Purging cached content in Nginx - Mini Project: Build & Apply

Purging Cached Content in Nginx

📖 Scenario: You manage a website using Nginx as a reverse proxy with caching enabled. Sometimes, you need to clear specific cached content so visitors see the latest updates immediately.

🎯 Goal: Learn how to configure Nginx to allow purging of cached content and test purging a specific cache key.

📋 What You'll Learn

Create a cache zone named my_cache with a 10MB size

Configure a location /purge/ to allow cache purging using the PURGE HTTP method

Write a command to purge the cache for the URL /index.html

Show the output of the purge command

💡 Why This Matters

🌍 Real World

Websites often cache content to speed up delivery. When content changes, purging cache ensures visitors see fresh content immediately.

💼 Career

DevOps engineers and system administrators use cache purging to maintain website performance and content accuracy.

1

Create a cache zone in Nginx

Write the proxy_cache_path directive to create a cache zone named my_cache with a 10MB size and store cache files in /var/cache/nginx.

Nginx

# Your code here

Need a hint?

Use proxy_cache_path with keys_zone=my_cache:10m and max_size=10m.

2

Configure purge location for cache

Add a location /purge/ block that allows the PURGE HTTP method and uses proxy_cache_purge my_cache to purge cached content.

Nginx

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m inactive=60m max_size=10m;

# Your code here

Need a hint?

Use location /purge/ { ... } with proxy_cache_purge my_cache; and allow only localhost to purge.

3

Write the purge command

Write the curl command to send a PURGE request to http://localhost/purge/index.html to clear the cached /index.html content.

Nginx

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m inactive=60m max_size=10m;

location /purge/ {
    allow 127.0.0.1;
    deny all;
    proxy_cache_purge my_cache;
    proxy_cache_purge_method PURGE;
}

# Your code here

Need a hint?

Use curl -X PURGE http://localhost/purge/index.html to purge the cache.

4

Show the purge command output

Run the purge command and print the output. The expected output is HTTP/1.1 200 OK indicating the cache was cleared.

Nginx

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m inactive=60m max_size=10m;

location /purge/ {
    allow 127.0.0.1;
    deny all;
    proxy_cache_purge my_cache;
    proxy_cache_purge_method PURGE;
}

curl -X PURGE http://localhost/purge/index.html

# Your code here

Need a hint?

The purge command should return HTTP/1.1 200 OK if successful.