Sandstorm personal cloud platform

Containerization is popular these days, with technologies like Docker having made a big splash recently. But earlier containerization efforts like LXC (which Docker was at one time based on) and OpenVZ laid the foundation, and newer efforts like Sandstorm may take the technique even further. Sandstorm is an early-stage project that bills itself as a "personal cloud platform". It is targeted at solving some of the same kinds of problems that FreedomBox is trying to solve, such as allowing users to take control of their own data.

Containers are not really Linux distributions per se, but they solve some of the same problems, particularly in the area of packaging. Both Docker and Sandstorm provide a mechanism to distribute Linux applications that is quite different from what users of traditional distributions have become accustomed to. Each Sandstorm container is, in some sense, a mini-distribution focused on providing just the environment needed by a particular application. All of the binaries, libraries, configuration, and so on, are collected up into the container so that they are available to a particular application instantiation, but not to other applications.

That isolation is why lead developer Kenton Varda (who developed the open source version of Protocol Buffers while at Google) calls the containers "sandboxes". The idea is to isolate each application instance in its sandbox so that it cannot affect any of the other applications running in sandboxes on the same host. There is still a fair way to go before that goal is realized. As the Caveats section on the Sandstorm GitHub page indicates: "At present, Sandstorm's sandboxing is incomplete. Malicious code probably can escape. Malicious code definitely can DoS your server by consuming all available resources."

For applications to work in this new, sandboxed world, they will need to be packaged up differently, using the Sandstorm tools. The porting guide shows how to use those tools. The basic mechanism is to install the application on a development server, which will observe an application in action while recording all of the files that it uses during its execution. That list of files, potentially with tweaks made by the developer, can then be used to create a container that will run the application when it gets installed on a Sandstorm server.

The vision is to have these applications available in an "App Store" of sorts, where the applications can be easily installed by users onto their own Sandstorm server (or as instances under their control on a shared Sandstorm server). There would be no command-line interaction required, as "the only way you ever interact with an app is through your web browser", Varda said in the Sandstorm Development Google Group. He was answering a question about the differences between Sandstorm and Docker, and continued:

The project is quite new, as it was announced by Varda on March 24. The plan is for Sandstorm to use Varda's follow-up to Protocol Buffers, called Cap'n Proto, for remote procedure calls (RPCs) between the sandboxed applications. The permissions for doing so would be managed through a powerbox-like graphical user interface (GUI). Currently, Sandstorm's API only allows sandboxed applications to handle HTTP and WebSocket requests, but much more is planned.

The big picture is all about users taking control of their own data, so that it can't be misappropriated, spied upon, data mined, or simply vanish if the service where it is stored decides to close up shop. There's a lot to do to get there. Even with a platform that handles problems like security and authentication, as Sandstorm is envisioned to do, there will need to be a large number of cooperating applications to make for a viable ecosystem. The current crop of Sandstorm apps is small, with just a handful of simple apps that can be installed either on local Sandstorm servers or on the managed instances that those who have signed up and been invited to join the Alpha test can use.

Overall, Sandstorm is an interesting idea of what user-controlled services could look like down the road. It remains to be seen if enough users actually care about that control and are willing to do something about it. The promise of total app isolation, such that malicious apps can do no real damage, is intriguing, as is having a user-friendly way to set it all up and get it running. There's a lot of promise, but it may be difficult to nurture a robust, cooperating app ecosystem, which could make for a fairly large hurdle for the project. In any case, it is an ambitious vision and it will be interesting to watch where Sandstorm goes from here.

[ Thanks to Jim Garrison, who reminded us about a topic that has been on our list for a while now. ]