Run-time composition instead of baked-in toolchain combinations: a slim
base image plus per-toolchain prefix binds (--with jdk-21 --with go-1.24),
possible because official toolchain tarballs live under their own
prefixes — plain ro-binds, no overlayfs, no root, today's bwrap.
Comes due when a second toolchain combination is needed; until then the
one fat image stays the deliberate choice.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The minimal build-capable CLI decided in RFC 0002's outcome: stdlib-only
Go module, one static binary.
- engine: RunSpec behind the Engine interface (RFC 0001); the Bwrap
engine ports Werkator's hardened invocation — uid-0 mapping, read-only
rootfs at /, proc/dev/tmp/root before the user binds so binds below
them land inside, mountpoint pre-creation in the rootfs including file
mountpoints, and a guard against binds escaping the rootfs. --clearenv
gives docker-style clean environments (HOME/PATH set explicitly).
- store: images under $WERKDOCK_HOME (default ~/.werkdock), load
unpacks via the tar CLI into a tmp dir and renames atomically.
- cli: docker-shaped run flags (-v/-e/-w/--rm); refused docker flags
(-p, --network, --memory, --cpus, --user, -d) fail loudly with the
reason; exit codes follow docker (125 CLI errors, child code through).
- doctor: port of werkator-build-prerequisites.sh — userns probe with
the three signals, tar/zstd, free space and group-quota headroom via
testable df/quota parsers, same PASS/FAIL output.
- tests: argv golden test, mountpoint and escape tests, flag refusals,
store round trip, doctor parsers — plus real-sandbox integration
tests that skip where bwrap or userns are unavailable.
Also records in step 21: RFC 0002 levels 2/3 deferred; next goal is
sandbox builds of Werkator, Werkbaum, and Werkdock itself.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Level 1: docker-compatible CLI (verbs, flags, loud refusal of isolation
flags the filesystem-only contract cannot honor) — built in session B.
Level 2: OCI image pull, flattened to a rootfs — deferred, stdlib-doable.
Level 3: a daemon speaking the Docker Engine API subset Testcontainers
actually uses (Testcontainers never calls the CLI) — deferred, but the
CLI is built as a thin frontend over the same internal service from the
start. Records the port-mapping crux of host networking and the
unprivileged-netns escape hatch as a future RFC.
Step 21 session B and the werkdock README follow the docker-shaped
semantics: run takes an image, instances correspond to containers.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The full five-way evaluation (bash, Python 3, Kotlin Native, Rust, Go)
with the numeric scoring, the Kotlin Native deep-dive, and the
own-namespaces-instead-of-bwrap analysis, ending in a concrete proposal:
Go, stdlib-only, one static binary, sandbox engine behind an interface
so bwrap can later be swapped for native namespaces.
Status proposed — the decision outcome is recorded once made.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
