Add a copy command to copy snapshots between repositories. It allows the user
to specify a destination repository, password, password-file, password-command
or key-hint to supply the necessary details to open the destination repository.
You need to supply a list of snapshots to copy, snapshots which already exist
in the destination repository will be skipped.
Note, when using the network this becomes rather slow, as it needs to read the
blocks, decrypt them using the source key, then encrypt them again using the
destination key before finally writing them out to the destination repository.
The backup command used to return a zero exit code as long as a snapshot
could be created successfully, even if some of the source files could not
be read (in which case the snapshot would contain the rest of the files).
This made it hard for automation/scripts to detect failures/incomplete
backups by looking at the exit code. Restic now returns the following exit
codes for the backup command:
- 0 when the command was successful
- 1 when there was a fatal error (no snapshot created)
- 3 when some source data could not be read (incomplete snapshot created)
By default (i.e., without profile.NoShutdownHook), profile.Start listens
for SIGINT and will stop the profile and call os.Exit(0).
restic already listens for SIGINT and runs its own cleanup handlers
before calling os.Exit(0).
As is, these handlers are racing when an interrupt occurs, and in my
experience, restic tends to win the race, resulting in an unusable
profile.
Eliminate the race and properly stop profiles on interrupt by disabling
package profile's signal handler and instead stop the profile in a
restic cleanup handler.
Instead of determining the password lazily during ReadPassword(), do so now in
cobra.PersistentPreRunE() so we can store the result in the globalOptions and
reuse/override when applicable without having to worry about the environment
or flag options interfering.
