What is Cuber used for?

Cuber is an Apache-licensed Ruby CLI that packages apps with buildpacks and deploys them to any Kubernetes cluster from a short Cuberfile. It is a good fit for teams leaving Heroku for cheaper infrastructure and deploying apps to a self-managed Kubernetes cluster.

Is Cuber open source?

Yes. Cuber is open source under the Apache-2.0 licence. Its source code is on GitHub at cuber-cloud/cuber-gem and is written mainly in Ruby.

Yes. Cuber is open source, so the software itself is free to use.

What is Cuber an alternative to?

Cuber is an open-source alternative to Heroku and Scalingo. Other open-source alternatives to Heroku include Kubero, Dokku and Tsuru.

Is Cuber actively maintained?

The most recent commit to Cuber was on 12 April 2026, and the latest release is v1.14.0, published on 12 April 2026. The project has 712 stars on GitHub.

Cuber: open-source alternative to Heroku, Scalingo

About Cuber

Cuber is an automation tool, written in Ruby, that builds and deploys applications written in any language or framework onto Kubernetes. It targets teams that want the cost control and cloud choice of running on bare Kubernetes but would rather not manage the many manifests and configuration steps involved, offering a workflow closer to a PaaS.

Deployment is driven by a short configuration file called a Cuberfile and a single cuber deploy command that packages the app and rolls it out to a cluster. A CLI also lets you monitor application status. The README positions Kubernetes as a cheaper, lock-in-free option compared with a managed PaaS such as Heroku, and says the tool grew out of several years of production use at Pushpad.

Cuber is released under Apache-2.0 and runs from your own machine or CI, requiring Ruby, git, Docker, the pack buildpack CLI and kubectl. It is a self-managed tool rather than a hosted service: you bring your own Kubernetes cluster from whichever cloud provider you choose.

Key features

Single Cuberfile configuration for each app
One-command deploy to any Kubernetes cluster
Buildpack-based packaging for any language
Status monitoring through CLI commands
Works across different cloud providers

Good fit for

→Teams leaving Heroku for cheaper infrastructure
→Deploying apps to a self-managed Kubernetes cluster

Built with: Ruby; Kubernetes; Docker
Tags: kubernetes; deployment; paas; devops; buildpacks; ruby; docker; continuous-delivery

Cuber: questions and answers

What is Cuber used for?: Cuber is an Apache-licensed Ruby CLI that packages apps with buildpacks and deploys them to any Kubernetes cluster from a short Cuberfile. It is a good fit for teams leaving Heroku for cheaper infrastructure and deploying apps to a self-managed Kubernetes cluster.
Is Cuber open source?: Yes. Cuber is open source under the Apache-2.0 licence. Its source code is on GitHub at cuber-cloud/cuber-gem and is written mainly in Ruby.
Is Cuber free?: Yes. Cuber is open source, so the software itself is free to use.
What is Cuber an alternative to?: Cuber is an open-source alternative to Heroku and Scalingo. Other open-source alternatives to Heroku include Kubero, Dokku and Tsuru.
Is Cuber actively maintained?: The most recent commit to Cuber was on 12 April 2026, and the latest release is v1.14.0, published on 12 April 2026. The project has 712 stars on GitHub.