As announced, dotCloud Sandbox is an open-source project which tries to replicate the sandbox flavor of dotCloud: a free and easy way to build web applications.

Sandbox takes your application and its dotcloud.yml as input and outputs a Docker image for each service that can be built; it doesn't support databases (yet?).

Sandbox tries to mimic the original dotCloud build process but a few differences exist:

• database credentials won't be generated in environment.json;
• postinstall is not executed (databases are supposed to be available when it's run), but you can probably use a post-build hook instead.

• Docker ≥ 0.2.0, ≤ 0.3.2 or Docker ≥ 0.4.1;
• Python 2.7 (older versions won't work);
• A C compiler and the Python development headers.

The full documentation is reachable at http://sandbox.dotcloud.com/.