Security in Apptainer
First please see the Security section of the user guide.
Configuration & Runtime Options
System administrators who manage Apptainer can use configuration files to set security restrictions, grant or revoke a user’s capabilities, manage resources and authorize containers etc.
For example, the Execution Control List file allows restricting usage of SIF containers based on their signature and the key used to sign them.
Configuration files and their parameters are documented for administrators here.
When running a container as root, Apptainer can apply hardening rules using seccomp and apparmor. Please see the Security Options section of the user guide.
Limits on resource usage by containers can be enforced using cgroups. On systems that use cgroups v1, only the root user can set resource limits. On systems that use cgroups v2 and systemd, all users can apply resource limits as long as the system is configured for delegation.
By default, EL9, Ubuntu 22.04, Debian 11, Fedora 31 and newer use cgroups v2 and
are configured for delegation so that unprivileged users will be able to use the
--apply-cgroups and other resource limit flags of Apptainer without
On EL8 and Ubuntu 20.04 it is possible to setup a compatible configuration by following the ‘Enabling cgroup v2’ and ‘Enabling CPU, CPUSET, and I/O delegation’ steps at the rootless containers website.
See the Limiting Container Resources section of the user guide for more details of how to apply cgroups limits to containers at runtime.