remote-backup.sh: find a way to protect duplicity against ps

[0pdd]

The puzzle 705-eb60edc9 (from #705) in vagrant/provisioning/roles/mystamps-backup/tasks/main.yml (lines 64-64) has to be resolved: "remote-backup.sh: find a way to protect duplicity against ps"

The puzzle was created by Slava Semushin on 03-Dec-17.

Tech debt for: 57e4cc1 (#705)

[php-coder]

It seems like gpg-agent may help: https://wiki.archlinux.org/index.php/Duplicity

[php-coder]

This might get even worse: when we use su/sudo the command could that is executed is logged to system journals and might appear in some reports. Given that the command contains login and password, this might lead to a security issue.

[php-coder]

Another way to see the credential is to inspect /prod/{PID}/cmdline file.