FreshRSS Picture Cache with Cloudflare Workers

This is a Cloudflare worker utilizing its Cache API to cache and serve pictures for RSS feeds.

You can use the FreshRSS image cache plugin to rewrite the RSS feeds to this caching URL.

Usage

1. edit wrangler.toml and set its route and fallback figure url. For example:

   route = "https://example.com/piccache"
   
   [vars]
   FALLBACK_FIGURE = "https://http.cat/404.jpg"

   The CF worker will be bind to the route specified, and when unable to retrieve the figure, it will return FALLBACK_FIGURE instead. You may also remove the line of route and it will use *.workers.dev instead.

2. Add secrets of APITOKEN

   Use wrangler secret put APITOKEN to specify the access token. This should be consistent with image cache plugin's access_token.

3. Deploy the worker

   Read this guide.

4. Configure the image cache plugin

   First, upload the plugin FreshRSS image cache plugin to your freshRSS instance with this guide.

   If you use a route like https://example.com/piccache, the image cache plugin should be configured as:

   cache_url: "https://example.com/piccache?url="
   post_url: "https://example.com/piccache"
   access_token: "<AS THE APITOKEN ABOVE>"
   url_encode: true

   If you don't use route and get a *.workers.dev for your worker, the image cache plugin should be configured as:

   cache_url: "https://some.workers.dev/?url="
   post_url: "https://some.workers.dev/"
   access_token: "<AS THE APITOKEN ABOVE>"
   url_encode: true

Additional Headers

Some RSS feeds may mis-configured their figure loading policies, and cannot retrieve the figure without a specific header. Consider add the URL-headers pair to src/index.ts:25.

Reference

Cloudflare Workers Documentation