Create a temporary file with a sufficiently random name to essentially
avoid any chance of conflicts. Once the upload has finished remove the
temporary suffix. Interrupted upload thus will be ignored by restic.
This ensures that restic won't create lots of new lock files without
deleting them later on.
In some cases a Delete operation on a backend can return a "File does
not exist" error even though the Delete operation succeeded. This can
for example be caused by request retries. This caused restic to forget
about the new lock file and continue trying to remove the old (already
deleted) lock file.
The function supports efficiently loading a specified list of blobs from
a single pack in a streaming fashion. That is there's no need for
temporary files independent of the pack size.
The archiver uses FS.OpenFile, where FS is an instance of the FS
interface. This is different from fs.OpenFile, which uses the OpenFile
method provided by the fs package.
Citing Kerrisk, The Linux Programming Interface:
The O_NOATIME flag is intended for use by indexing and backup
programs. Its use can significantly reduce the amount of disk
activity, because repeated disk seeks back and forth across the
disk are not required to read the contents of a file and to update
the last access time in the file’s i-node[.]
restic used to do this, but the functionality was removed along with the
fadvise call in #670.
Currently, `restic backup` (if a `--parent` is not provided)
will choose the most recent matching snapshot as the parent snapshot.
This makes sense in the usual case,
where we tag the snapshot-being-created with the current time.
However, this doesn't make sense if the user has passed `--time`
and is currently creating a snapshot older than the latest snapshot.
Instead, choose the most recent snapshot
which is not newer than the snapshot-being-created's timestamp,
to avoid any time travel.
Impetus for this change:
I'm using restic for the first time!
I have a number of existing BTRFS snapshots
I am backing up via restic to serve as my initial set of backups.
I initially `restic backup`'d the most recent snapshot to test,
then started backing up each of the other snapshots.
I noticed in `restic cat snapshot <id>` output
that all the remaining snapshots have the most recent as the parent.
The missing eof with http2 when a response included a content-length
header but no data, has been fixed in golang 1.17.3/1.16.10. Therefore
just drop the canary test and schedule it for removal once go 1.18 is
required as minimum version by restic.
Because there is no guarantee that a cleanup of these directories will occur
after the "restic check", we extend the behavior to detect and manage these
specific cache directories and allow their cleanup too.
Package internal/dump has been reworked so its API consists of a single
type Dumper that handles tar and zip formats. Tree loading and node
writing happen concurrently.
When deleting a file, B2 sometimes returns a "500 Service Unavailable"
error but nevertheless correctly deletes the file. Due to retries in
the B2 library blazer, we sometimes also see a "400 File not present"
error. The retries of restic for the delete request then fail with
"404 File with such name does not exist.".
As we have to rely on request retries in a distributed system to handle
temporary errors, also consider a delete request to be successful if the
file is reported as not existing. This should be safe as B2 claims to
provide a strongly consistent bucket listing and thus a missing file
shouldn't mysteriously show up again later on.
restic dump uses bloblru.Cache to keep buffers alive, but also reuses
evicted buffers. That means large buffers may be used to store small
blobs, causing the cache to think it's using less memory than it
actually does.
This can be caused when the test has uploaded four blobs, then queues
two blobs for upload which are delayed. Then a seventh file can be
opened which lead to a test failure.
The rest config normally uses prepareURL to sanitize URLs and ensures
that the URL ends with a slash. However, the test used an URL without a
trailing slash, which after the rest server changes causes test
failures.
For files below 256MB this uses the md5 hash calculated while assembling
the pack file. For larger files the hash for each 100MB part is
calculated on the fly. That hash is also reused as temporary filename.
As restic only uploads encrypted data which includes among others a
random initialization vector, the file hash shouldn't be susceptible to
md5 collision attacks (even though the algorithm is broken).
This enables the backends to request the calculation of a
backend-specific hash. For the currently supported backends this will
always be MD5. The hash calculation happens as early as possible, for
pack files this is during assembly of the pack file. That way the hash
would even capture corruptions of the temporary pack file on disk.
This can be used to check how large a backup is or validate exclusions.
It does not actually write any data to the underlying backend. This is
implemented as a simple overlay backend that accepts writes without
forwarding them, passes through reads, and generally does the minimal
necessary to pretend that progress is actually happening.
Fixes #1542
Example usage:
$ restic -vv --dry-run . | grep add
new /changelog/unreleased/issue-1542, saved in 0.000s (350 B added)
modified /cmd/restic/cmd_backup.go, saved in 0.000s (16.543 KiB added)
modified /cmd/restic/global.go, saved in 0.000s (0 B added)
new /internal/backend/dry/dry_backend_test.go, saved in 0.000s (3.866 KiB added)
new /internal/backend/dry/dry_backend.go, saved in 0.000s (3.744 KiB added)
modified /internal/backend/test/tests.go, saved in 0.000s (0 B added)
modified /internal/repository/repository.go, saved in 0.000s (20.707 KiB added)
modified /internal/ui/backup.go, saved in 0.000s (9.110 KiB added)
modified /internal/ui/jsonstatus/status.go, saved in 0.001s (11.055 KiB added)
modified /restic, saved in 0.131s (25.542 MiB added)
Would add to the repo: 25.892 MiB
Add comment that the check is based on the stdlib HTTP2 client. Refactor
the checks into a function. Return an error if the value in the
Content-Length header cannot be parsed.
Ensure that only snapshots made in the past are taken into account when running restic forget with the within switches (--keep-within, --keep-within- hourly, and friends)
