/colima

Container runtimes on MacOS with minimal setup

Primary LanguageGoMIT LicenseMIT

Colima

Go

Container runtimes on macOS with minimal setup.

Demonstration

Features

  • Intel and M1 Macs support
  • Simple CLI interface
  • Docker and Containerd support
  • Port Forwarding
  • Volume mounts
  • Kubernetes

Getting Started

Installation

Colima is available on Homebrew. Check here for other installation options.

brew install colima

Or stay on the bleeding edge

brew install --HEAD colima

Usage

Start Colima with defaults

colima start

For more usage options

colima --help
colima start --help

Runtimes

On initial startup, Colima initiates with a user specified runtime that defaults to Docker.

Docker

Docker client is required for Docker runtime. Installable with brew brew install docker.

You can use the docker client on macOS after colima start with no additional setup.

Containerd

colima start --runtime containerd starts and setup Containerd. You can use colima nerdctl to interact with Containerd using nerdctl.

It is recommended to run colima nerdctl install to install nerdctl alias script in $PATH.

Kubernetes

kubectl is required for Kubernetes. Installable with brew install kubectl.

To enable Kubernetes, start Colima with --with-kubernetes flag.

colima start --with-kubernetes

Interacting with Image Registry

For Docker runtime, images built or pulled with Docker are accessible to Kubernetes.

For Containerd runtime, images built or pulled in the k8s.io namespace are accessible to Kubernetes.

Customizing the VM

The default VM created by Colima has 2 CPUs, 2GiB memory and 60GiB storage.

The VM can be customized by passing --cpu, --memory and --disk to colima start. If VM is already created, stop the VM and apply the flags when starting it.

NOTE that only cpu and memory can be changed at anytime. Disk size cannot be changed after the VM is created.

Customization Examples

  • create VM with 1CPU, 2GiB memory and 10GiB storage.

    colima start --cpu 1 --memory 2 --disk 10
    
  • modify an existing VM to 4CPUs and 8GiB memory.

    colima stop
    colima start --cpu 4 --memory 8
    

Project Goal

To provide container runtimes on macOS with minimal setup.

Project Status

⚠️ The project is still in active early stage development and updates may introduce breaking changes.

What is with the name?

Colima means Containers in Lima.

Since Lima is aka Linux on Mac. By transitivity, Colima can also mean Containers on Linux on Mac.

FAQ

Can it run alongside Docker for Mac?

No, except when started with Containerd runtime. Colima assumes to be the default Docker context and will conflict with Docker for Mac. You should run either, not both.

Yes, from version v0.3.0, Colima can run alongside Docker for Mac.

How to enable writable volumes?

By default, Colima mounts the host's $HOME directory as readonly in the VM. Volume mounts and Compose should work as expected but only readonly.

Colima uses Lima for the VM and Lima's support for writable volumes is still experimental. It is recommended to only mount the necessary directories as writable rather than the entire $HOME directory.

The following mounts $HOME/projects and $HOME/work directories as writable.

colima start --mount $HOME/projects:w --mount $HOME/work:w

How to customize Docker config e.g. add insecure registries?

On first startup, Colima generates Docker daemon.json file at $HOME/.colima/docker/daemon.json.

Simply modify the daemon.json file accordingly and restart Colima.

How does it compare to minikube, Kind, K3d?

For Kubernetes

Yes, you can create a Kubernetes cluster with minikube (with Docker driver), Kind or K3d instead of enabling Kubernetes in Colima. Those are better options if you need multiple clusters, or do not need Docker and Kubernetes to share the same images and runtime.

For Docker

Minikube with Docker runtime can expose the cluster's Docker with minikube docker-env. But there are some caveats.

  • Kubernetes is not optional, even if you only need Docker.

  • All of minikube's free drivers for macOS fall-short in one of performance, port forwarding or volumes. While port-forwarding and volumes are non-issue for Kubernetes, they can be a deal breaker for Docker-only use.

Are M1 macs supported?

Colima supports and works on M1 macs but not rigorously tested as the author do not currently possess an M1 device. Feedbacks would be appreciated.

Help Wanted

  • Homebrew formula
  • Testing on M1 Macs

License

MIT