Proxy cache key in Nginx - Mini Project: Build & Apply

Configuring Proxy Cache Key in Nginx

📖 Scenario: You are managing a web server using Nginx. To improve performance, you want to cache responses from a backend server. The cache key determines how Nginx stores and retrieves cached content.In this project, you will configure the proxy_cache_key directive to customize the cache key based on the request URI and a custom header.

🎯 Goal: Build an Nginx configuration snippet that sets a proxy cache key using the request URI and the X-User-Type header. This will help cache different versions of content for different user types.

📋 What You'll Learn

Create a variable called $cache_key that combines $request_uri and the X-User-Type header

Set the proxy_cache_key directive to use the $cache_key variable

Use the proxy_cache_key directive inside the location / block

💡 Why This Matters

🌍 Real World

Web servers often cache content to speed up responses. Using a custom cache key lets you serve different cached content to different users, improving performance and user experience.

💼 Career

Understanding how to configure proxy cache keys is important for DevOps engineers managing web infrastructure to optimize server performance and resource usage.

1

Create the initial Nginx server block

Write an Nginx server block with a location / block that proxies requests to http://backend_server. Use the exact server block syntax shown below.

Nginx

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://backend_server;
        # Your code here
    }
}

Need a hint?

Start by writing a basic server block that listens on port 80 and proxies all requests to http://backend_server.

2

Create a variable combining URI and header

Inside the location / block, create a variable called $cache_key that combines $request_uri and the X-User-Type header using the syntax: set $cache_key "$request_uri:$http_x_user_type";

Nginx

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://backend_server;
        # Create $cache_key variable combining $request_uri and X-User-Type header
        # Your code here
    }
}

Need a hint?

Use the set directive to create a variable combining the URI and the header value.

3

Configure proxy_cache_key directive

Inside the location / block, add the directive proxy_cache_key $cache_key; to use the variable $cache_key as the cache key.

Nginx

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://backend_server;
        set $cache_key "$request_uri:$http_x_user_type";
        # Add proxy_cache_key directive here
        # Your code here
    }
}

Need a hint?

Use the proxy_cache_key directive to specify the cache key variable.

4

Print the final Nginx configuration

Print the entire Nginx server block configuration to verify your setup. Use print() with triple quotes to display the configuration exactly as written.

Nginx

# Print the full Nginx configuration below
# Your code here

Need a hint?

Use a print statement with triple quotes to show the full configuration exactly.