The devcontainer comments had grown dense and jargon-heavy. Rewrite them
across all 9 files into short, plain-English sentences — same facts and
reasoning, just clearer wording.
Comments only; no code changed. Verified: the diff touches comment lines
only, 25/25 config-transform tests pass, devcontainer.json is still valid
JSONC with build.args + readonly mounts unchanged, shell scripts pass
`bash -n`, and prettier is clean.
Follow-up to a local branch review (run after the cloud review crashed before
producing findings); all 5 confirmed findings were low/nit:
- chown via `find -xdev -exec chown -h`: add -h so chown acts on a symlink
ITSELF, not its target. Without it a dangling node_modules/.bin link aborted
provisioning under `set -e`, and a cross-fs symlink target could be
dereferenced/rewritten. Verified in a clean container (regular files still
chowned; dangling link no longer aborts; cross-fs target untouched). Applied
to install-deps.sh and post-create.sh; the inline comments are corrected to
describe -xdev (descent bound) and -h (no deref) as the two distinct guards.
- Reword the .cjs header claims from "lintable" to "unit-tested and
prettier-checked": ESLint applies no rules to .cjs in this repo; CI only
prettier-checks them.
- README: the initializeCommand is `node ensure-host-config-dirs.cjs`, which
creates the full bind-source set, not a bash `mkdir -p` of four dirs.
- ci-devcontainer.yml: document that the x64 runner exercises only the amd64
Cursor branch; the arm64 sha/URL is hash-pinned (verified against the
published artifact) but not built in CI.
- Make the seed chmod-644 test meaningful: pre-create dst at 0o600 so only the
explicit chmodSync can widen it (the prior assertion passed under the default
umask regardless of whether the chmod ran).
25/25 config-transform tests pass; arm64 + x64 Cursor artifacts verified.
Resolves the blocking + actionable findings from the PR #1875 review:
- Pin base image by digest as bare name@digest [#1]. The :tag@digest form
trips the @devcontainers/cli image-name parser (which builds this image
in CI and in VS Code "Reopen in Container"); bare name@digest is the
parser-compatible form. Verified by a full local build.
- Pin Cursor by version + per-arch sha256 and fetch the artifact directly
instead of executing cursor.com/install; fail-closed on mismatch [#2].
- Mount ~/.config/gh and ~/.docker read-only so a compromised dep can't
rewrite the host GitHub token / Docker credHelper [#4].
- Pin @devcontainers/cli@0.87.0 in the CI smoke [#5].
- chown via find -xdev in install-deps.sh (symlink-safe; matches
post-create.sh) [#6].
- Add filesystem-I/O tests (translate/readHostConfig/seed main/ensurePaths)
and refactor ensure-host-config-dirs to be unit-testable [#7].
- Stop pre-creating settings.json/config.toml on the host; only the real
single-file bind source (.claude.json) is touched [#10].
- Add a prominent top-of-README security callout for the RW write-through
trade-off and reframe the deferred egress firewall as the key missing
compensating control [#3, #9].
Full devcontainer build verified locally (digest pull + pinned Cursor
download/extract/symlink). 24/24 config-transform tests pass.
- zizmor `artipacked` (CodeQL/GitHub Advanced Security) flagged both
actions/checkout steps in ci-devcontainer.yml: checkout defaults to
persist-credentials:true, leaving GITHUB_TOKEN in .git/config where it
can leak into uploaded artifacts. Both jobs are read-only (run tests /
build smoke, never push), so persist-credentials:false is correct —
matches the repo convention in codeql.yml / ci-tests.yml.
- Ran prettier 3.8.0 over the new .cjs modules + test (single-quote/style
normalization to match the repo). JSON/YAML were already compliant;
README is in .prettierignore; .sh has no prettier parser. Behavior
unchanged — 12/12 transform unit tests still pass.
Multi-agent review (9 reviewers) found the devcontainer files carried
comments + README from the abandoned read-only-symlink design, plus real
behavioral gaps. Resolved all actionable findings (no deferrals).
Documentation drift (the headline — stale comments described a security
model opposite to what shipped):
- README "Trust boundary" claimed a malicious dep "cannot write back …
the read-only /host mount blocks the write." FALSE — the shareable dirs
are RW-bound. Rewrote to document the bidirectional write-through, what
stays one-way (credentials never flow back), and how to close it.
- devcontainer.json mount group-1 comment described "selectively symlinks
… read-only eliminates write-through" — replaced with the RW-bind reality.
- Header "Windows-native is unsupported" -> supported (auto HOME setup).
- containerEnv comment "credentials persist in host-bind-mounted dirs" ->
they live in the named volumes.
- hooks.json exclusion documented honestly as a partial mitigation, not a
clean boundary (commands/agents/skills/rules are equally executing).
- ~/.local "named volume" -> image directory.
Behavioral fixes:
- chown -R recursed into the RW host binds (could rewrite host ownership /
EPERM-abort provisioning on non-UID-aligned Linux). Switched to
`find -xdev` per dir so chown stays on the volume filesystem.
- Cursor installer wrapped in `timeout 300` — its inner binary download
isn't covered by curl --max-time and could hang docker build forever.
- Removed dead CURSOR_VERSION ARG/ENV/build-arg (never consumed; "latest"
implied a pin the installer can't honor). Documented why Cursor is unpinned.
Extraction + tests (the two inline post-create.sh node heredocs were
unlintable and untestable; the path regex had had bugs):
- seed-claude-config.cjs — installMethod-strip seed, now with a non-object
guard (a bare-value/array host .claude.json could otherwise slip the
try/catch and silently re-trigger onboarding) and labeled write errors.
- translate-plugin-registries.cjs — plugin-registry path translation with
labeled errors.
- translate-plugin-registries.test.cjs — 12 tests (Windows/POSIX paths,
cross-CLI isolation, nested objects, non-object/empty-config guard).
- post-create.sh calls the modules via $SCRIPT_DIR.
CI:
- .github/workflows/ci-devcontainer.yml — runs the unit tests + shell
syntax checks + a `@devcontainers/cli build` smoke on .devcontainer/**
changes. Conforms to the repo concurrency convention (validator passes).
Documented (real gaps, fixes are honest docs since no correct auto-fix
exists): user-scope MCP servers with absolute host command paths don't
resolve in-container; user-scope config is copy-on-create so host edits
need a rebuild; in-container plugin installs get shadowed by an empty host
bind on rebuild (recovery noted); plugin installs are single-writer across
checkouts; gh/docker RW-vs-ssh/aws/azure-RO rationale.
Verified: fresh `@devcontainers/cli up` succeeds; installMethod stripped,
registry translated to Linux paths, credentials node:node, 12/12 tests pass.
