rules_version = '2';

service firebase.storage {
  match /b/{bucket}/o {
    match /messages/{fileName} {

      // anyone can view uploaded images
      allow read: if true;

      // anyone can upload an image attached to a message
      // must be an image under 5MB
      allow create: if
        request.resource.size < 5 * 1024 * 1024 &&
        request.resource.contentType.matches('image/.*');

      // no edits or deletes through the client
      allow update, delete: if false;
    }
  }
}