Explains the simple way to set up a local browser cache in a Nginx server _nginx

Browser caching (Browser Caching) is designed to speed browsing and save network resources, where browsers store recently requested documents on a user's disk.
Nginx can set the header of the browser via the expires directive
Syntax: Expires [Time|epoch|max|off]
Default value: Expires off
Scopes: HTTP, server, location
Use this directive to control the headers of the "Expires" and "Cache-control" in the HTTP answer (play a role in controlling page caching).
You can use a positive or negative number in a time value. The value of the "Expires" header will be obtained by the current system time plus the value you set.
EPOCH specifies that the value of "Expires" is 1 January, 1970, 00:00:01 GMT.
MAX Specifies the value of "Expires" to December 2037 23:59:59 GMT, and the value of "Cache-control" is 10 years.
-1 specifies that the value of "Expires" is the server's current time -1s, which expires forever

Example:
Picture Cache 30 Days

Location ~.*\. (jpg|png|jpeg) $
 {
 expires 30d;
 }

JS CSS Cache one hour

Location ~.*\. (JS|CSS)? $
 {
 expires 1h;
 }

The header information cached by the browser can also be set in Nginx, as follows.

 #配置在server节点下 
 #将favicon. ico is placed in the HTML directory of the Nginx installation directory 
location =/favicon.ico { 
  root html; 
  Index index.html index.htm; 
  Expires 30d; #会同时设置Expires and Cache-control:max-age 
  add_header Pragma Pragma; 
 } 

After the settings are set, the request is viewed through the browser.
Increased the

cache-control:max-age=2592000 
Expires:sun, Nov 2015 01:07:48 GMT 

The cache is in effect.

Attention matters
There are several issues to be aware of when debugging:
Four types of user behavior Impact caching: F5 refresh, F5 Force refresh, click Refresh, Address bar return. will make expires ineffective.