Cache Purge#

Allows clearing the cache content.

Loading the Module#

Connecting the module in the context of main{}:

load_module modules/ngx_http_cache_purge_module.so;

Configuration Example#

log_format test_cache '[$time_local] "$request" '
                      '$status $body_bytes_sent rt="$request_time" '
                      'ucs="$upstream_cache_status" us="$upstream_status" '
                      'ubr=$upstream_bytes_received';

proxy_cache_path /var/cache/angie/cache keys_zone=cache_zone:10m;

server {
    listen 80 default_server;

    location / {
        access_log /var/log/angie/cache-access.log test_cache;
        proxy_pass http://127.0.0.1:8080;

        proxy_cache cache_zone;
        proxy_cache_valid 10m;
        proxy_cache_key $uri$is_args$args;
        proxy_cache_purge PURGE from 127.0.0.1;
    }
}

Preparing for Demonstration#

Requesting a file from the server:

$ curl -s -o testf1.txt http://127.0.0.1/storage/testf1.txt

Checking the cache (MISS - file not found in cache):

[05/Mar/2025:17:44:24 +0300] "GET /storage/testf1.txt HTTP/1.1" 200 519 rt="0.001" ucs="MISS" us="200" ubr=752

Re-requesting (HIT - file served from cache):

$ curl -s -o testf1.txt http://127.0.0.1/storage/testf1.txt

[05/Mar/2025:17:46:02 +0300] "GET /storage/testf1.txt HTTP/1.1" 200 519 rt="0.000" ucs="HIT" us="-" ubr=-

Clearing the Cache#

$ curl -X PURGE http://127.0.0.1/storage/*

<html><head><title>Successful purge</title></head><body bgcolor="white"><center><h1>Successful purge</h1><p>Key : /storage/*</p></center></body></html>

Requesting a file after cache clearing (MISS - file loaded again):

$ curl -s -o testf1.txt http://127.0.0.1/storage/testf1.txt

[05/Mar/2025:17:52:05 +0300] "GET /storage/testf1.txt HTTP/1.1" 200 519 rt="0.002" ucs="MISS" us="200" ubr=752

Configuration Example for a Separate Location for Cache Clearing#

proxy_cache_path /var/cache/angie/cache keys_zone=cache_zone:10m;

map $uri $wpurgeuri {
    "~/purge(?<wpurge>/.*)" $wpurge;
    default $uri;
}

server {
    listen 80 default_server;

    location / {
        access_log /var/log/angie/cache-access.log test_cache;
        proxy_pass http://127.0.0.1:8080;

        proxy_cache cache_zone;
        proxy_cache_valid 10m;
        proxy_cache_key $uri$is_args$args;
    }

    location /purge {
        allow 127.0.0.1;
        deny all;
        proxy_cache_purge cache_zone $wpurgeuri$is_args$args;
    }
}

Request for clearing the cache in this case:

$ curl -X PURGE http://127.0.0.1/purge/storage/*

Additional Information#

Full documentation of directives and source code is available at: nginx-modules/ngx_cache_purge