A Simple File Cache Server For The Firebase Cloud Storage

Caches files and scales images from the Firebase Cloud Storage. This project aims to reduce the traffic of the Firebase Cloud Storage, which is limited to 1GB per day for free, thus cutting costs.

Installation

• Copy the docker-compose.yml file into your local directory.
• Run docker compose up -d --build to start the container.
• The server should now run on 0.0.0.0:9998 (you can change the port in the docker-compose.yml file)

Update

• Run docker compose down to stop the running container
• Rebuild and start the container with docker compose up -d --build

How To Use

Cache any asset

Instead of using https://firebasestorage.googleapis.com/v0/b/<PROJECT>/o/..., make the request to https://<YOUR-ENDPOINT>/ and provide the query-parameter url.

e.g.: https://<YOUR-ENDPOINT>/?url=https://firebasestorage.googleapis.com/v0/b/<PROJECT>/o/...

Note, that the access rights to the assets will be preserved. The token passed with the url will be validated by firebase, even when the file is cached on the server.

Scale images

To scale an image from the cloud storage, use the /scale/<size> endpoint. size can be <max-width>x<max-height> or <max-height / max-width> (single parameter). Note, that the aspect ratio of the image will be preserved. The image will be cached as seen above and gets downscaled on the fly. If the requested url does not lead to an image file, the original asset will be returned.

e.g.:

• /scale/500x700?url=https://firebasestorage... Scales the image to 500 x 700 while keeping the aspect ratio.
• /scale/300?url=https://firebasestorage... Scales the image to 300 x 300

Cache location

By default, all assets will be cache on the host machine in the ./cache folder relative to docker-compose.yml file. This can be changed by modifying the docker-compose.yml file.