Closes the full arc: banger kernel pull + image pull + vm create + vm ssh
now works end-to-end against docker.io/library/debian:bookworm with zero
manual image building.
Generic kernel:
- New scripts/make-generic-kernel.sh builds vmlinux from upstream
kernel.org sources using Firecracker's official minimal config
(configs/firecracker-x86_64-6.1.config). All critical drivers
(virtio_blk, virtio_net, ext4, vsock) compiled in — no modules,
no initramfs needed.
- Published as generic-6.12 in the catalog (kernels.thaloco.com).
- catalog.json updated with the new entry.
Direct-boot init= override (vm_lifecycle.go):
- For images without an initrd (direct-boot / OCI-pulled), banger now
passes init=/usr/local/libexec/banger-first-boot on the kernel
cmdline. The script runs as PID 1, mounts /proc /sys /dev /run,
checks for systemd — if present execs it immediately; if not
(container images), installs systemd-sysv + openssh-server via the
guest's package manager, then execs systemd.
- Also passes kernel-level ip= parameter via BuildBootArgsWithKernelIP
so the kernel configures the network interface before init runs
(container images don't ship iproute2, so the userspace bootstrap
script can't call ip(8)).
- Masks dev-ttyS0.device and dev-vdb.device systemd units that
otherwise wait 90s for udev events that never fire in Firecracker
guests started from container rootfses.
first-boot.sh rewritten as universal init wrapper:
- Works as PID 1 (mounts essential filesystems) OR as a systemd
oneshot (existing behavior).
- Installs both systemd-sysv AND openssh-server (container images
have neither).
- Dispatch updated: debian, alpine, fedora, arch, opensuse families
+ ID_LIKE fallback. All tests updated.
Opencode capability skip for direct-boot images:
- The opencode readiness check (WaitReady on vsock port 4096) now
returns nil for images without an initrd, since pulled container
images don't ship the opencode service. Without this, the VM
would be marked as error for lacking an opinionated add-on.
Docs: README and kernel-catalog.md updated to recommend generic-6.12
as the default kernel for OCI-pulled images. AGENTS.md notes the new
build script.
Verified live:
- banger kernel pull generic-6.12
- banger image pull docker.io/library/debian:bookworm --kernel-ref generic-6.12
- banger vm create --image debian-bookworm --name testbox --nat
- banger vm ssh testbox -- "id; uname -r; systemctl is-active banger-vsock-agent"
→ uid=0(root), kernel 6.12.8, Debian bookworm, vsock-agent active,
sshd running, SSH working.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Introduces the headline feature of the kernel catalog: pulling a kernel
bundle over HTTP without any local build step.
Catalog format (internal/kernelcat/catalog.go):
- Catalog { Version, Entries } + CatEntry { Name, Distro, Arch,
KernelVersion, TarballURL, TarballSHA256, SizeBytes, Description }.
- catalog.json is embedded via go:embed and ships with each banger
binary. It starts empty (Phase 5's CI pipeline will populate it).
- Lookup(name) returns the matching entry or os.ErrNotExist.
Fetch (internal/kernelcat/fetch.go):
- HTTP GET with streaming SHA256 over the response body.
- zstd-decode (github.com/klauspost/compress/zstd) -> tar extract into
<kernelsDir>/<name>/.
- Hardens against path-traversal tarball entries (members whose
normalised path escapes the target dir, and unsafe symlink
targets) and sha256-mismatch downloads; any failure removes the
partially-populated target dir.
- Regular files, directories, and safe symlinks are supported; other
tar types (hardlinks, devices, fifos) are silently skipped.
- After extraction, recomputes sha256 over the on-disk vmlinux and
writes the manifest with Source="pull:<url>".
Daemon methods (internal/daemon/kernels.go):
- KernelPull(ctx, {Name, Force}) - lookup in embedded catalog, refuse
overwrite unless Force, delegate to kernelcat.Fetch.
- KernelCatalog(ctx) - return the embedded catalog annotated per-entry
with whether it has been pulled locally.
RPC: kernel.pull, kernel.catalog dispatch cases.
CLI:
- `banger kernel pull <name> [--force]`.
- `banger kernel list --available` prints the catalog with a
pulled/available STATE column and a human-readable size.
Tests: fetch round-trip (extract + manifest + sha256), sha256 mismatch
rejection with cleanup, missing-vmlinux rejection, path-traversal
rejection, HTTP error propagation, catalog parsing, lookup,
pulled-status reconciliation. All 20 packages green.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
