New commands, per PLAN.md 3.7:
- occ backup:key:import: adopt the master key from a recovery kit on a fresh installation
(instead of occ backup:key:init generating a new one), so occ backup:target:add opens the
existing repository on the location rather than creating an empty one.
- occ backup:restore:full: replace the database (consistent, one transaction), restore the data
directory in place, and merge config.php -- refuses up front and lists what's missing when the
Nextcloud major version or any app enabled at backup time doesn't match here (their tables must
exist before the database restore can use them), rather than guessing or partially applying.
Repository::restore() gained an optional $stripPrefix (write "data/<uid>/..." straight into the
real data directory, not a "data/" subdirectory of it) -- restoring "data/" and "config/" this way
needs no temporary copy of what can be the largest part of an instance.
occ backup:target:add now backfills the local snapshot cache (ngb_snapshots, what occ backup:list
actually reads) when it adopts an existing repository: without this, a freshly connected location
showed no restore points at all, even though the repository itself had them. One unreadable
snapshot is skipped rather than aborting the backfill or the target add itself.
Three self-referential problems found and fixed by testing this against two real, separate
Nextcloud instances sharing only the backup location (tests/integration/full-restore-roundtrip.sh
covers this; the per-process nature of these bugs meant they were invisible from inside a single
occ invocation, including the one used to write the fixes, which is exactly why a second, fresh
process re-running occ backup:status etc. was necessary to catch them):
- The full database dump includes ng_backup's own tables and appconfig rows; restoring them
verbatim would overwrite the key/target that is actively performing the restore, on THIS
installation, with the backed-up instance's. Both are now preserved: ng_backup's own tables
(and, on PostgreSQL, their sequences -- excluding a table does not exclude its sequence) are
excluded from what gets restored, and its appconfig rows are captured before the database
restore and written back after, in their own transaction.
- config.php's 'secret' is merged in from the backup (needed so already-encrypted content in the
restored database, e.g. share tokens, stays decryptable), but Target::options, the master key,
the wrapped key and the recovery kit code are all encrypted with that same instance secret
(OCP's ICrypto, or Nextcloud AppConfig's own "sensitive" flag underneath), not with ng_backup's
own key. Changing it without re-encrypting them first left all four permanently undecryptable
the moment any later occ command ran. Fixed with two helpers
(TargetService::reencryptOptionsAround(), KeyService::reencryptForSecretRotation()) that decrypt
before and re-encrypt after whatever callback actually changes the secret; config.php is applied
dead last in restoreFull(), after every other repository access. Not crash-safe (a process kill
mid-rotation would leave a key missing, not just stale) -- disaster recovery is run once by
hand, right after occ maintenance:install, a window too narrow yet to justify a two-phase write.
- A subtler variant of the same bug: Nextcloud's own AppConfig additionally encrypts a "sensitive"
value itself, tied to the same secret, underneath our own encryption. Overwriting an existing
sensitive key makes it read the old value first to compare, which then also fails against the
new secret. Deleting the key before setting the new value avoids that read entirely.
Roadmap (PLAN.md 9): phase 3 (in-place full restore, user self-service) moved out to v1.3.0; phase
2 continues toward v1.2.0 with FTP/SMB, a verification/checksum-audit command, user-export
retention, and deciding whether per-user export joins the automatic schedule.
Wires the existing RepositoryExportDestination/RepositoryImportSource (see
lib/UserMigration/) into user_migration's own UserMigrationService, resolved on demand
through a new UserMigrationServiceLocator since the app is an optional dependency
(PLAN.md 3.8) -- without it, only this feature is unavailable, the full backup still
works.
New: UserBackupService::backupUser() (occ backup:backup:user) streams a user_migration
export straight into the repository, under the same shared location lock as a regular
backup. UserRestoreService::restoreUser() (occ backup:restore:user) never imports over a
live account: --mode=replace safety-exports the current state first, then deletes and
recreates the account from the backup under the same uid; --mode=as-backup restores into
a new "<uid>-bak" account instead, since Nextcloud cannot rename a uid.
The catalog now also tracks user export manifests (Repository::recordUserExport/
listUserExports/forgetUserExport/isRecordedUserExport), rollback-protected like a
snapshot: listUserExports() verifies each one is still present on the location, and
restore only ever reads a manifest the verified catalog actually recorded, never an
arbitrary caller-supplied path. prune()'s existing raw users/ scan for blob retention is
unchanged. A new short exclusive "catalog" lock (PruneService::catalogLockKey())
serializes the catalog write itself, so two concurrent per-user backups (or one
alongside a full backup) can no longer race to write the same next generation and
silently drop one of them -- the broader per-target shared lock only ever protected
against a concurrent cleanup, not against other shared holders.
Two real bugs found by testing this against a live Nextcloud instance, not by unit
tests (RepositoryExportDestination/RepositoryImportSource implement OCP interfaces that
plain PHPUnit can't load, see tests/Unit/Repository/UserExportTest.php's docblock; the
new tests/integration/user-roundtrip.sh covers the real round trip instead):
- RepositoryImportSource::copyToFolder() double-closed the stream it handed to
putContent()/newFile() (both already close it themselves), which throws a TypeError on
PHP 8 and broke every restored file with content.
- A replace-mode restore failed on NotPermittedException: IRootFolder::getUserFolder()
caches a Folder per uid for the process lifetime, so after delete+recreate of the same
uid the import still got the deleted account's (now storage-less) folder. Fixed by
dispatching FilesystemTornDownEvent, which Root already listens for to clear exactly
that cache -- no internal OC\ classes needed.
Local review (CodeRabbit + Codex) against this diff found three more real issues, all
fixed: the catalog write race above, a failed as-backup import leaving a broken stub
account behind (now deleted on failure), and an export stream leak on a read/backend
failure in RepositoryExportDestination::copyFolder() (now closed in a finally).
Deliberately left out: wiring per-user export into the automatic backup schedule
(on-demand via occ only, for now) and retention/pruning of old user exports -- both open
design questions, not yet decided. The lease covering a single export/import still has a
fixed TTL (3600s) with no mid-call refresh, since UserMigrationService exposes no
progress; a resumable, step-based per-user backup (like the main BackupService run)
would remove that cap but is a bigger change than this pass.
Added tests/integration/targets-matrix.sh, which runs the full backup/restore
round trip through files_external's AmazonS3 and SFTP backend classes (S3
via a disposable s3mock container, SFTP via atmoz/sftp), since the existing
matrix only ever exercised the local backend.
This caught a real bug: moving a snapshot to the trash read it from the
location and streamed it straight back into a write on the same connection,
which SFTP can't do reliably (phpseclib fails to interleave a read and a
write on one connection). Backends now expose a native move() and the
id-bound snapshot object is moved with that instead of a read+write copy;
the path-bound database dump still goes through decrypt/re-encrypt, since
its AEAD authentication is tied to its path.
S3 has no bucket quota, so NG Backup enforces one: before a pack is
uploaded, the stored size plus the pack must stay under the location's
limit, otherwise the backup stops with an error (and administrators are
notified through the failed run). Repacking during prune is exempt, as it
is how space is freed. occ backup:target:limit NAME [SIZE|none].
Also ignore credential files in the repository.
Every change to the set of snapshots or trash entries writes an
encrypted catalog generation bound to the repository and its position,
with the hash of the previous generation. The server anchors the newest
generation it has seen in its app config; on open, the location must
show at least that generation and chain back to it, and every snapshot
listed must exist. A rolled-back or tampered location is refused (the
run fails and administrators are notified). Opening with the passphrase
on a new server accepts the newest valid chain.
occ backup:target:trust-current accepts a legitimately older state
(e.g. restored from the provider's snapshot) after typing the location
name; audited and announced to all administrators.
Tests: chain advances, rollback, hidden snapshot, swapped generation,
disaster recovery without anchor. Tested on NC34 by deleting the newest
catalog generation on the SFTP location.
- restore runs from the web are created under the location's exclusive
lock, like backup runs
- raw restore writes to an unpredictable temporary name opened with
exclusive create (never follows a planted symlink) and validates the
path prefix; the restore service rejects non-canonical paths instead
of trimming them (occ normalises user input before calling it)
- restore jobs report progress every minute, so a long restore is not
taken for a dead one
- README: Object Lock turns deletions into delete markers
- one locking protocol per location: backup steps and restores hold a
shared lock, prune and untrash an exclusive one and refuse while any
run (backup, restore, export) exists; starting a backup checks and
creates the run under the exclusive lock, closing the race with prune
- snapshot entries are validated when read (relative path without '.',
'..', NUL, backslash or control characters); raw restore also checks
that the resolved directory stays below the target; the restore API
and service accept canonical paths only
- recovery kit confirmation requires a recent password confirmation and
the confirmation code printed in the current kit file (new code per
kit version), proving the kit was actually downloaded
- prune decides on the authenticated index files on the location and
refreshes the local index cache from them
- restore job marks the run failed on any error; restore runs without
progress for 6 hours are failed so they cannot block cleanup forever
- tests for safe paths and a malicious snapshot path
- removed snapshots go to a trash on the location and their data is only
freed after the deletion delay, which is chosen when the key is created
(default 7 days, 1-365) and cannot be changed afterwards; any admin can
bring them back (occ backup:trash, backup:trash:restore, web UI)
- up to three passphrase slots open the same master key (like LUKS), so
one person leaving or dying does not lock the company out; slot changes
are written to every location, announced to all admins and require a
new recovery kit confirmation, while backups keep running
- occ backup:key:slots, backup:key:slot:add|replace|remove; key init takes
--label and --delete-delay-days
- web UI: deletion delay and first slot at key creation, slot management,
trash per location with restore; all behind password confirmation
- README: key, slots (safe / CTO / head of IT), and protection against
ransomware: object lock in compliance mode (e.g. 90 days), credentials
without delete rights, provider snapshots, off-site copy
- RetentionPolicy (last/daily/weekly/monthly) and PruneService: forget
snapshots the policy drops, delete packs nothing uses and repack mostly
unused ones by copying encrypted blobs as-is; new packs are indexed
before old ones are removed
- a location lock keeps prune and backups apart; append-only locations
are never pruned (cleanup via the location's lifecycle rules)
- weekly prune from the background job; occ backup:prune [--dry-run],
backup:retention, backup:target:append-only
- tests: forget+prune frees space and the remaining snapshot restores
identically, repack of mixed packs, dry-run preview, retention buckets
Opening a repository lists index/ once and downloads only index files
that are not cached; packs written by this server are cached on write,
stale cache rows are dropped. Each resumable step therefore no longer
downloads every index file from the location.
TreeWalker walks one or more roots in a stable segment-wise order with
exclusions and resumes after a cursor; ParentCursor merge-joins the
previous snapshot in the same order. BackupRun no longer keeps a file
list or the parent's entries in memory or in its state.
- migration: ngb_targets, ngb_runs, ngb_snapshots
- KeyService: master key stored encrypted with the instance secret
(unattended backups), passphrase-wrapped copy in every repository and
in the recovery kit, recorded admin confirmation per key fingerprint
- TargetService: locations built from files_external backends without a
mount; files_external is loaded through IAppManager::loadApp() and its
enabled state is left alone; credentials encrypted with ICrypto;
existing repositories are adopted only if made with this key, and a
repository cannot be registered twice
- Repository: initWithKey/openWithKey with an encrypted key check
- occ: backup:key:init|kit|confirm, backup:target:backends|add|list|remove
Dev tooling via composer (phpunit, psalm, nextcloud/ocp); vendor/ is
mounted from outside the repository by a helper script. 28 unit tests
ported from the phase-0 spikes (round trips, corruption, wrong keys,
dedup, incremental runs, partial restore, tampering, object binding,
time-boxed steps, file changed between steps).
- detect files changing during reading or between resumable steps and
re-read them (size/mtime/ctime/inode), spike F overwrites mid-run
- drop pending blob ids when a pack or index upload fails
- dump and restore PostgreSQL sequence state exactly, bound parameters,
validated catalog names; spike C checks all sequences exactly
- keep invalid UTF-8 byte-exact (tagged base64)
- refuse large tables without a primary key
- StorageBackend: check write/flush/close results, validate base path
- user_migration import/export: root paths, intermediate folders,
partial writes, read errors
- spikes: never touch an existing account, own fixtures, 512M note
BackupRun is a resumable state machine: each step works until a deadline,
uploads its pack and tree segment, and returns the state; large files are
resumed at the next blob. Snapshot is written last.
Spike F: 200 MiB file resumed across steps in separate processes; with 6
random kill -9 the run completes and restores bit-identically.
spikes/RESULTS.md summarises phase 0 and the findings for the plan.
RepositoryExportDestination / RepositoryImportSource implement the
public OCP\UserMigration interfaces on top of the repository, so
user_migration's migrators (calendar, contacts, trashbin, account,
files) export straight into the encrypted repository.
Spike E (NC34): export 0.8s, unchanged second export stores nothing;
after deleting the user, import restores account, files (bit-identical),
calendar event and contact. Findings: calendars/address books come back
as 'migrated-*' with new object URIs; importing over an existing user
duplicates contacts and adds a migrated birthday calendar; creating the
user on import needs >128 MB (password_policy word list).
ExternalStorageFactory builds storages with files_external's own
backends and auth mechanisms from an unsaved StorageConfig (as its
ConfigAdapter does), and StorageBackend adapts any IStorage to IBackend
(writeStream, seekable range reads, temp name + rename except on S3).
IBackend::put() now owns and always closes the stream, because
files_external's S3 writeStream closes it.
Spike D (NC34): S3 (SeaweedFS) and SFTP: 120 MiB backup ~6s, unchanged
run uploads nothing, restore bit-identical, no files_external mount
created, no temp files (max 12 KiB in /tmp). Works with files_external
disabled when its classes are loaded. Backup peak memory 85-89 MiB on
these targets (to investigate).
DbDumper reads every prefixed table through the Nextcloud connection in
one REPEATABLE READ (read-only) transaction, with keyset pagination on
the primary key, and streams each table as JSON lines into its own blob
stream (BlobWriter), so unchanged tables are deduplicated. Restore
replaces table contents in one transaction and resets PostgreSQL
sequences.
Spike C (NC34, PostgreSQL, standard image without pg_dump/pgsql ext):
300k-row table with bytea: dump 6.3s / 50 MiB peak, 94 MiB JSON -> 20 MiB
stored; unchanged second dump stores nothing; restore makes every table
checksum-identical and all 110 sequences continue above the maximum.
Content-addressed repository on an IBackend (local implementation):
4 MiB blobs, deflate when it helps, each blob encrypted with its id as
associated data, ~32 MiB packs with an encrypted header, one index file
per pack, snapshots as encrypted JSON lines written last.
Spike B: 390 MiB tree, peak 54 MiB; unchanged run reads nothing; a 1 MiB
change in a 300 MiB file uploads one blob; full and partial restore are
bit-identical; tampering is detected.
dillard