The one-time data move decentralization needs (issue 0003c): copy the
entire control-plane state from the local SQLite database into the
replicated JetStream KV buckets, with a backup taken first.
pkg/membership:
- Snapshot / SealedKeyRecord: a backend-agnostic dump of the whole
control plane (rooms with their real epoch, members, every sealed-key
row across epochs, users with status).
- (*sqliteStore).ExportSnapshot and (*jetstreamStore).ExportSnapshot read
a full Snapshot from each backend; (*jetstreamStore).importSnapshot
writes one with raw Puts (preserving epoch/status, not resetting to
defaults) so the migration is faithful and idempotent (every write is
an overwrite, so re-running converges).
- MigrateSQLiteToKV orchestrates export -> import; BackupSQLite makes a
consistent copy via SQLite's VACUUM INTO before any migration.
cmd/membershipd:
- `membershipd migrate-to-kv --db <path> --nats-url <url> [--replicas N]
[--ca <cert>] [--no-backup]` backs up the SQLite file, connects to the
cluster's NATS, and migrates. Dispatched on the host like `user`.
Tests (DoD: golden + edge + parity):
- TestMigrateSQLiteToKVParity: seed a representative SQLite (two rooms,
one rekeyed to epoch 2, members, a revoked user); after migration the
KV ExportSnapshot equals the SQLite ExportSnapshot.
- TestMigrateSQLiteToKVIdempotent: running the migration twice yields the
same KV state.
- TestBackupSQLiteCreatesConsistentCopy: the backup reopens with
identical data.
Plus a binary smoke (seed user -> run server -> migrate-to-kv -> re-run):
backup written, 1 user migrated, second run identical.