User Story
As a DIRAC site administrator deploying ARM (aarch64) and other non-x86_64 worker nodes, I want DIRAC to automatically resolve the correct container image for the worker node's architecture, so that Pilot-Jobs can seamlessly execute payloads on heterogeneous clusters without manual per-architecture configuration.
Feature Description
DIRAC currently hardcodes or configures a single container image path (via ContainerRoot) that implicitly assumes x86_64. With the introduction of ARM resources and the CVMFS unpacked.cern.ch support for multi-architecture images, DIRAC needs to:
- Detect the worker node architecture at runtime (using platform.machine() / uname -m).
- Map it to the OCI architecture name used by the CVMFS multiarch layout (e.g.
x86_64: amd64, aarch64: arm64).
- Resolve the correct image path under the CVMFS .multiarch directory structure:
/cvmfs/unpacked.cern.ch/.multiarch/<arch>/<registry>/<image>:<tag>
For example: /cvmfs/unpacked.cern.ch/.multiarch/arm64/registry.hub.docker.com/library/alma9:latest
Note: Variant handling is deferred. Initially, DIRAC only resolves by architecture (uname -m), not by variant. Can be added later if needed.
It should affect both code paths that launch containers:
SingularityComputingElement (job execution via the JobAgent`)dirac-apptainer-exec (Pilot-Job command execution)
It should maintain backward compatibility with the existing ContainerRoot configuration option: if ContainerRoot is set and the new multiarch path doesn't exist, fall back to ContainerRoot.
Definition of Done
Alternatives Considered
No response
Related Issues
First attempt (CVMFS unpacked support for multi-architecture did not exist at that time, we are in the process of testing it with LHCb images): #7589
Additional Context
No response
User Story
As a DIRAC site administrator deploying ARM (aarch64) and other non-x86_64 worker nodes, I want DIRAC to automatically resolve the correct container image for the worker node's architecture, so that Pilot-Jobs can seamlessly execute payloads on heterogeneous clusters without manual per-architecture configuration.
Feature Description
DIRAC currently hardcodes or configures a single container image path (via
ContainerRoot) that implicitly assumesx86_64. With the introduction of ARM resources and the CVMFSunpacked.cern.chsupport for multi-architecture images, DIRAC needs to:x86_64:amd64,aarch64:arm64)./cvmfs/unpacked.cern.ch/.multiarch/<arch>/<registry>/<image>:<tag>For example:
/cvmfs/unpacked.cern.ch/.multiarch/arm64/registry.hub.docker.com/library/alma9:latestNote: Variant handling is deferred. Initially, DIRAC only resolves by architecture (uname -m), not by variant. Can be added later if needed.
It should affect both code paths that launch containers:
SingularityComputingElement (job execution via theJobAgent`)dirac-apptainer-exec(Pilot-Job command execution)It should maintain backward compatibility with the existing
ContainerRootconfiguration option: ifContainerRootis set and the new multiarch path doesn't exist, fall back toContainerRoot.Definition of Done
Alternatives Considered
No response
Related Issues
First attempt (CVMFS
unpackedsupport for multi-architecture did not exist at that time, we are in the process of testing it with LHCb images): #7589Additional Context
No response