Provided by: charliecloud-common_0.38-2_all 
NAME
charliecloud - Lightweight user-defined software stacks for high-performance computing
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, reliably, and
verifiably reproduced in the future; and/or
• usability and comprehensibility.
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?
• Documentation: https://hpc.github.io/charliecloud
• GitHub repository: https://github.com/hpc/charliecloud
• Low-traffic mailing list for announcements: https://groups.io/g/charliecloud
• We wrote an article for USENIX’s magazine ;login: that explains in more detail the
motivation for Charliecloud and the technology upon which it is based: ‐
https://www.usenix.org/publications/login/fall2017/priedhorsky
• For technical papers about Charliecloud, refer to the Technical publications section
below.
WHO IS RESPONSIBLE?
Contributors:
• Richard Berger <rberger@lanl.gov>
• Lucas Caudill <lcaudill@lanl.gov>
• Rusty Davis <rustyd@lanl.gov>
• Hunter Easterday <heasterday@lanl.gov>
• Oliver Freyermuth <o.freyermuth@googlemail.com>
• Shane Goff <rgoff@lanl.gov>
• Michael Jennings <mej@lanl.gov>
• Christoph Junghans <junghans@lanl.gov>
• Dave Love <dave.love@manchester.ac.uk>
• Jordan Ogas <jogas@lanl.gov>
• Kevin Pelzel <kpelzel@lanl.gov>
• Megan Phinney <mphinney@lanl.gov>
• Reid Priedhorsky <reidpr@lanl.gov>, co-founder and project lead
• Tim Randles <trandles@lanl.gov>, co-founder
• Benjamin “The Storm” Stormer <bstormer@lanl.gov>
• Meisam Tabriz <meisam.tabriz@mpcdf.mpg.de>
• Matthew Vernon <mv3@sanger.ac.uk>
• Peter Wienemann <wienemann@physik.uni-bonn.de>
• Lowell Wofford <lowell@lanl.gov>
HOW CAN I PARTICIPATE?
Use our GitHub page: https://github.com/hpc/charliecloud
Bug reports and feature requests should be filed as “Issues”. Questions, comments, support
requests, and everything else should use our “Discussions”. Don’t worry if you put
something in the wrong place; we’ll be more than happy to help regardless.
We also have a mailing list for announcements: https://groups.io/g/charliecloud
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.
TECHNICAL PUBLICATIONS
If Charliecloud helped your research, or it was useful to you in any other context where
bibliographic citations are appropriate, please cite the following open-access paper:
Reid Priedhorsky and Tim Randles. “Charliecloud: Unprivileged containers for
user-defined software stacks in HPC”, 2017. In Proc. Supercomputing. DOI: ‐
10.1145/3126908.3126925.
Note: This paper contains out-of-date number for the size of Charliecloud’s code. Please
instead use the current number in the FAQ.
Other publications:
• We compare the performance of three HPC-specific container technologies against bare
metal, finding no concerns about performance degradation.
Alfred Torrez, Tim Randles, and Reid Priedhorsky. “HPC container runtimes have
minimal or no performance impact”, 2019. In Proc. CANOPIE HPC Workshop @ SC. DOI: ‐
10.1109/CANOPIE-HPC49598.2019.00010.
• A demonstration of how low-privilege containers solve increasing demand for software
flexibility.
Reid Priedhorsky, R. Shane Canon, Timothy Randles, and Andrew J. Younge. “Minimizing
privilege for building HPC containers”, 2021. In Proc. Supercomputing. DOI: ‐
10.6084/m9.figshare.14396099.
• Charliecloud’s build cache performs competitively with the standard many-layered union
filesystem approach and has structural advantages including a better diff format, lower
cache overhead, and better file de-duplication.
Reid Priedhorsky, Jordan Ogas, Claude H. (Rusty) Davis IV, Z. Noah Hounshel, Ashlyn
Lee, Benjamin Stormer, and R. Shane Goff. “Charliecloud’s layer-free, Git-based
container build cache”, 2023. In Proc. Supercomputing. DOI: 10.1145/3624062.3624585.
COPYRIGHT AND LICENSE
Charliecloud is copyright © 2014–2023 Triad National Security, LLC and others.
This software was produced under U.S. Government contract 89233218CNA000001 for Los Alamos
National Laboratory (LANL), which is operated by Triad National Security, LLC for the U.S.
Department of Energy/National Nuclear Security Administration.
This is open source software (LA-CC 14-096); you can redistribute it and/or modify it
under the terms of the Apache License, Version 2.0. A copy is included in file LICENSE.
You may not use this software except in compliance with the license.
The Government is granted for itself and others acting on its behalf a nonexclusive,
paid-up, irrevocable worldwide license in this material to reproduce, prepare derivative
works, distribute copies to the public, perform publicly and display publicly, and to
permit others to do so.
Neither the government nor Triad National Security, LLC makes any warranty, express or
implied, or assumes any liability for use of this software.
If software is modified to produce derivative works, such derivative works should be
clearly marked, so as not to confuse it with the version available from LANL.
Reporting bugs
If Charliecloud was obtained from your Linux distribution, use your distribution’s bug
reporting procedures.
Otherwise, report bugs to: https://github.com/hpc/charliecloud/issues
SEE ALSO
ch-checkns(1), ch-completion.bash(7), ch-convert(1), ch-fromhost(1), ch-image(1),
ch-run(1), ch-run-oci(1), ch-test(1),
Full documentation at: https://hpc.github.io/charliecloud
NOTE
These man pages are for Charliecloud version 0.38 (Git commit 0.38).
COPYRIGHT
2014–2023, Triad National Security, LLC and others