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SSH over gRPC or how Orchard simplifies accessing VMs in private networks

We started developing Orchard, an orchestrator for Tart, with the requirement that it should allow users to access virtual machines running on worker nodes in private networks that users might not have access to.

At the same time, we wanted to enable users to access VMs on these remote workers just as easily as they’d access network services on their local Tart VMs.

While these features sound great on paper, they pose a technical problem: how do we connect to the remote workers, let alone VMs running on these workers, if we can’t assume that these workers will be easily reachable? And how do we establish an SSH connection with a VM running on a remote worker through all these hoops?

Announcing Orchard orchestration for managing macOS virtual machines at scale

Today we are happy to announce general availability of Orchard – our new orchestrator to manage Tart virtual machines at scale. In this post we’ll cover the motivation behind creating yet another orchestrator and why we didn’t go with Kubernetes or Nomad integration.

What problem are we trying to solve?

After releasing Tart we pretty quickly started getting requests about managing macOS virtual machines on a cluster of Apple Silicon machines rather than just a single host which only allows a maximum of two virtual machines at a time. By the end of 2022 the requests reached a tipping point, and we started planning.

Changing Tart License

TLDR: We are transitioning Tart's licensing from AGPL-3.0 to Fair Source 100. This change will permit unlimited installations on personal computers, but organizations that exceed a certain number of server installations utilizing 100 CPU cores will be required to obtain a paid license.

Background

Exactly a year ago on February 11th 2022 we started working on Tart – a tiny CLI to run macOS virtual machines on Apple Silicon. Three months later we successfully started using Tart in our own production system and decided to share Tart with everyone.

The goal was to establish a community of users and contributors to transform Tart from a small CLI to a robust tool for various scenarios. Unfortunately, we were not successful in attracting a significant number of contributors. It's important to note that we did have seven individuals who contributed to the development of Tart to the best of their abilities. However, one of the challenges of contributing to Tart is that the skill set required for a contribution is vastly different from the skill set typically possessed by regular Tart users in their daily work. Specifically, a contributor needs to have knowledge of the Swift programming language, as well as a background in operating systems and network stack. This is the reason why 98.8% of the code and all the major features were contributed by Cirrus Labs engineers.