callisto instructions

callisto.liw.fi is a Radicle CI instance that runs CI using Ambient for open source Rust projects, for free. That means your project should have a Radicle repository, but it’s OK for it to be a mirror where you push when you want CI to run on callisto. Your projects also needs to be set up to use Ambient.

Radicle is an open source, peer-to-peer code collaboration stack built on Git.

Ambient is a CI engine that runs any code from the project under test in a virtual machine without network access. It has been developed to make it safe and secure to run CI for other people’s code.

Radicle

A very terse summary of how to start using Radicle:

• Download a release binary from https://radicle.xyz/download, there’s ones for Linux and macOS.
• Run rad auth to initialize a Radicle node on your machine.
• Switch to your project Git checkout.
• Run rad init to create a Radicle repository out of the Git repository. This will not affect how you use Git in the future, but there will be a new rqd remote.
• To push changes to your Radicle node, so they get synced with other nodes, run git push rad HEAD in your Git repository. You need to do this so the changes reach callisto eventually and it can run CI on them.

Project set up for Ambient

To use https://callisto.liw.fi/:

• Your project must be using Rust.

• CI will run in Ambient, which runs actions in a virtual machine that has no network access.

• Create a file .radicle/ambient.yaml at the root of your repository with content like the following:

  pre_plan:
    - action: cargo_fetch
  plan:
    - action: cargo_fmt
    - action: cargo_clippy
    - action: cargo_test

• Here, pre_plan is a list of actions to run on the host, before the virtual machine runs. The only action you can put there is cargo_fetch, which downloads Rust crates and makes them available in the VM.

• The actions in plan are executed in the VM. The VM isolates them so that the actions can’t do any damage apart from spending time.

• Available actions:

  • cargo_build, cargo_clippy, cargo_fmt, cargo_test - run the corresponding cargo command
  • custom - run named executable located in .ambient in the repository, with the arguments serialized as JSON in stdin; in the example above, .ambient/dch
  • deb - build a deb package
  • shell - run arbitrary shell snippet with Bash

• Ambient also supports post_plan actions, but they aren’t enabled on callisto

• There is a limit on CPUs, RAM, and run time, and disk space used for cache (/workspace/cache in the VM), dependencies (/workspace/deps), and artifacts (/workspace/artifacts), and the run will fail end (possibly with mysterious error messages) if those limits are exceeded.