Posted onAug 8, 2024

Nginx as Reverse Proxy

Reverse Proxy

A reverse proxy sits in front of a server and can

Act as Load Balancer
Protect the origin servers from attacks by hiding it's IP addresses
Cache content for faster performance
Provide SSL encryption and decryption to and from the server

Directive Needed

Nginx usesproxy_pass Directive for configuring reverse proxy.

Syntax: proxy_pass
Request:https://www.example.com

  location /{    proxy_pass http://10.1.1.3:9000/app1}

Nginx uses proxy_pass directory to pass the request to 'example.com' to another server with ip address of10.1.1.3:9000.

Important: When nginx starts connection with another server(backend) with proxy pass. Itcloses the previous connection with the client which results in some request information islost. So one shouldcapture the original details like actual ip address of client, host details etc andforward to the backend server.

Forward client details to backend server via reverse proxy

One need to Redefining Request Headers and forward it to backend server. To redefine request header useproxy_set_header.

Use proxy_set_header

Syntax: proxy_set_header ;

  server{    listen 80;    proxy_set_header Host$host;# replaces host header that comes from client    proxy_set_header X-Real-IP$remote_addr;# captures original ip address of requester and sends it to backend    proxy_set_header X-Forwarded-For$proxy_add_x_forwarded_for;# all the traverse route the request takes    location /{      proxy_pass http://10.1.1.3:9000/app1}}