rs-cdn

rs-cdn is a CDN written in Rust for Harmony.

Resources on rs-cdn follow this structured path in the file system: /{category}/{identifier}/{sha1hash}.png

• category: Denotes the group to which the resource belongs, such as avatars.
• identifier: Unique ID corresponding to the resource. For avatars, this is the user id.
• sha1hash: The SHA1 hash of the image file.

Each identifier directory is intended to be exclusive, hosting a single resource at any given time. Resources can be found inside ./uploads during development.

Running the Service

Prerequisites

• Docker Engine

• Compose V2

• Cross-rs

Building

Before you can start the application, you need to build it first.

You can run make build to create a debug build, and make release to create a release build.

Starting the Server

We use Compose v2 for this project. As such, we use docker compose instead of docker-compose.

Debug mode:

To start the application in development mode, run make build && docker compose up.

Release mode:

You can also run in release mode, using make release && docker compose -f compose.yaml -f compose.release.yaml up.

This will give you a more realistic experience in regards to speed of image processing, as debug mode is significantly slower for large files (> 1s in debug, vs < 50ms in release).

Authentication

Publishers are authenticated through a digital signature accompanying each upload. This signature attests to the legitimacy of the content being uploaded.

To generate a signature for development, use the provided script:

./create_signature.sh <path_to_image>

Incorporate the output directly into the signature field when making a POST request.

Uploading Resources

Uploading a new resource requires a valid signature as outlined in the Authentication section.

Example POST Request:

curl -X POST http://localhost:8080/avatars/1234567890 \
 -H 'Content-Type: multipart/form-data' \
 -F "image=@assets/orange.jpg" \
 -F "signature=$(./create_signature.sh assets/orange.jpg)"

Accessing Resources

After a successful upload, the resource is accessible through a URL structured as follows:

http://localhost:8080/{category}/{id}/{sha1hash}.png

Example:

For the uploaded orange.jpg image with the identifier 1234567890:

http://localhost:8080/avatars/1234567890/b4d3499823b249df78507443a2fa6ec90933e3c4.png

Navigating to the above link in a web browser will display the uploaded image.