[Pybackpack] backup support types

[Andrew Price]

On 23/08/07 06:51, seth vidal wrote:
> <Lots of insightful use case stuff>
> So, I'm wondering if a reasonable set of goals for multiple
> backup-backends would be:
> 
> rdiff-backup: add support for specific-file restore and progress
> calculation
> 
> librsync: a generic rsync interface in pybackpack
> 
> sftp/scp: using python-paramiko to shuffle the files along
> 
> duplicity: encrypted file stores (requires more config data for this
> backup set)
> 
> Does this sound complete full of crazy? It's nearly 2am here and I admit
> that crazy has a tendency to run amuck. I was mostly thinking that by
> having a few different types to need to support to start with it would
> ensure that the abstraction layer for pybackpack is not too tied up with
> any one.

It's not totally full of crazy ;) In addition, it would help speed up CD
or DVD backups which don't require reverse diffs (perhaps it would make
disc spanning easier to implement too). I guess the way to make this
happen is to define a common interface for the different backup methods
so we could do something like, but better than:

method = gui.getbackupmethod()
try:
  method.progress_attach(somefunction) # Attach progress callback
  method.checkdest(backupset)
  method.backup(backupset)
except BadDestinationError:
  # Report bad dest
except BackupFailure:
  # Report failure

One difficulty would be how to offer a simple user interface to all
these backup options. I'm sure it's doable though, the user must know
what kind of backup destination they'll be using. So good defaults and
discoverable options is the way to go.

Enjoying this brainstorm,

--
Andy Price
http://andrewprice.me.uk