Pro overlays

Warewulf Pro ships five configuration overlays that plug into Warewulf to configure common cluster components without modifying the underlying node image. Each overlay is packaged as a separate warewulf-overlays-<name> RPM.

For general overlay concepts - what overlays are, how they're applied at boot and runtime, how to write your own - see the upstream overlays documentation.

Installation

Install all Pro overlays at once:

# depot enable warewulf-pro
# dnf -y install "warewulf-overlays-*"

Or install individually:

# dnf -y install warewulf-overlays-apptainer warewulf-overlays-chrony

The overlays

apptainer

Configures subuid and subgid on cluster nodes based on the corresponding files on the Warewulf server. Enables rootless container support in Apptainer using in-kernel namespacing.

Use with: rockylinux-ohpc, rockylinux-slurm, rockylinux-openpbs, and any image that includes Apptainer.

chrony

Configures which upstream NTP server the cluster nodes should synchronize time with. As of v1.2.0, the overlay forces synchronization with makestep on first boot - useful when nodes boot with a wildly-wrong clock.

Use with: rockylinux-ohpc and derived images. Set the chrony tag on the node or profile to choose the upstream server.

slurm

Configures which Slurm controller a compute node should attach to (slurmctld address, MUNGE key, cgroup configuration).

Use with: rockylinux-slurm and rlc-slurm images.

openpbs

Configures which OpenPBS server a compute node should attach to.

Use with: rockylinux-openpbs and rlc-openpbs images.

fuzzball-substrate

Configures which shared filesystem Fuzzball Substrate should use for its configuration. This typically points at a configuration export from a Fuzzball Orchestrate cluster.

Use with: rlc-fuzzball-substrate and similar images.

Inspecting an overlay

Each Pro overlay reads a small set of tags from the node or profile. Use wwctl overlay info (Warewulf v4.6.5+) to list them:

# wwctl overlay info chrony
# wwctl overlay info slurm

Attaching an overlay to a profile

# wwctl profile set compute --system-overlays=wwinit,wwclient,hosts,chrony,slurm
# wwctl overlay build

See the upstream overlay usage guide for the full set of overlay management commands.