🍪 anocir

[an-oh-cheer] Another OCI Runtime.

An experimental Linux container runtime, implementing the OCI Runtime Spec.

Note

This is a personal project to explore how container runtimes work. It's not production-ready. If you're looking for a production-ready alternative to runc, I think youki is pretty cool.

The process of building this is being documented in a series of blog posts which you can read here: Building a container runtime from scratch in Go.

🗺️ Roadmap

• Implement the OCI Runtime Spec and pass all tests in the OCI Runtime Spec test suite.
• Implement the containerd shim API.
• Implement the Kubernetes CRI API and pass all tests in the CRI validation test suite.

🚀 Quick start

1. Download the tarball for your architecture from Releases.
2. Extract the anocir binary from the tarball into somewhere in $PATH, e.g. ~/.local/bin.
3. View docs by running anocir --help or anocir COMMAND --help.

👩‍💻 Usage

Caution

Some features may require sudo and make changes to your system. Take appropriate precautions.

Docker

By default, the Docker daemon uses the runc container runtime. anocir can be used as a drop-in replacement for runc.

You can find detailed instructions on how to configure alternative runtimes in the Docker docs. If you just want to quickly experiment, the following should suffice:

# 1. Stop any running Docker service
sudo systemctl stop docker.service

# 2. Start the Docker Daemon with added anocir runtime
sudo dockerd --add-runtime anocir=PATH_TO_ANOCIR_BINARY

# 3. Run a container using the anocir runtime
docker run -it --runtime anocir busybox sh

CLI

The anocir CLI implements the OCI Runtime Command Line Interface spec. You can view the docs by running anocir --help or anocir [COMMAND] --help.

⚒️ Contributing

Feel free to leave any comments/suggestions/feedback in issues.

Build from source

Prerequisite: Compiler for Go installed (instructions).

1. git clone git@github.com:nixpig/anocir.git
2. cd anocir
3. make build
4. mv tmp/bin/anocir ~/.local/bin

I'm developing anocir on the following environment. Even with the same set up, YMMV.

• Linux vagrant 6.8.0-31-generic #31-Ubuntu SMP PREEMPT_DYNAMIC Sat Apr 20 00:40:06 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
• go version go1.25.5 linux/amd64
• Docker version 27.3.1, build ce12230

You can spin up this VM from the included Vagrantfile, just run vagrant up.

Run the OCI test suite

See OCI.md for details of tests.

1. Start the dev VM:

   vagrant up --provision && vagrant ssh
   

2. Build the anocir binary:

   cd /anocir && make build-oci

3. Build the test executables:

   cd /anocir/test/runtime-tools && make runtimetest validation-executables

4. Run the test suite:

   sudo RUNTIME=/anocir/tmp/bin/anocir /anocir/test/scripts/oci-integration.sh

💡 Inspiration

While this project was built entirely from scratch, inspiration was taken from existing runtimes, in no particular order:

• youki (Rust)
• pura (Rust)
• runc (Go)
• crun (C)

📃 License

MIT