Request/response transformation in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is request transformation in nginx?

Request transformation in nginx means changing parts of the incoming client request before sending it to the backend server. This can include modifying headers, URLs, or request bodies.

intermediate

How can nginx modify response headers?

Nginx can modify response headers using the proxy_set_header directive for requests or the add_header directive for responses, allowing control over headers sent back to the client.

intermediate

Which nginx module is commonly used for advanced request and response transformations?

The ngx_http_sub_module allows simple text substitutions in response bodies, and the ngx_http_rewrite_module helps rewrite URLs and headers.

beginner

What does the proxy_set_header directive do?

It sets or changes headers in the request sent from nginx to the backend server, allowing you to add or modify headers before forwarding the request.

intermediate

How can you rewrite a URL path in nginx before proxying?

You can use the rewrite directive inside a location block to change the URL path, for example: rewrite ^/oldpath/(.*)$ /newpath/$1 break;.

Which nginx directive is used to change request headers before sending to the backend?

A sub_filter

B add_header

C rewrite

D proxy_set_header

The proxy_set_header directive modifies headers in the request sent to the backend server.

What does the nginx add_header directive do?

A Adds or modifies response headers

B Rewrites URL paths

C Modifies request headers

D Substitutes text in response body

add_header adds or modifies headers in the response sent back to the client.

Which module allows simple text replacement in nginx response bodies?

A ngx_http_rewrite_module

B ngx_http_sub_module

C ngx_http_proxy_module

D ngx_http_headers_module

The ngx_http_sub_module enables text substitution in response bodies.

How do you rewrite a URL path in nginx?

A Using rewrite directive

B Using add_header

C Using proxy_set_header

D Using sub_filter

The rewrite directive changes the URL path before proxying.

What happens if you use proxy_set_header Host $host; in nginx?

A Adds a new header named Host with value $host

B Removes the Host header

C Sets the Host header to the original client host

D Does nothing

It sets the Host header in the proxied request to the value of the original client host.

Explain how nginx can transform both incoming requests and outgoing responses.

Think about directives like proxy_set_header, rewrite, add_header, and sub_filter.

Describe a simple nginx configuration snippet that rewrites a URL path and changes a request header before proxying.

Use rewrite to change URL, proxy_set_header to modify headers, and proxy_pass to forward.