What is Charliecloud?

Charliecloud provides user-defined software stacks (UDSS) for high-performance computing (HPC) centers. This “bring your own software stack” functionality addresses needs such as:

  • software dependencies that are numerous, complex, unusual, differently configured, or simply newer/older than what the center provides;
  • build-time requirements unavailable within the center, such as relatively unfettered internet access;
  • validated software stacks and configuration to meet the standards of a particular field of inquiry;
  • portability of environments between resources, including workstations and other test and development system not managed by the center;
  • consistent environments, even archivally so, that can be easily, reliabily, and verifiably reproduced in the future; and/or
  • usability and comprehensibility.

WARNING: Cray CLE in recent versions has a bug that crashes nodes when cleaning up after some jobs, including if Charliecloud has been used. See the installation instructions for a workaround.

How does it work?

Charliecloud uses Linux user namespaces to run containers with no privileged operations or daemons and minimal configuration changes on center resources. This simple approach avoids most security risks while maintaining access to the performance and functionality already on offer.

Container images can be built using Docker or anything else that can generate a standard Linux filesystem tree.

How do I learn more?

Who is responsible?

The core Charliecloud team at Los Alamos is:

Patches (code, documentation, etc.) contributed by:

How can I participate?

Questions, comments, feature requests, bug reports, etc. can be directed to:

Patches are much appreciated on the software itself as well as documentation. Optionally, please include in your first patch a credit for yourself in the list above.

We are friendly and welcoming of diversity on all dimensions.