access effect is as follows:
    • Access the root directory /, for examplehttp://a.com/Will match rule A
    • accesshttp://a.com/loginWill match rule B
    • accesshttp://a.com/static/a.htmlWill match rule C
    • accesshttp://a.com/a.gif.http://a.com/b.pngRules D and E are both suitable, and rule D is preferentially used, whilehttp://a.com/static/c.pngRule C is preferentially matched
    • accesshttp://a.com/a.PNGMatches rule E, because rule E is case insensitive.
    • accesshttp://a.com/a.XHTMLUse rule F.
    • accesshttp://a.com/category/id/1111Then rule H is finally matched.

@ name sample

@ is used to define a name location. It is mainly used for internal redirection and cannot be used to process normal requests. Its usage is as follows:

location / { try_files $uri $uri/ @custom } location @custom { # ... Do something # custom named location can't be nested in another location}Copy the code

Note the following about/at the end of the URL:

  1. It does not affect whether the location_match character in location is "/". /user/ equivalent to /user.
  2. Access to the website domain (http://sswang.com/) is not affected by the end of the "/". Because the browser will automatically complete the "/".
  3. For access to the web site domain after the path (http://sswang.com/other/). The slash at the end is important.
  • A “/” at the end of the URL indicates a directory. No “/” indicates a file, and a redirection will occur if the file is not found.
    • /other/ : Indicates that the server automatically searches for the default file in the directory.
    • /other: indicates that the server searches for other files first. If it cannot find other files, the server takes Other as a directory and redirects it to /other/ to find default files in this directory.

Location Common actions:

There are many common functional attributes inside location, such as basic attributes, temporary jumps, access control, directory lists, and so on.

  • Basic attributes
location / {
 root /var/www/html; # specify the path of the file responding to the request
 index index.php index.html index.htm; Specify the default file name to respond to the request
 expires 7d; Specifies the expiration time of the file in response to the request, typically for static files
 try_files $uri $uri/ =404; If there is a file in the path specified by root, return an error
}
Copy the code
  • Temporary jump
location = /test/ {
 return 302 http://sswang.com/; # when accessing the old URL, temporarily jump to the new url, both urls are not invalid
}
Copy the code
  • Access control
location /nginx-status {
 stub_status on; The nginx status page is disabled by default
 allow 192.1688.14.; Allow access address
 deny all; Disable all access by default} Note: This function relies on the ngx_http_stub_status_module module (not installed by default, requires custom installation)Copy the code
  • Directory listing
location /upload {
 alias /var/www/upload; # specify the path to view the file list (absolute path)
 autoindex on; Enable automatic directory indexing
 autoindex_exact_size off; # Default on, display the exact file size (bytes). Off Indicates the approximate file size (kB/MB/...).
 autoindex_localtime on; By default, the file time is GMT. On: displays the server time of the file} Note: The alias does not allow files specified by the index attribute to appear in the directory specified by the index attribute.Copy the code

root VS alias

  • Both root and alias serve the same purposeSpecifies the path to the file used in response to the requestThey are only slightly different
    • Root indicates that location matches the contentRelative paths
    • Alias stands for aAbsolute path and must end with "/"
    • In general, you configure root in location/and alias in location /other
Location /img/ {alias /var/ WWW /image/; }Copy the code
Location /img/ {root /var/ WWW /image; }Copy the code
  • Nginx :/ var/ WWW /image/
  • Nginx :/ var/ WWW /image/img/

Location Core Action

Nginx configuration syntax flexible, very high control system. The try_files directive, named location, was introduced after 0.7 to partially replace the rewrite configuration.

  • Command syntax
try_files file ... uri
try_files file ... =code
Copy the code

Returns the contents of the file. Otherwise, internal redirection (URI) or status code (code) is performed.

  • Common example
Returns the specified URI if it can be found, otherwise returns an error status code404
try_files $uri $uri/ =404; If the specified file can be found1/2.HTML then returns the corresponding content, otherwise returns6.HTML file content try_files1.html 2.html /6.html; Return the specified URI if it can be found, otherwise internally redirect to @backup location try_files $ur@backup;Copy the code

Note: If the last address is a URI, then the URI must exist, otherwise something is wrong