One-command sandbox: `banger vm run` on a fresh host now Just Works.
No prior `banger image pull` or `banger kernel pull` needed.
Changes:
- Default `default_image_name` flips from "default" to "debian-bookworm"
so the golden image is the implicit target when `--image` is omitted.
- `CreateVM` resolves the image via a new `findOrAutoPullImage`: try
the local store first, and on miss fall back to the embedded imagecat
catalog + auto-pull. Emits a vm-create progress stage so the user
sees "pulling from image catalog" in the create output.
- `resolveKernelInputs` gains context + the same pattern via
`readOrAutoPullKernel`: try the local kernelcat, and on miss look up
the embedded kernelcat and auto-pull. Fires whenever a bundle's
manifest references a kernel the user hasn't pulled yet, not just
during image pull — any CreateVM with an image that needs a kernel
not yet local will resolve it.
- `--image` help text updated on both `vm run` and `vm create`.
Six tests cover local-hit-no-pull, auto-pull-on-miss, not-in-catalog
error propagation, and a non-ENOENT kernel read error does NOT trigger
a misleading "not in catalog" claim.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
PullImage now checks the embedded imagecat catalog first. If the
ref matches a catalog entry, it takes the bundle path:
1. Fetch the .tar.zst bundle into a staging dir (rootfs.ext4 +
manifest.json).
2. Strip manifest.json (staging-only metadata).
3. Stage kernel/initrd/modules alongside rootfs.ext4.
4. Publish the staging dir and upsert the image row.
Bundle rootfs is already flattened + ownership-fixed + agent-
injected at build time, so the daemon-side work is strictly I/O —
no flatten, no mkfs, no debugfs.
Kernel resolution in the bundle path: --kernel-ref > entry.kernel_ref
> --kernel/--initrd/--modules.
If the ref doesn't match a catalog entry, PullImage falls through
to the existing OCI path unchanged (extracted into pullFromOCI).
New test seam: d.bundleFetch. Six unit tests cover happy path,
--kernel-ref override, existing-name rejection, kernel-required
error, fetch-failure cleanup, and the catalog → OCI fallthrough.
CLI help updated: image pull now documents both forms and takes
<name-or-oci-ref> instead of requiring an OCI ref.
Co-Authored-By: Claude Opus 4.7 (1M context) <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>
imagepull.Flatten now captures per-file uid/gid/mode/type from the
tar headers as it walks layers, returning a Metadata map alongside
the extracted tree. Whiteouts correctly drop the victim's metadata.
The returned Metadata feeds the new imagepull.ApplyOwnership, which
pipes a batched `set_inode_field` script to `debugfs -w -f -`.
Why: mkfs.ext4 -d copies the runner's on-disk uids verbatim, so
without this pass setuid binaries become setuid-nonroot and sshd
refuses to start on the resulting image. With the pass, a pulled
debian:bookworm has /usr/bin/sudo with uid=0 + setuid bit surviving
intact.
imagepull.BuildExt4 signature unchanged; ownership is applied as a
separate step by the daemon orchestrator between BuildExt4 and
StageBootArtifacts, keeping each helper focused. The seam
(d.pullAndFlatten) now returns (Metadata, error) for test stubs to
feed synthetic metadata.
StdinRunner is a new duck-typed extension next to CommandRunner;
the real system.Runner implements RunStdin, test mocks don't need
to unless they exercise stdin. Prevents every existing mock from
growing a new method.
Tests:
- TestFlattenCapturesHeaderMetadata: setuid bit + mode survive the
tar-header walk
- TestApplyOwnershipRewritesUidGidMode: real debugfs round-trip —
create ext4 with runner's uid, apply synthetic metadata setting
uid=0 + setuid mode, verify via `debugfs -R stat` that the
inode now has uid=0 and mode 04755
- TestBuildOwnershipScriptDeterministic: sorted, well-formed
sif script output
Debugfs and mkfs.ext4 tests skip if the binaries aren't on PATH.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
(d *Daemon).PullImage downloads an OCI image, flattens it into an
ext4 rootfs, and registers the result as a managed banger image.
Flow (internal/daemon/images_pull.go):
1. Parse + validate the OCI ref via go-containerregistry/name.
2. Derive a friendly default name from the ref ("debian-bookworm")
when --name is omitted.
3. Reject if an image with that name already exists.
4. Resolve kernel info via the new shared resolveKernelInputs
helper (refactored out of RegisterImage); ValidateKernelPaths
checks the kernel triple alone.
5. Acquire imageOpsMu, generate a fresh image id, and stage at
<ImagesDir>/<id>.staging.
6. imagepull.Pull → cache layers under OCICacheDir;
imagepull.Flatten → temp rootfs tree under os.TempDir (so the
state filesystem doesn't temporarily double in size).
7. Default size: max(treeSize × 1.25, 1 GiB); --size override
accepted.
8. imagepull.BuildExt4 produces the rootfs.ext4 in the staging dir.
9. imagemgr.StageBootArtifacts stages the kernel/initrd/modules
into the same dir (reused unchanged).
10. Atomic os.Rename(staging, finalDir) publishes the artifact dir.
11. Persist model.Image with Managed=true. Failure at any step
removes the staging dir; failure post-rename removes finalDir.
The pullAndFlatten field on Daemon is the test seam: tests stub it
to write a fixture tree into destDir and skip the real registry.
Refactor: extracted the "kernel-ref vs direct paths" resolution
out of RegisterImage into d.resolveKernelInputs so PullImage and
RegisterImage share one source of truth for that policy. Split
ValidateRegisterPaths into a kernel-only ValidateKernelPaths so
PullImage (which produces the rootfs itself) can validate just
the kernel triple without the rootfs check.
API: ImagePullParams { Ref, Name, KernelPath, InitrdPath,
ModulesDir, KernelRef, SizeBytes }. RPC dispatch case image.pull
mirrors image.register.
Tests cover: happy-path producing a managed image with all four
artifacts present + staging cleaned up, name-collision rejection,
missing-kernel rejection, and staging cleanup on a failed pull.
defaultImageNameFromRef handles tag/digest/no-suffix cases.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
