[Duplicity-talk] SSH backend and shell escaping

[Yves Goergen]

I have a problem with shell escaping now. There's too many quotes 
somewhere and I don't know who doesn't do it right. Here's the essence 
of my backup script. Some of these values come from a shared 
configuration file somewhere else, so they need to be structured like this.

> SFTP_HOST=xxxx.de
> SFTP_USER=xxxx
> SFTP_KEYFILE=/root/.ssh/id_backup
> BACKUP_NAME=test
> KEY_ID=ABCDEF12
>
> COMMON_ARGS="--archive-dir /backup 
> --ssh-options=\"-oIdentityFile=$SFTP_KEYFILE\""
> COMMON_BACKUP_ARGS="$COMMON_ARGS --name $BACKUP_NAME --encrypt-sign-key $KEY_ID"
>
> SOURCE=/tmp
> DEST=sftp://address@hidden/backup-$BACKUP_NAME
>
> export PASSPHRASE=
>
> duplicity $COMMON_BACKUP_ARGS $FULL_EVERY_DAYS "$SOURCE" "$DEST"

The result is this:

BackendException: ssh connection to address@hidden:22 failed: [Errno 2] No 
such file or directory: '/root/.ssh/id_backup"'

Note the extra " at the end of the SSH key file name. It's not supposed 
to be there. Is duplicity not parsing shell arguments right? If I 
specify the --ssh-options argument directly with the duplicity call, not 
inside a variable, it works fine. So my setup is basically correct. This 
change where I want that parameter for all different duplicity calls 
just can't be parsed.

I know that in this case I might just leave out the nested quotes. But 
as soon as I need a second SSH option, it's mandatory.

My shell is bash on Ubuntu 14.04. Duplicity 0.6.23.

--
Yves Goergen
http://unclassified.de
http://dev.unclassified.de