{"id":249,"date":"2018-02-09T18:49:08","date_gmt":"2018-02-09T10:49:08","guid":{"rendered":"https:\/\/www.techcoil.com\/blog\/?p=249"},"modified":"2021-01-04T11:03:11","modified_gmt":"2021-01-04T03:03:11","slug":"understanding-the-difference-between-the-root-and-alias-directives-in-nginx","status":"publish","type":"post","link":"https:\/\/www.techcoil.com\/blog\/understanding-the-difference-between-the-root-and-alias-directives-in-nginx\/","title":{"rendered":"Understanding the difference between the root and alias directives in Nginx"},"content":{"rendered":"

Nginx<\/a> is a web server that is good for serving as a reverse proxy server<\/a>, load balancer or HTTP cache. <\/p>\n

One of the most important task in configuring Nginx to proxy HTTP<\/a> \/ HTTPS traffic is telling Nginx where to look for files that it needs for serving HTTP \/ HTTPS requests. <\/p>\n

This posts discusses the root<\/code><\/a> and alias<\/code><\/a> directives that we can use in Nginx configuration files for mapping a url from a HTTP request to a file on the server file system.<\/p>\n

Where can we use the root directive?<\/h2>\n

The root<\/code> directive is typically placed in server<\/code><\/a> and location<\/code><\/a> blocks. Placing a root<\/code> directive in the server block makes the root<\/code> directive available to all location<\/code> blocks within the same server block.<\/p>\n

A Nginx configuration example to illustrate how root directive will be applied<\/h3>\n

The following is a set of configurations for illustrating how the root<\/code> directive is applied: <\/p>\n

\r\nserver {\r\n    server_name example.com;\r\n    listen 80;\r\n\r\n    index index.html;\r\n    root \/var\/www\/example.com;\r\n\r\n    location \/ {\r\n        try_files $uri $uri\/ =404;\r\n    }\r\n\r\n    location ^~ \/images {\r\n        root \/var\/www\/static;\r\n        try_files $uri $uri\/ =404;\r\n    }\r\n}\r\n<\/pre>\n
From the configuration above, Nginx will look inside the \/var\/www\/static<\/code><\/strong> directory on the server to look for files to serve HTTP requests made to http:\/\/example.com\/images\/logo.png<\/code><\/strong> or http:\/\/example.com\/images\/funny-monkey.jpg<\/code><\/strong>. <\/p>\n
Nginx will look inside the \/var\/www\/example.com<\/code><\/strong> directory for files to serve HTTP requests made to http:\/\/example.com\/contact.html<\/code><\/strong> or http:\/\/example.com\/about\/us.html<\/code><\/strong>.<\/p>\n
What does the root directive tells Nginx?<\/h2>\n
The root<\/code> directive tells Nginx to take the request url and append it behind the specified directory.<\/p>\n
For example, with the following configuration block:<\/p>\n
\r\nserver {\r\n    server_name example.com;\r\n    listen 80;\r\n\r\n    index index.html;\r\n    root \/var\/www\/example.com;\r\n\r\n    location \/ {\r\n        try_files $uri $uri\/ =404;\r\n    }\r\n\r\n    location ^~ \/images {\r\n        root \/var\/www\/static;\r\n        try_files $uri $uri\/ =404;\r\n    }\r\n}\r\n\r\n<\/pre>\n
Nginx will map the request made to:<\/p>\n