Bake immutable Packer golden host image

[t0gun]

Immutable Packer Golden Host Image

Build the immutable Debian 13 minimal bare-metal host image with HashiCorp Packer. Bake in all runtime assets so the host is ready to accept microVM workloads on first boot without dynamic provisioning.

Host Image

• packer/ directory in the repo with HCL template for the SpaceScale bare-metal host
• Debian 13 minimal base
• Deployable bare-metal image format compatible with OVH provisioning
• Offline-capable on first boot
• systemd units and boot ordering for host runtime services
• Local NATS leaf node bootstrap preconfigured

Binaries Baked In

firecracker
jailer
scaled
nats-server
vmlinux
guestd base rootfs

Host Dependencies

systemd
iptables
iproute2
ethtool
util-linux
mount
e2fsprogs
kmod
ca-certificates

Runtime Assets

• Guest vmlinux at /var/lib/spacescale/golden/vmlinux
• Shared guestd base rootfs at /var/lib/spacescale/golden/rootfs.ext4
• Host kernel support for KVM, TAP networking, MMDS, and erofs workload image path
• lz4 as preferred builder-side compression for erofs runtime images

Directory Layout

• /var/lib/spacescale/golden/ — immutable runtime assets (vmlinux, rootfs, firecracker, jailer)
• /var/lib/spacescale/microvms/ — per-VM workspace state
• /var/lib/spacescale/j/ — jailer chroot base