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>
New imagepull.InjectGuestAgents writes banger's guest-side assets
straight into the pulled ext4 so systemd will start them at first boot:
/usr/local/bin/banger-vsock-agent (binary, 0755)
/usr/local/libexec/banger-network-bootstrap (script, 0755)
/etc/systemd/system/banger-network.service (unit, 0644)
/etc/systemd/system/banger-vsock-agent.service (unit, 0644)
/etc/modules-load.d/banger-vsock.conf (modules, 0644)
plus enable-at-boot symlinks under
/etc/systemd/system/multi-user.target.wants/
All writes + ownership + symlinks go through one `debugfs -w -f -`
invocation. No sudo required because the caller owns the ext4 file.
Script is deterministic: shallow-first mkdir, then write, then sif,
then symlink. "File exists" errors from mkdir on already-present
dirs are tolerated (debugfs keeps going past them with -f, and we
filter them out of the output scan).
Asset content reuses the existing guestnet.BootstrapScript /
SystemdServiceUnit / ConfigPath and vsockagent.ServiceUnit /
ModulesLoadConfig / GuestInstallPath — one source of truth, no
duplicated systemd unit strings.
Daemon wiring: new d.finalizePulledRootfs seam runs both
ApplyOwnership (B-1) and InjectGuestAgents as one phase between
BuildExt4 and StageBootArtifacts. The companion vsock-agent binary
is resolved via paths.CompanionBinaryPath. Existing daemon tests
stub the seam with a no-op to avoid needing a real companion
binary + debugfs in the test harness.
Tests: real-ext4 round-trip that builds a minimal ext4, runs
InjectGuestAgents, then verifies every expected path is present
via `debugfs stat`, plus uid=0 and mode 0755 on the vsock-agent
binary. Also: missing-binary rejection, ancestor-collection order
test. debugfs/mkfs.ext4 tests skip on hosts without the binaries.
After B-1+B-2, any OCI image that already ships sshd boots with
banger-network and banger-vsock-agent running; image pull is
one step from "useful rootfs primitive". B-3 (first-boot sshd
install) unlocks images that don't ship sshd.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
