ipodderx-rs/CLAUDE.md

Working on ipodderx-rs

Notes for whoever picks this up next. Read docs/architecture.md for how the thing is built; this file is about working on it without repeating mistakes that have already been made here.

Where things are

Production is the iPodderX container on Tower (192.168.1.130), the ipodderx service of the Arcane project content: /mnt/fast/arcane/projects/content/compose.yaml. That file is what runs; docker-compose.yml in this repo is a copy, and editing it changes nothing in production.

	Host	In the container
Image	192.168.1.130:5000/ipodderx:latest
Config	/mnt/fast/appdata/ipodderx/config.toml	/config/config.toml
Database	/mnt/user/ipodderx/state.db	/data/state.db
Downloads	/mnt/user/ipodderx/downloads	/downloads
Web UI	192.168.1.130:8099, also ipodderx.sdf1.net via a Cloudflare tunnel	0.0.0.0:8099

Deploying a change is: build and push the image, then pull it and recreate the container.

docker buildx build --tag 192.168.1.130:5000/ipodderx:latest . --push
docker compose -f /mnt/fast/arcane/projects/content/compose.yaml pull ipodderx
docker compose -f /mnt/fast/arcane/projects/content/compose.yaml up -d ipodderx
docker logs --tail 20 iPodderX

Name the service. A bare up -d recreates every container in content, beets and immich included. Run pull before up, because up reuses whatever latest the host already has.

A build that fails with 429 Too Many Requests on a base image is Docker Hub rate-limiting this host. There is no Docker Hub login here, and the build asks about debian:bookworm-slim and rust:1-slim-bookworm every time unless they are already stored locally. Pull them from Google's mirror and tag them; the build then uses the local copies without asking Docker Hub:

docker pull mirror.gcr.io/library/debian:bookworm-slim
docker tag mirror.gcr.io/library/debian:bookworm-slim debian:bookworm-slim
docker pull mirror.gcr.io/library/rust:1-slim-bookworm
docker tag mirror.gcr.io/library/rust:1-slim-bookworm rust:1-slim-bookworm

Run those again now and then, or the local copies go stale.

The healthcheck runs ipx status against the control socket, so (healthy) in docker ps means the worker is alive, not just the web port. The container restarts on its own after a reboot.

Before the container, ipx ran by hand in code-server, with its files in /config/.config/ipx/ and /config/.local/share/ipx/. Those are still there and the container does not read them. If you run a daemon by hand for testing, stop it with pkill -x ipx, never pkill -f ipx. -f matches the shell running the command and kills the session (exit 144). This has happened more than once.

Before you touch the page

web/index.html is include_str!d into the binary, so every page change needs a rebuild before it is visible. It is one file: markup, CSS and script.

After any edit to it:

node tests/page-smoke.js

That loads the script against a stub DOM and checks every selector it wires at load actually exists. It exists because a patch once anchored on a deleted function, String.replace silently matched nothing, and the whole UI died with a ReferenceError while every server-side test passed.

Patching that file by guessing an anchor string has failed repeatedly. Read the exact block first (sed -n 'START,ENDp'), match it verbatim, and assert the replacement happened rather than hoping.

Tests

cargo test                # ~51 tests: parsing, filters, retention, schedules, SQL, per-user state
node tests/page-smoke.js
npx playwright test       # 16 browser tests against a real daemon on fixture feeds

Things about the browser suite that have cost time:

• It starts its own daemon and database under /tmp/ipx-ui-test, wiped once per run. Playwright re-imports the config in every worker, so prepare() guards on TEST_WORKER_INDEX — without that guard a worker deleted the database out from under the running daemon, which then kept serving from the unlinked inode while everything else saw an empty file.
• Tests share that daemon and run in order. A test that opens an item marks it read and changes what later tests see. Write assertions that do not depend on what ran before, or normalise the state first.
• Fixture feeds must not share an enclosure URL, because enclosures.url is globally unique and whichever feed is scanned first claims it.
• webServer starts before globalSetup, which is why the fixture config is written at config-load time instead.

Non-trivial logic leaves one runnable check behind. Pure functions (merge_policy, pick, matches_keywords, parse_interval) are the easiest place to put it.

Things that are true and easy to get wrong

• enclosures.url is globally UNIQUE. It is the dedupe key and the reason one file serves every subscriber. Two feeds publishing the same URL means only the first one scanned shows it.
• Read state lives in entry_state, per user, and nowhere else. entries had read, flagged and position columns from before accounts; two bugs came from queries still reading them (retention, and the entry pruner), and migrate() now drops them.
• The catalogue is config.toml; the subscriptions are in the database. A feed exists once; subscriptions(user_id, feed_id) says who wants it and with what settings. OPML children are derived and never written to config.
• One fetch serves everyone, so scan policy is a union of subscribers' wants (merge_policy). Anyone wanting an item is enough to fetch it.
• The UI hiding a control is not enforcement. Admin-only actions check user.is_admin in the handler and return 403.
• A tokio::select! only races its branches at the point of selection. A long download has to watch the shutdown channel itself; the daemon ignored SIGTERM for exactly this reason.
• Only one daemon per socket. Removing the socket file defeats the guard and you get two daemons fighting over the database, with the stale one still holding the port.
• /api/settings answering 200 does not mean the worker is alive — it is a different task. Probe the control socket (ipx status) to check that.
• Every ipx command runs migrate() when it opens the database, the healthcheck's ipx status included. A migration that rewrites a big table (DROP COLUMN) takes seconds on production, and a command run meanwhile fails with migrating schema. It changes nothing; wait for daemon started in the log. Copy state.db aside before deploying one.

House style

Comments explain why, not what. If a line looks odd, the comment says what went wrong without it. No emoji, no exclamation marks, no "obviously". Prose in the UI and docs is plain English and addressed to the person using it.

Every change gets one line under ## [Unreleased] in CHANGELOG.md, in its Keep a Changelog group: Added, Changed, Deprecated, Removed, Fixed or Security. Say it the way someone using ipx would notice it. When there is more to say, such as what was wrong before or what it cost to find out, write it up at the top of docs/history.md, dated. That record has been more useful than the git log more than once.

Cutting a release: rename [Unreleased] to ## [X.Y.Z] - YYYY-MM-DD and open a new empty [Unreleased] above it, bump version in Cargo.toml, tag the commit vX.Y.Z, and update the compare links at the bottom of the changelog.

Deliberate simplifications get a ponytail: comment naming the ceiling and the upgrade path, e.g. // ponytail: global connection mutex, move to a pool if feed count makes it contend.

Known gaps

• Cloudflare's Cf-Access-Jwt-Assertion is not verified — ipx trusts the hop plus trusted_proxies (documented in docs/sso.md).
• A feed's <description> subtitle is dropped whenever content:encoded exists, which loses Substack-style subtitles.