Charliecloud vs gVisor

Charliecloud is free, open-source container software for high-performance computing on Linux. It runs containers without privileged operations or daemons by using Linux user namespaces, with minimal configuration changes on computing-center resources. Users can build images, push and pull them to registries, and use accelerators such as GPUs. Its layer-free build cache is based on Git rather than union-mount filesystems and tarballs, and Dockerfiles are parsed with a formal grammar. The ch-image tool supports registry authentication and registries including GitLab Container Registry. At runtime, ch-run can inject host resources through the Container Device Interface, including NVIDIA GPUs and Cray networking. Installation is available from a release tarball, Git checkout, Spack, or Fedora/EPEL. Charliecloud requires Linux user namespaces and has been run on x86-64, ARM, and Power; current testing covers x86_64 and ARM. It is distributed under Apache License, Version 2.0. The project supports only the current release and provides no internal security boundary.

gVisor is a free, open-source Linux-compatible sandbox and application kernel for running containers while isolating the host from untrusted code. It is intended for workloads such as user-uploaded, LLM-generated, and third-party code. Instead of passing sandboxed applications’ system calls directly to the host, its Sentry handles them; a Gofer process mediates filesystem access. The project describes a least-privilege design with a restrictive system call filter. It documents use with Docker, Kubernetes, containerd, and OCI runtimes, including Kubernetes configurations using GKE Sandbox, Minikube, or containerd with the gVisor shim. gVisor can stream application trace points to an external threat detection engine such as Falco, and can checkpoint and restore containers. Most CUDA applications can run unmodified in the sandbox with selected NVIDIA driver versions, but GPU support is restricted to certain models, drivers, capabilities, device files, ioctl calls, and platforms. Installation requires Linux 5.6 or later on x86_64 or ARM64. Compatibility is best-effort, and some applications may not work because not every system call, /proc file, or /sys file is implemented. Hardware side-channel protection is generally not provided.