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>
New internal/imagepull/assets/first-boot.sh: POSIX-sh oneshot that
detects the guest distro from /etc/os-release (ID + ID_LIKE
fallback), installs openssh-server via the native package manager,
and enables/starts sshd. Covers debian/ubuntu/kali/raspbian/pop,
alpine, fedora/rhel/centos/rocky/almalinux, arch/manjaro, and
opensuse/suse. Unknown distros fail clearly with a pointer at
editing the script to add a branch.
Marker-driven: the service has ConditionPathExists=
/var/lib/banger/first-boot-pending, and the script removes the
marker on success. Subsequent boots no-op.
Testability seams in the script: RUN_PLAN=1 skips the
sshd-already-present short-circuit and makes the dispatch echo the
planned command instead of executing it. OS_RELEASE_FILE and
BANGER_FIRST_BOOT_MARKER env vars override paths so the Go tests
exercise the real dispatch logic in a tempdir without touching
/etc or /var/lib on the host.
Embedding: internal/imagepull/firstboot.go go:embeds both the
script and the systemd unit; exposes FirstBootScript() and
FirstBootUnit() plus the FirstBootScriptPath /
FirstBootMarkerPath / FirstBootUnitName constants.
Injection: InjectGuestAgents now drops /usr/local/libexec/
banger-first-boot (0755), /etc/systemd/system/banger-first-boot.
service (0644), the empty /var/lib/banger/first-boot-pending
marker (0644), and the multi-user.target.wants enable symlink.
All uid=0, gid=0.
Tests: eight-case dispatch-by-distro (debian, ubuntu, alpine,
fedora, arch, opensuse, plus ID_LIKE fallbacks for weird
derivatives). Script syntax check via `sh -n`. Unit-contains-
expected-fields check. Existing inject round-trip test extended
to assert the first-boot bits land in the ext4.
Deferred: per-image FirstBootPending flag + extended SSH wait
timeout at VM start. Will add if live verification (B-4) shows
the naive retry UX is unacceptable.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
