Commit Graph

2 Commits

Author SHA1 Message Date
Logan Johnson
700e690193 feat(db): enforce unique listed channel names with an index (#8787)
## Summary

Stacked on https://github.com/block/buzz/pull/8782 (merged), which makes
the relay refuse a second open channel with a name that another channel
in the community already has. That check lives in relay code, so an
older relay, a direct database write or a missed code path can still
create a duplicate.

This PR adds the same rule to the database: a unique index on channel
name, ignoring case, for the channels that show in the channel list.
With the index in place, a duplicate fails at the write, whatever wrote
it. The relay's own name check from
https://github.com/block/buzz/pull/8782 is no longer needed, so this PR
removes it. Clients still get the same refusal, `invalid: an open
channel named "…" already exists`.

The migration builds the index itself, also on a populated `channels`
table, so an auto-migrating relay upgrades with no operator index step
(the rule from https://github.com/block/buzz/pull/8802). It still
refuses to run while duplicate names remain, because the index cannot
exist over them. `docs/channel-name-uniqueness-deployment.md` gives the
full rollout.

## Details

- **The index** (migration `0083_channels_listed_name_unique.sql`):
  ```sql
  CREATE UNIQUE INDEX idx_channels_listed_name
      ON public.channels (community_id, lower(name))
      WHERE visibility = 'open' AND NOT unlisted
        AND channel_type IN ('stream', 'forum') AND deleted_at IS NULL;
  ```
It covers open, not unlisted streams and forums that are not deleted,
archived ones included. Private channels, DMs and unlisted channels may
still repeat names.
- **The migration builds the index inline, as `0049` does.** When
`to_regclass` finds no index, it runs a plain `CREATE UNIQUE INDEX`
under `lock_timeout` 1s and `statement_timeout` 5s. On a busy or very
large table it fails on those budgets, records nothing, and the relay
retries at its next start. When the index already exists (a concurrent
prebuild), it skips `CREATE` so it never requests the write-blocking
lock. In both cases it then checks that the index is valid, ready and
has the exact expected definition.
- **One refusal stays: duplicate names.** The migration refuses to run
while listed duplicates remain, and its error names the rename script.
The renames must go through the relay so clients get the new kind:39000,
and a migration must not change rows (`docs/database.md` Rule 3). This
is the "fails closed until its repair has run" case in
`migrations/AGENTS.md`, so the writer release from
https://github.com/block/buzz/pull/8782 and the rename are a required
stop.
- **Relay.** A write that takes the name of a concurrent, uncommitted
write waits for it, and fails if that write commits. So the post-write
check and the per-name lock from https://github.com/block/buzz/pull/8782
are removed. The store already maps the index violation to the same
"name taken" error.
- **Desired-state schema.** `schema/tables/public/channels.sql` has the
same index, and the schema parity test compares its live shape between
the desired-state schema and the migrations.
- **Rollout** (`docs/channel-name-uniqueness-deployment.md`), in order:
1. Deploy https://github.com/block/buzz/pull/8782 and wait until no
older relay pod serves.
2. Rename the existing duplicates in each community with that PR's
script, while relays keep serving. The script needs `psql` and
`python3`, and the operator key must be a member of each community. The
doc covers archived communities and communities being deleted.
  3. Confirm that no duplicate remains.
4. Only for a deployment that migrates out of band and is too large for
the budgets: build the index with `CREATE UNIQUE INDEX CONCURRENTLY` and
verify it.
5. Deploy this release. With auto-migration on, the relay applies 0083
at startup. With it off, run `buzz-admin migrate` first, never the file
through `psql`.

Rollback goes to the https://github.com/block/buzz/pull/8782 release
only. Keep the index, and keep auto-migration off.
- **Test fixtures.** Tests that inserted two open channels with one name
now use distinct names. Tests that migrate a populated database through
0083 no longer prebuild the index.

### Related issue

None found. Follows https://github.com/block/buzz/pull/8782.

### Testing

- Migration tests (`listed_channel_name_postgres_tests.rs`) start from a
database migrated through 0082:
  - With duplicates, 0083 fails and changes nothing.
- After the rename plan is applied, a channel writer that holds its lock
makes the inline build fail on the 1s lock budget, with nothing
recorded.
- With no writer, the populated table migrates with no prebuild, and a
raw duplicate insert fails on the index.
- An index with a different definition, and an invalid one, are refused.
A valid prebuilt index is accepted, and not replaced, while another
transaction is writing to `channels`.
- The store and relay name tests from
https://github.com/block/buzz/pull/8782 pass with the relay check
removed: the index refuses the duplicate, and the client still gets
`invalid:`.
- The rename plan and script tests from
https://github.com/block/buzz/pull/8782 run on a database at 0082, the
state the script runs in.
- Local Postgres runs on `108737dc0`, one fresh database per test as the
nextest wrapper does: 38 of 40 buzz-db migration-lane tests pass (both
listed-name tests, the migration parity test, the thread-window and
invite-upgrade tests that migrate populated databases through 0083). The
2 `event_follow_up` contract tests fail locally the same way on main.
All 49 buzz-db channel and channel-member store tests pass.

### Database review checklist

- [x] Phase: contract. Before it:
https://github.com/block/buzz/pull/8782 (writer release, required stop)
and its rename script. Nothing after it.
- [x] No trigger, function, procedure, rule or foreign key.
- [x] No migration mutates rows. The renames happen before it, through
the relay, with the script in https://github.com/block/buzz/pull/8782.
- [x] Never refuses a table because it has rows. Fails closed only with
duplicates (repair not run) or with an invalid or different index; then
0083 raises and the relay does not start. The release notes must name
the release that contains https://github.com/block/buzz/pull/8782 as a
required stop.
- [x] Rule 4: `migrations/`, `schema/tables/public/channels.sql` and the
parity test. A live catalog comparison covers the index.
- [x] Deployed relay: the https://github.com/block/buzz/pull/8782 relay
answers `invalid:` beside the index (its tests pass with the index
present). A relay older than that still writes, but gets a database
error, not `invalid:`, for a duplicate. That is why
https://github.com/block/buzz/pull/8782 is a required stop.
- [x] Timeouts and index build: `lock_timeout` 1s, `statement_timeout`
5s. The migration builds the index inline (plain `CREATE UNIQUE INDEX`,
skipped when `to_regclass` finds a prebuilt one). Only out-of-band
deployments too large for the budgets prebuild it with `CREATE UNIQUE
INDEX CONCURRENTLY` (doc step 4).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Signed-off-by: Logan Johnson <loganj@squareup.com>
Co-authored-by: Larry <627498bd4bd1f281a16431e3c6cce3b5c25b6692798c78672298aefbf2f8f8b5@buzz.block.builderlab.xyz>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-04 22:47:23 -05:00
ravarora2
834dca26bf Generate user community inventory for the dummy deletion workflow (#8605)
## Summary

User deletion can now discover current communities from a hex public key
or npub, save that inventory, and run it through the existing approval
and dummy workflow. `--pubkey demo` remains the default. Execution only
prints messages; it does not fence users or delete data.

Discovery combines explicit relay memberships with active channel
memberships, including users who have no relay membership row. It
deduplicates communities and preserves owner relationships. The saved
manifest contains only community IDs, labels and relationships.
Historical discovery and owned-community execution remain later work.
Submission rejects owner inventories atomically with a specific
unsupported-execution error; preview still includes owners.

This is an expand-schema change after #8520. Migrations 0072–0073
replace the demo-only target check with a bounded identifier check, with
5-second lock and 30-second statement timeouts. The database keeps the
user-only entity-type check while allowing different identity formats in
the target field. Workflow-specific commands reject entity types they
cannot execute. The application currently resolves demo and hex/npub
inputs; account-ID lookup is future work. The desired-state constraint
matches. No backfill, trigger, function, or foreign key is added.
Existing demo rows remain valid. Old binaries fail closed on new
manifests; use the new CLI for their approval and execution. Older
auto-migrating binaries need the documented rollback procedure.

Identity parsing and demo fixture selection stay in intake. Approval and
resume use the saved target without reparsing its format. The user
workflow defines its stage names and handlers; CLI stage validation
reads those rules instead of a separate three-name list. Shared
persistence accepts caller-defined stages. Permanent target uniqueness
is unchanged. Dummy submissions and execution belong in isolated,
disposable development databases; production preview uses read-only
access. CLI operator names remain self-asserted.

### Related issue

Follows #8520. Searched open PRs; no duplicate inventory change found.
#8489 is earlier workflow scaffolding.

### Testing

Built `buzz-admin` locally and applied all migrations to a fresh
disposable PostgreSQL database. Ran the actual CLI through preview →
submit → inspect → approve → `run --next-step` → resume → completed for
both demo and a public key with a channel-only membership fixture. Demo
completed five stages; the public-key run completed three. Injected
`--fail-stage purge_db`, waited for the retry deadline, and resumed the
same failed stage successfully. Membership data remained intact.

Repeated the CLI workflow on October 26 for demo and an npub backed by a
fresh production inventory. Production access used read-only credentials
and the real `inventory --pubkey "$SUBJECT"` handler. Copied only the
relevant discovery fields into an isolated local PostgreSQL database;
local channel parent rows supplied placeholder fields for foreign keys.
The inventory saved by local submission exactly matched the production
result. All workflow writes stayed local.

For each input, ran `submit --pubkey "$SUBJECT" --requested-by
local-e2e-submitter`, inspected the saved inventory, and confirmed
execution before approval was rejected. Approved its digest, then ran
each handler with `run "$REQUEST_ID" --next-step --stage-delay-ms 2500`
in a new process. Captured all three workflow tables during and after
every stage. Demo completed five stages across two communities; the npub
completed three stages for its discovered community. Each handler saved
`dummy: true`. Both requests finished with no current stage, no worker
lease, and no retries. Copied memberships remained intact. This
additional run exercised orderly resume; it did not inject a failure.

The reproducible command sequence and fixture setup are in [the
inventory walkthrough](docs/operator-user-deletion-inventory.md).
Production was not changed. The earlier full-workflow runs used
synthetic local fixtures; the additional npub run used captured
production discovery fields. Repository-wide `just ci` was not run;
validation focused on the affected packages and PostgreSQL workflow. The
pre-push desktop build failed with “Too many open files in system.”
Stopped the broader hook run and bypassed it to publish the earlier
commits; the affected-package Clippy and formatting checks had passed.

Generated with Codex

---------

Signed-off-by: Ravneet Arora <rarora@squareup.com>
2026-10-26 15:44:12 -04:00