This is a free open source AGPL licensed slightly modified version of cocalc-docker, but for running CoCalc on a Kubernetes cluster. There is one pod for the server and one pod for each project.
-
As of Dec 2020, we have decided that CoCalc-Kubernetes will not be supported further until there is at least one paying customer. We are a small company, and must choose very carefully how we spend our time. So far nobody has purchased Cocalc-Kubernetes, wheeas many people have purchased cocalc-docker licenses, so that's where our effort is going.
-
I've last updated the images on DockerHub that this uses to the latest version of CoCalc as of May 12, 2020.
See server/README.md to get going!
- Much of this code is licensed under the AGPL. If you would instead like a business-friendly MIT license, please contact help@cocalc.com, and we will sell you a 1-year license for $1499. This also includes some support, though with no guarantees (that costs more).
- Join the CoCalc Docker mailing list for news, updates and more.
- Use the CoCalc mailing list for general community support.
- If you setup everything as explained in server/README.md, including appropriate network restrictions on the project pods, then there are no known security vulnerabilities. In particular, this is much safer to run than cocalc-docker, if you are going to expose this to untrusted (or uncareful) users.
cocalc-kubernetes is an open version of CoCalc that can be run on an existing generic Kubernetes cluster.
It is as similar as possible to cocalc-docker, with the following changes:
- It runs in a Kubernetes cluster rather than a plain Docker install, and
- Projects run as separate pods on the cluster rather than all in the same Docker container.
The benefits of this architecture include:
- Projects can have individual resource limitations imposed by Kubernetes.
- The security issues with cocalc-docker (involving projects connecting to other project services on localhost) can be addressed by blocking outgoing network connections from projects.
- Projects run across a cluster, so the number of projects that one can run at once is a function of the number (and size) of nodes in the cluster, rather than cocalc-docker host.
- This can be done with just a slight modification and addition to the entirely open source (AGPL) codebase that cocalc-docker uses.
The drawbacks of this architecture over a more complicated architecture like the closed-source KuCalc (what https://cocalc.com uses) include:
- It is unclear to what extent it can handle a large number of simultaneous users, since the entire server component (the database, hub, NFS file server, etc.) are all served from a single pod.
- Project storage is just a single NFS server, so disk iops may be lower for client projects, which may or may not be an issue depending on the network and use of projects.
- Filesystem level snapshots and other backups have to be handled outside CoCalc. This is the responsibility of the admin and is not part of cocalc-kubernetes at present. However, the TimeTravel functionality, which records every version of a file or notebook while you work on it, and lets you browse all past versions, does fully work in cocalc-kubernetes.
- The project image is much more minimal than the one provided by https://cocalc.com -- it has to be small enough to reasonably run in a normal way without pull taking too long. The image in KuCalc is hundreds of gigabytes but mounts quickly using some sophisticated tricks.