Files
buzz/crates/buzz-db/src/error.rs
T
8a2c9af2db feat(deletion): add durable whole-community deletion (#4425)
## Summary

Adds a durable, operator-controlled V1 for deleting an entire Buzz
community without deleting another tenant's data.

The workflow is exposed through `buzz-admin deletions`:

- `sweep` records independent fleet storage-taxonomy observations
- `submit`, `list`, `inspect`, and `approve` manage a deletion request
- `unblock` resumes a fail-closed request after an operator records
remediation identity and reason
- `run` and `drain` execute bounded work

Requests advance through a PostgreSQL-backed state machine and stop at
`retention_pending` after logical deletion has been independently
verified across PostgreSQL, object storage, and Redis.

This PR ships the engine and CLI, not a continuously running worker or
Kubernetes packaging. For V1, a cluster/VM administrator invokes
`/usr/local/bin/buzz-admin` from the existing relay image, for example
with `kubectl exec` or an equivalent container/VM exec path.

## What whole-community V1 removes

For the target community, V1 removes:

- rows from the allowlisted community-scoped PostgreSQL catalog,
including members, profiles, authored events and bodies, DMs, reactions,
mentions, memberships, tokens, workflows, moderation, audit, feedback,
and rate-limit state
- media sidecars and upload-attribution records under
`_meta/<community>/` and `_uploads/<community>/`
- Git repository pointers under `repos/<community>/`
- Redis keys under `buzz:<community>:*`

The community row survives as a permanent tombstone, and deletion
control-plane records remain as evidence of the request, approval,
execution, and result.

## Safety model

Deletion is not a broad `DELETE CASCADE` followed by optimistic cleanup.
The destructive boundaries are durable and fail closed.

### 1. Inventory and approval

- `submit` resolves the target and freezes the schema plus summary-only
storage inventory.
- Approval is bound to the exact request, community, and frozen
inventory digest.
- Unsupported manifest versions, malformed keys inside the target's
owned prefixes, live scoped-table/write-fence coverage drift,
frozen-inventory mismatch, and approval mismatch block execution rather
than guessing. Migration and catalog revision numbers are not
authorization gates; the executor validates the live safety shape
instead.
- Storage inventory is server-side prefix scoped to exactly:
  - `_meta/<community>/`
  - `_uploads/<community>/`
  - `repos/<community>/`
- The deletion path never lists the whole shared bucket and has no
arbitrary per-community object cap. Its listing work is proportional to
the target community's bindings, not total fleet storage.
- Fleet-wide taxonomy sweeps remain independent observability. They
report unknown writer shapes but do not gate deletion submission,
fencing, or destructive progress. Maintainers must add deletion taxonomy
coverage whenever a new community-owned object-key class is introduced;
writer-coverage tests bind the current media and Git writers to that
contract.

### 2. Quiesce, fence, and destructive freeze

- Writes continue through submission, inventory, and approval. They stop
when execution moves the target into `quiescing` and then establishes
the durable fence.
- Already-admitted external effects finish under heartbeated
serving-write leases; the exact admitted lease may renew while the
community is quiescing, but new lease acquisition is rejected. The
executor drains admitted leases before destructive work.
- Invite minting after quiescing begins fails as typed `AccessDenied`
(HTTP 503 at the relay boundary) before an invite can be persisted.
- Database triggers enforce the community write fence across the
complete catalog of community-scoped tables. Startup/readiness and
destructive execution validate that catalog so a newly added but
unfenced table cannot silently escape.
- **Named isolation assumption — fresh write snapshot.** Every writer
transaction that can reach a community-fenced relation must use
PostgreSQL `READ COMMITTED`; each guarded write therefore observes a
statement snapshot no older than acquisition of the community deletion
lock. `REPEATABLE READ` and `SERIALIZABLE` can retain a pre-fence
snapshot and are unsupported for writers. The writer pool refuses
non-`READ COMMITTED` sessions at connection setup, and both SQL fence
functions reject an explicit per-transaction isolation override with
SQLSTATE `25000`. Configuration-delivered bad isolation can surface
through SQLx as a pool-acquire timeout because every `after_connect`
attempt is rejected; the precise `community writes require READ
COMMITTED isolation` reason remains observable when the SQL guard is
reached. Read-only replica transactions are outside this assumption.
- Holding the shared advisory lock until the guarded write executes is a
separate liveness condition: under `READ COMMITTED`, releasing it early
does not permit resurrection because the trigger rechecks the fence, but
it can turn a fleet sweep into a statement-wide SQLSTATE `55000` abort.
- After the fence closes writers, storage is re-enumerated into chunked
side-table rows. Per-prefix counts and digests bind those concrete keys
to the destructive manifest.
- Manifest chunk insertion, update, and deletion are protected after
freeze. This closes the race where an unbound key could otherwise appear
after the manifest was committed.

### 3. Checkpointed destruction

- Target-owned object bindings are deleted from the frozen destructive
manifest in bounded batches with durable progress.
- The concrete key list lives in chunked side-table rows rather than one
request-row JSON value. It supports large communities, resumable
execution, and terminal cleanup.
- Missing objects are accepted as idempotent crash-window outcomes;
malformed ownership, changed evidence, and unexplained target-prefix
drift fail closed.
- PostgreSQL purging remains scoped by `community_id`, including the
guarded NIP-RS hard-delete path discovered with real Desktop kind
`30078` read-state data.
- Redis cleanup explicitly scans and `UNLINK`s only
`buzz:<community_id>:*`. Natural expiry is insufficient because some
keys, including tunnel generation counters used as fencing state, are
deliberately persistent.

### 4. Independent verification

- PostgreSQL logical absence is checked after purge.
- The three target-owned storage prefixes are freshly inventoried again
and must be empty.
- Redis requires two complete empty namespace scans.
- Only after all three stores pass does the request advance through
`logically_verified` to `retention_pending`.

## What V1 deliberately does not erase

### Shared content-addressed storage

Per-community deletion removes bindings, metadata, attribution records,
and Git pointers. It does **not** physically delete fleet-shared CAS
bytes that another community may still reference:

- media blobs and thumbnails
- Git manifests, packs, and indexes (`manifests/`, `packs/`, and `idx/`)

Safe reclamation requires a separate fleet-wide reachability and
retention GC. Unknown keys elsewhere in the shared bucket do not block
one community's deletion; malformed or unrecognized keys inside that
community's three owned prefixes still fail closed.

### External retained copies

The online logical-deletion proof does not erase object
versions/replicas, database backups/WAL, CDN copies, provider retention
copies, or observability exports. Those require their own retention and
purge controls.

### Member-only erasure

This PR erases a whole community. It does not implement the different
operation "erase one npub while preserving the community."

Removing membership or accepting NIP-09 is not member erasure. A
member-only workflow would need to find and selectively remove or redact
authored event content and pubkeys, profile data, DMs, reactions,
mentions, memberships/roles, tokens, workflows/subscriptions, upload
attribution, moderation/audit history, repository attribution, and
identity embedded in tags or JSON. It would also need explicit rules for
ownership transfer, surviving replies and thread metadata, audit-chain
integrity, immutable Git history, and shared-CAS reachability. That
requires a pubkey-level fence and selective graph rewrite; it is a
separate deletion product, not a safe extension of this whole-tenant
worker.

## In scope

- migration `0029_community_deletion.sql`: requests, approvals, leases,
manifest chunks, checkpoints, tombstones, and the universal write-fence
catalog
- durable executor leases, generations, heartbeats, retry/block state,
and resumable stage transitions
- operator-driven `sweep`, `submit`, `list`, `inspect`, `approve`,
`unblock`, `run`, and `drain` commands
- serving-path fences for database writes and external effects across
event ingest, media, Git, workflow, push, invites, mesh/tunnel, and
related paths
- target-prefix-only storage inventory, summary manifests, post-fence
destructive chunks, and bounded batch deletion
- exact community Redis namespace purge and two-pass absence
verification
- cross-community isolation, crash/resume, manifest-integrity,
writer-taxonomy, and schema/migration regressions
- desired-state `schema/schema.sql` support without requiring a SQLx
migration ledger

## Deferred / not covered

- dedicated Helm/chart worker Deployment, service account, secrets,
probes, resources, and network policy
- autonomous `buzz-admin deletions worker` poll loop and worker-only
health server
- least-privilege separation among migration, relay-serving, and
destructive execution roles
- fleet-wide shared-CAS physical GC
- backup/provider/CDN/observability retention completion
- member-only erasure
- provider-native conditional-delete improvements
- a general force-continue escape hatch; permanent safety failures
remain fail closed unless an operator remediates the cause and records
an audited `unblock`

The removed continuous-worker implementation remains deferred; no remote
follow-up branch is claimed by this PR.

## Validation

### Current PR head and repository state

Current pushed head: `359d8402ee15f049768f54156f67b953c7a7e2ed`, rebased
onto `cc9a2f783375e51a6e8d1f2f9d01d5f7e22813d1` (`origin/main` at push
time). The complete PR diff is now 47 files, 9,834 additions, and 517
deletions.

The bespoke source-scanner stack was removed to keep this PR scoped to
community deletion. Tyler/team requested the underlying fenced-write
safety behavior, not `ast-grep`,
`crates/buzz-db/tests/community_fenced_writes.rs`, its 27 fixtures, or
the new `scripts/lints/community_*.yml` rules. Those scanner-specific
files, dependencies, Hermit links, and runner wiring are absent from the
current tree. The production database write fence, startup/destructive
live-catalog validation, and deletion behavior remain.

Source validation on this exact SHA passed:

- `cargo fmt --all -- --check`
- `bash -n scripts/run-tests.sh`
- `cargo nextest run -p buzz-db --all-targets`: 102 passed, 173 skipped,
0 failed
- `cargo nextest run -p buzz-deletion --all-targets`: 10 passed, 9
skipped, 0 failed
- `cargo nextest run -p buzz-admin --all-targets`: 1 passed, 0 failed
- affected-package/all-target Clippy with warnings denied
- lockfile consistency
- Helm 3.16.4 lint and all 44 chart unit tests
- Helm region controls using that fixture: default
`BUZZ_S3_REGION=us-east-1`, explicit `eu-west-2` override, and
blank-region schema rejection

The prior Kubernetes battery below was run against
`928992237358a3294621ac0280830b77155abc04`. It remains useful evidence
for the patch-equivalent production deletion implementation, but it is
**not** claimed as exact-SHA evidence for current head
`359d8402ee15f049768f54156f67b953c7a7e2ed`; the current cleanup removes
only scanner/test/tooling infrastructure. CI restarted for the new head
after the rebase and is pending. Human review remains
`CHANGES_REQUESTED`.

### Prior-head live Kubernetes deletion and safety gates

The full program used one immutable image, real PostgreSQL, Redis,
MinIO, and a three-relay Kubernetes release:

- source: `928992237358a3294621ac0280830b77155abc04` (**prior head**)
- image: `buzz-e2e:sha-928992237358`
- immutable image digest:
`sha256:a1a204f4618ac22d9e210be5e5290645a15d79831ae30b0e44379357c8e4a895`
- evidence root:
`/tmp/buzz-e2e/20260807T033025Z-928992237358-full-gates/`
- evidence-manifest digest:
`82875c5bc9bea7370b796a7aef3457b3a1c8306c84c59e0f7388bbb5ad30e865`

Passed gates at that prior head:

- **Chart/operator region:** default `us-east-1`, explicit nondefault
propagation, blank-region schema rejection, live in-pod environment, and
an in-pod taxonomy sweep over 18 objects with zero unknown.
- **Fenced writers and lifecycle:** open-write/fence ordering;
100-attempt anti-starvation; invite, push matcher, and exhausted-reaper
bystander isolation; non-`READ-COMMITTED` rejection; manifest/tombstone
contracts; eight-failure stage block and audited `unblock`.
- **Destructive lifecycle:** submit → approve → run →
`retention_pending`; PostgreSQL tombstone and Redis/S3 verification
true; zero retries/errors; terminal reruns rejected with exit 5.
- **Fresh 10,001-object crash boundary:** exactly two chunks (10,000 +
1). The executor deleted chunk 0 from MinIO while its PostgreSQL stamp
was row-lock-blocked, was killed with `SIGKILL`, left one object and
both stamps absent, then resumed the same request under generation 2 to
zero objects and terminal state.
- **Independent dead-owner recovery:** a dedicated executor claimed
generation 1, blocked before effects, and was killed through containerd
with `SIGKILL` (no TERM cleanup). The request remained owned and
unreclaimable before lease expiry; a successor claimed generation 2
after 60 seconds and completed with two attempts and zero retries.
- **Three-pod socket isolation:** ordinary NIP-42 and joined
huddle-audio target witnesses on every replica received exact `1008 /
community deleted`; healthy-tenant witnesses on those pods remained
live; deleted-host reconnect returned HTTP 404.
- **Health/provenance:** all replicas independently returned ready and
retained the exact image digest before/after destructive runs and an
audio-enabled rolling restart; PostgreSQL, Redis, and MinIO were healthy
at close.

Instrument corrections were retained as evidence rather than counted as
product failures: a foreground PostgreSQL forward caused an initial
`PoolTimedOut`; Kubernetes pod deletion exercised graceful TERM rather
than dead-owner recovery; shell-background socket witnesses died with
their parent; and the first image build hit the corporate TLS proxy.
Detached forwarding/witnesses, containerd `SIGKILL`, and the configured
internal CA/Artifactory mirror produced the discriminating runs without
weakening product security.

### Prior-head cleanup

For the prior-head Kubernetes run, the Helm release was removed,
namespace absence was verified, run-owned Screen sessions were absent,
and that source worktree remained clean. The evidence manifest was
independently recomputed and every indexed artifact passed `shasum -a
256 -c`. The current `359d8402` source worktree is also clean after the
scanner-only cleanup and push.

---------

Signed-off-by: npub122y0pqkertljmedu303rl0aqrj3w8pvu43t6jxm6875lzg6f2pwqegc3xc <5288f082d91aff2de5bc8be23fbfa01ca2e3859cac57a91b7a3fa9f12349505c@buzz.block.builderlab.xyz>
Signed-off-by: npub1dccv64krpcpse5cmkzfeh998cftungyatw3djt8jwdw6g43f7fyqzzmrf7 <6e30cd56c30e030cd31bb0939b94a7c257c9a09d5ba2d92cf2735da45629f248@buzz.block.builderlab.xyz>
Signed-off-by: Kalvin Chau <kalvin@block.xyz>
Signed-off-by: am <6e30cd56c30e030cd31bb0939b94a7c257c9a09d5ba2d92cf2735da45629f248@buzz.block.builderlab.xyz>
Signed-off-by: cid <d9f92a72922bf45c17379a47d64dae84b6020397c2d5a52b5317d512068cd9d3@buzz.block.builderlab.xyz>
Co-authored-by: npub122y0pqkertljmedu303rl0aqrj3w8pvu43t6jxm6875lzg6f2pwqegc3xc <5288f082d91aff2de5bc8be23fbfa01ca2e3859cac57a91b7a3fa9f12349505c@buzz.block.builderlab.xyz>
Co-authored-by: npub1dccv64krpcpse5cmkzfeh998cftungyatw3djt8jwdw6g43f7fyqzzmrf7 <6e30cd56c30e030cd31bb0939b94a7c257c9a09d5ba2d92cf2735da45629f248@buzz.block.builderlab.xyz>
Co-authored-by: cid <d9f92a72922bf45c17379a47d64dae84b6020397c2d5a52b5317d512068cd9d3@buzz.block.builderlab.xyz>
2026-08-12 09:25:58 -07:00

74 lines
2.4 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
//! Database error types.
use thiserror::Error;
/// Errors produced by database operations.
#[derive(Debug, Error)]
pub enum DbError {
/// A SQLx driver-level error.
#[error("database error: {0}")]
Sqlx(#[from] sqlx::Error),
/// A SQLx migration error.
#[error("migration error: {0}")]
Migrate(#[from] sqlx::migrate::MigrateError),
/// Attempted to store an AUTH event (kind 22242), which is forbidden.
#[error("AUTH events (kind 22242) must not be stored")]
AuthEventRejected,
/// Attempted to store an ephemeral event (kinds 20000–29999), which is forbidden.
#[error("ephemeral events (kind {0}) must not be stored")]
EphemeralEventRejected(u16),
/// The requested channel does not exist.
#[error("channel not found: {0}")]
ChannelNotFound(uuid::Uuid),
/// The requested member is not in the channel.
#[error("member not found in channel {0}")]
MemberNotFound(uuid::Uuid),
/// A generic not-found error.
#[error("not found: {0}")]
NotFound(String),
/// The caller lacks permission for the requested operation.
#[error("access denied: {0}")]
AccessDenied(String),
/// JSON serialization or deserialization failed.
#[error("serialization error: {0}")]
Serde(#[from] serde_json::Error),
/// A value in the database is malformed or unexpected.
#[error("invalid data: {0}")]
InvalidData(String),
/// A serving write admitted before the lifecycle transition is still live.
/// This is an ordinary retryable drain condition, not a safety violation.
#[error(
"community {community_id} still has {active_count} active serving write lease(s): {operations:?}"
)]
ServingWritesNotDrained {
/// Community whose lifecycle transition must retry.
community_id: uuid::Uuid,
/// Number of currently unexpired serving-write leases.
active_count: i64,
/// Distinct operation categories holding those leases.
operations: Vec<String>,
},
/// A deletion safety invariant is structurally violated and requires
/// operator/code remediation rather than blind retry.
#[error("deletion safety error: {0}")]
DeletionSafety(String),
/// A stored timestamp value could not be interpreted.
#[error("invalid timestamp: {0}")]
InvalidTimestamp(i64),
}
/// Convenience alias for `Result<T, DbError>`.
pub type Result<T> = std::result::Result<T, DbError>;