Restricted domains disabled by default. This means that you can fetch a resource from any URL. To enable the domain restriction, change in config/parameters.yml

restricted_domains: true

After enabling, you need to put the white listed domains

whitelist_domains:
  - www.domain-1.org
  - www.domain-2.org

Based on this RFC Signature Generation was added to Flyimg in order to avoid DDOS attacks.

First you need to edit security_key and security_iv in parameters.yml file and add a proper values. Than any request to Fyimg app will throw an error unless it's encrypted.

To generate the encrypted url you need to run this command:

docker exec flyimg php app.php encrypt w_200,h_200,c_1/https://mudawn.com/assets/butterfly-3000.jpg

it'll return something like this:

Hashed request: TGQ1WWRKVGUrZUpoNmJMc2RMUENPL2t6ZDJkWkdOejlkM0p0U0F3WTgxOU5IMzF3U3R0d2V4b3dqbG52cFRTSFZDcmhrY1JnaGZYOHJ3V0NpZDNNRmc9PQ==

Now you can request the image throw this new url:

http://localhost:8080/upload/TGQ1WWRKVGUrZUpoNmJMc2RMUENPL2t6ZDJkWkdOejlkM0p0U0F3WTgxOU5IMzF3U3R0d2V4b3dqbG52cFRTSFZDcmhrY1JnaGZYOHJ3V0NpZDNNRmc9PQ==