PRD 0018 chunk 3's atomicity fix used write-temp-then-rename to
update bind-mounted config files. POSIX rename atomically swaps
the inode at the host path — but Docker single-file bind mounts
on Linux pin the source inode at mount time, so post-rename the
container's mount points at the now-orphaned old inode and never
sees the new content. The egress sidecar's SIGHUP-driven reload
re-reads the same stale file → "egress route updates aren't
updatable via the supervisor anymore".
Switch egress_apply + pipelock_apply to write in place (same
inode, truncated + rewritten). Lose file-level POSIX atomicity,
but:
- egress: SIGHUP fires only AFTER the write returns; the
addon's `load_routes` raises `ValueError` on a partial read
and keeps the previous in-memory routes, so the in-process
race window (already narrow) is non-disruptive.
- pipelock: applies via `docker restart` rather than SIGHUP;
restart serializes after the host write completes, so the
container reads the fully-written file on next boot.
macOS Docker Desktop's file-sharing layer (virtiofs / osxfs)
silently re-resolves the path on rename, which is why this bug
didn't surface in dev tests on macOS. Linux native Docker is
the strict reading; the fix works on both.
`egress_render_routes` now emits hand-rolled YAML in the same style
as `pipelock_render_yaml`. The egress addon parses it via
`yaml_subset.parse_yaml_subset` — the same parser the manifest
loader + pipelock_apply use.
Why bother: routes.yaml is bind-mounted into the egress sidecar
AND surfaced to operators through `routes edit` (PRD 0019). JSON-
in-yml renders ugly in $EDITOR and signals "this is data" rather
than "this is config you can read at a glance". Real YAML reads
cleanly.
Mechanics:
- `yaml_subset.py` drops its `claude_bottle.log` dependency.
Errors now raise `YamlSubsetError` (a `ValueError`); the
manifest loader + pipelock_apply catch it at the boundary
and forward to `die` / `PipelockApplyError` so callers see
the same behavior they did before.
- `Dockerfile.egress` adds one COPY line for `yaml_subset.py`
so it sits flat in `/app/` next to the addon. The addon
uses an absolute-import-with-fallback shim so the same file
works inside the container AND from the host's unit tests.
- `egress_apply._merge_single_route` round-trips current
routes.yaml through `parse_yaml_subset` + a new
`_render_routes_payload` helper instead of `json.loads` +
`json.dumps`.
End-to-end: rebuilt the egress image, ran `./cli.py start` to a
full bring-up, confirmed the addon's boot log shows `egress:
loaded 9 route(s)` — i.e., the YAML parses inside the container.
453 unit + 3 integration tests pass.