/tmp directory is being deleted

[Nicholas Malacarne]

Hello,

The BootStack team recently ran into an issue with `juju-backup-all` on some of our clouds. In some instances, the entire `/tmp` directory is removed.

This may be due to cases where the `action_output` results are an empty string which would result in the deletion of the entire /tmp directory:

https://git.launchpad.net/juju-backup-all/tree/jujubackupall/backup.py#n84
https://git.launchpad.net/juju-backup-all/tree/jujubackupall/backup.py#n87
https://git.launchpad.net/juju-backup-all/tree/jujubackupall/backup.py#n74

Thanks.

[Garrett Neugent (thogarre)]

It looks like an old version of the snap is running where this is happening. This line looks to be the culprit line (note that it’s the parent, not the path to the file):

```python
rm_command = "sudo rm -r {}".format(filepath.parent)
```

This line has since been removed [0], but a new version the snap has not yet been built, so it hasn't been tested/rolled out anywhere yet.

In the current version of the file, the `-r` flag is still being provided, despite all the backups being individual gzip files. I've submitted MR 424592 [1] to address this.

Note that I've also updated the ownership of the snap, and created a snap recipe [2] so that new snaps will automatically be built and published to the latest/edge edge when the master branch of this repo is updated.

I'll mark this as pending review to reflect the current status.

[0] https://git.launchpad.net/juju-backup-all/commit/?id=16c68c9cfe7ce5f48313c79e4e5a90a982ab2383
[1] https://code.launchpad.net/~thogarre/juju-backup-all/+git/juju-backup-all/+merge/424592
[2] https://launchpad.net/juju-backup-all/+snaps