banger/docs/advanced.md
Thales Maciel 2a7f55f028
vm run: ship tracked files only by default; add --include-untracked + --dry-run
Workspace-mode vm run and vm workspace prepare used to copy both
tracked AND untracked non-ignored files into the guest. That silently
catches local .env files, scratch notes, credentials, and any other
working-tree state a developer hasn't explicitly gitignored — a real
data-exposure footgun given the golden image ships Docker and the
usual dev tooling.

Flip the default to tracked-only. Users who actually want the fuller
set opt in with --include-untracked (documented in both commands'
help). Gitignored files are still always excluded regardless of the
flag.

Add --dry-run to both vm run and vm workspace prepare. Dry-run
inspects the repo CLI-side (no VM created, no daemon RPC needed since
the daemon is always local and the inspection is a pure git read),
prints the exact file list + mode, and exits. A byte-level preview of
what would land in the guest.

When running real (non-dry) and untracked files exist in the repo but
are being skipped under the new default, print a one-line notice
pointing to --include-untracked so users aren't surprised when the
guest is missing something they expected.

Signature changes:
- ListOverlayPaths takes an includeUntracked bool (tracked always;
  untracked gated by flag).
- InspectRepo takes the same flag and passes it through.
- VMWorkspacePrepareParams gains IncludeUntracked.
- WorkspaceService.workspaceInspectRepo seam signature widened to
  match (4 callers in tests updated).

New workspace package tests cover both modes and verify that
gitignored files never leak regardless of the flag.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-21 19:53:17 -03:00

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3.1 KiB
Markdown

# Advanced flows
`banger vm run` covers the common sandbox case. This doc is for the
rest: scripting, arbitrary images, custom rootfs stacks, long-lived
guest processes.
## `vm create` — the low-level primitive
Use when you want to provision without starting, or when you need to
script VM creation piecewise.
```bash
banger vm create --image debian-bookworm --name testbox --no-start
banger vm start testbox
banger vm ssh testbox
banger vm stop testbox
banger vm delete testbox
```
Sweep every non-running VM (stopped, created, error) with:
```bash
banger vm prune # interactive confirmation
banger vm prune -f # skip the prompt
```
`vm create` is synchronous by default, but on a TTY it shows live
progress until the VM is fully ready.
## `image pull <oci-ref>` — arbitrary container images
For images outside banger's catalog, pull from any OCI registry:
```bash
banger image pull docker.io/library/alpine:3.20 --kernel-ref generic-6.12
```
Layers are flattened, ownership is fixed (setuid binaries, root-owned
config preserved), banger's guest agents are injected, and a first-boot
systemd service installs `openssh-server` via the guest's package
manager so the VM is reachable on first boot.
See [`docs/oci-import.md`](oci-import.md) for supported distros,
caveats, and the `internal/imagepull` design.
## `image register` — existing host-side stack
If you already have an ext4 rootfs, a kernel, optional initrd, and
optional modules as files on disk:
```bash
banger image register --name base \
--rootfs /abs/path/rootfs.ext4 \
--kernel-ref generic-6.12
```
You can mix `--kernel-ref` (a cataloged kernel) with `--rootfs` from
disk, or pass `--kernel /abs/path/vmlinux` for a one-off kernel.
For reproducible custom images, write a Dockerfile and publish it to
an image catalog. See [`docs/image-catalog.md`](image-catalog.md).
## Workspace primitive
`vm run ./repo` (see README) handles the common case. For a manual
flow against an already-running VM, `vm workspace prepare`
materialises a local git checkout into the guest:
```bash
banger vm workspace prepare <vm> ./other-repo --guest-path /root/repo
```
Default guest path is `/root/repo`; default mode is a shallow
metadata copy plus a tracked-files overlay. Untracked files are
skipped by default — pass `--include-untracked` to ship untracked
non-ignored files too (the old behaviour). Pass `--dry-run` to list
the exact file set without touching the guest. For repositories with
submodules, pass `--mode full_copy`.
## Inspecting boot failures
When a VM's create flow errors ("ssh did not come up within 90s" or
similar), the VM is kept alive for inspection:
- `banger vm logs <name>` — the firecracker serial console output,
the best window into a stuck boot (systemd unit failures, kernel
panics, missing modules).
- `banger vm ports <name>` — what's listening in the guest. Works as
long as banger's vsock agent has come up, even if SSH is wedged.
- `banger vm show <name>` — daemon-side state (IP, PID, overlay
paths).
`--rm` on `vm run` intentionally does NOT fire when the initial ssh
wait times out, so the VM stays around for post-mortem.