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substrate/hack/microvm-assets
Benjamin Elder f7f8727ae8 microvm: bump runtime assets to kata 4.0.0 + virtiofsd v1.14.0 (#506)
- We no longer need to compile virtiofsd when installing for amd64, we
still need to for arm64 (no upstream release)
- Drop-in compatible, only updating the scripts that manage obtaining
the binaries, and the versions / hashes in the config.

- [x] Tests pass
- [x] Appropriate changes to documentation are included in the PR
2026-07-23 18:45:08 -04:00
..

Micro-VM runtime assets + counter demo (kind, fetch-not-bake)

The microvm runtime (cmd/ateom-microvm, kata + cloud-hypervisor) fetches its toolchain at runtime — nothing kata-specific is baked into the worker image. ateom drives the kata-agent directly (no kata shim, no containerd). Each actor container's rootfs is an overlay of a read-only lower (the OCI image, served into the guest over virtio-fs by virtiofsd) and a writable upper on a guest tmpfs, so virtiofsd is part of the asset set. The asset set is five files:

  • cloud-hypervisor — the VMM binary (fetched from its release)
  • virtiofsd — the virtio-fs daemon serving the RO lower (built from source; see assemble.sh)
  • vmlinux — the guest kernel (from kata-static)
  • rootfs.img — the guest rootfs image (from kata-static)
  • configuration-clh.toml — the base kata config (from kata-static)

These helpers assemble the asset set for your node arch, stage it into the cluster's rustfs S3 bucket, and the demo manifest's SandboxConfig points at it. When /dev/kvm is available, hack/create-kind-cluster.sh mounts it into the node and labels the node ate.dev/sandboxClass=microvm.

Tip

hack/run-microvm-demo.sh automates the full bring-up below (assets, control plane, demo apply) for kind OR GKE without editing committed files. The steps here are the manual equivalent.

Steps (run on a KVM-capable Linux host matching the node arch)

  1. Assemble assets for your arch:

    ARCH=arm64 hack/microvm-assets/assemble.sh
    

    Copy the printed sha256 sums into the SandboxConfig spec.assets in demos/counter/counter-microvm.yaml.tmpl (the committed values are arm64; other arches differ).

  2. Bring up the cluster + control plane:

    hack/create-kind-cluster.sh        # mounts /dev/kvm, labels node ate.dev/sandboxClass=microvm
    hack/install-ate-kind.sh           # control plane + rustfs (bucket: ate-snapshots)
    
  3. Stage assets into rustfs:

    OUT="$PWD/microvm-assets-arm64" hack/microvm-assets/stage-to-rustfs.sh
    
  4. Apply the demo + drive it:

    BUCKET_NAME=ate-snapshots envsubst < demos/counter/counter-microvm.yaml.tmpl | kubectl apply -f -
    

    Create an actor from counter-microvm, hit the in-RAM counter to increment it, suspend (checkpoint), resume on a different worker pod, and confirm the count continues — proving the guest-memory snapshot round-tripped across pods.

Notes

  • assets is single-arch (unlike runsc's amd64/arm64): stage assets matching the node arch.