This project acts as a proxy between a Ghost CMS instance and BunnyCDN. It efficiently forwards client requests to Ghost CMS and handles the responses. While doing so, it monitors responses for the X-Cache-Invalidate header, which signals the need to purge the cache.
In this project specifically, it is used to purge the cache of a specified BunnyCDN pull zone. This functionality ensures that the cache remains synchronized with the latest content updates from Ghost CMS.
Additionally, the tool sets the client's IP address as the X-Forwarded-For header in the request to Ghost. This is necessary since Bunny.net tries to set their edge servers' IP addresses as the client's IP address, which can cause issues with Ghost's rate limiting.
Originally developed as part of the BunnyCDN Perma-Cache integration at Magic Pages, a managed Ghost CMS hosting service, this tool can also help self-hosters using BunnyCDN to keep their cache up-to-date with their Ghost CMS instance.
While designed for use within a Docker Compose environment, other usage configurations are technically possible but not tested.
If you don't have BunnyCDN set up yet, you can follow the tutorial on the Magic Pages blog to get started.
The magicpages/bunnycdn-perma-cache-purger Docker image is available on Docker Hub. It can be used to deploy the proxy as part of a Docker Compose stack alongside Ghost.
GHOST_URL: The URL of your Ghost CMS instance. Ideally, the hostname of your Ghost container and the port it listens on (e.g.,http://ghost:2368).BUNNYCDN_API_KEY: Your BunnyCDN API key.BUNNYCDN_PULL_ZONE_ID: The ID of the BunnyCDN pull zone that you wish to purge.
PORT: The port on which the proxy listens for incoming requests. Defaults to3000.DEBUG: Set totrueto enable debug logging. Defaults tofalse.BUNNYCDN_PURGE_OLD_CACHE: Set totrueto enable deleting old cache files from the storage zone.BUNNYCDN_STORAGE_ZONE_NAME: Required ifBUNNYCDN_PURGE_OLD_CACHEis set totrue. The name of the BunnyCDN storage zone connected to the pull zone.BUNNYCDN_STORAGE_ZONE_PASSWORD: Required ifBUNNYCDN_PURGE_OLD_CACHEis set totrue. The password of the BunnyCDN storage zone connected to the pull zone. This differs from the API key. See Bunny's Edge Storage API documentation for more information.- BLOCK_KNOWN_SPAM_REQUESTS: Set to true (default) to block known spam requests. Set to false to disable this feature.
These variables must be set in the Docker Compose file or as part of your Docker container configuration.
The docker-compose.yml is a functional example of how to deploy Ghost, MySQL, and the BunnyCDN Perma-Cache Purger as part of a Docker Compose stack.
version: '3.8'
services:
mysql:
image: mysql:8
environment:
MYSQL_ROOT_PASSWORD: example
MYSQL_DATABASE: ghost
MYSQL_USER: ghost
MYSQL_PASSWORD: ghost
volumes:
- mysql_data:/var/lib/mysql
healthcheck:
test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
interval: 30s
timeout: 10s
retries: 5
start_period: 10s
ghost:
image: ghost:latest
environment:
url: http://localhost:2368
database__client: mysql
database__connection__host: mysql
database__connection__user: ghost
database__connection__password: ghost
database__connection__database: ghost
volumes:
- ghost_data:/var/lib/ghost/content
depends_on:
mysql:
condition: service_healthy
bunnycdn-perma-cache-purger:
image: magicpages/bunnycdn-perma-cache-purger:latest
environment:
GHOST_URL: http://ghost:2368
BUNNYCDN_API_KEY: your_bunnycdn_api_key
BUNNYCDN_PULL_ZONE_ID: your_pull_zone_id
BUNNYCDN_PURGE_OLD_CACHE: "true"
BUNNYCDN_STORAGE_ZONE_NAME: your_storage_zone_name
BUNNYCDN_STORAGE_ZONE_PASSWORD: your_storage_zone_password
depends_on:
ghost:
condition: service_started
ports:
- "2368:3000"
volumes:
ghost_data:
mysql_data:In this example, the Ghost CMS instance is accessible at http://localhost:2368. Port 2368 is usually the default port on which Ghost listens, but since we want to catch the X-Cache-Invalidate header, we don't expose Ghost directly. Instead, the proxy listens on that port and forwards requests to Ghost.
In a nutshell, this proxy forwards all incoming requests to the Ghost instance that's specified in the GHOST_URL environment variable. All responses from Ghost are forwarded back to the client, while the proxy monitors the responses for the X-Cache-Invalidate header.
If the header is present, the proxy sends a purge request to the BunnyCDN API to clear the cache of the specified pull zone. If BUNNYCDN_PURGE_OLD_CACHE is set to true, it also deletes old directories from the specified storage zone to manage storage costs effectively.
The proxy is built using Node.js and a simple Express server. Nothing fancy, just a few lines of code to handle the requests and responses.
And yes, that is the exact code that's running in production at Magic Pages 😉
The BLOCK_KNOWN_SPAM_REQUESTS environment variable allows you to block spam requests targeting Ghost CMS. By default, this feature is enabled. The middleware will inspect incoming requests and block any that match known spam patterns.
| Spam Pattern | Request Property | Value | Description | |
|---|---|---|---|---|
| /members/api/send-magic-link | name | adwdasddwa | Blocks spam signup attempts using this specific name. |
This feature is particularly useful if you're experiencing targeted spam attacks that repeatedly use the same name or other identifying features in the requests. You can extend this table and the corresponding middleware logic as needed to block additional patterns. PRs for other known spam requests are very welcome.
This project is licensed under the MIT License, so feel free to do whatever you want with it. If you find it useful, I'd love to hear about it!
If you have any ideas for improvements or new features, feel free to open an issue or submit a pull request. Always happy to make things even better and more useful!