restic: support using an empty password

[michaelbeaumont]

Describe the feature you'd like to have.
It's not possible to use the empty string as the password, i.e. by setting RESTIC_PASSWORD: "" in the repository Secret for a ReplicationSource. Note restic even has --insecure-no-password.

What is the value to the end user? (why is it a priority?)
Being able to use the empty password if they don't want to take advantage of client-side encryption. For example if the local drive destination is encrypted. It avoids having to keep track of what password was used to encrypt the backups.

How will we know we have a good solution? (acceptance criteria)
When I can somehow avoid setting a password for a ReplicationSource.

[tesshuflower]

This isn't something we're planning on implementing.

[michaelbeaumont]

@tesshuflower would you accept a PR implementing it?

[tesshuflower]

@michaelbeaumont no, this isn't something we want at this time. Tell you what though, if you cat get restic to allow passing in this param as an env var, I'd consider allowing it to get passed through.

[michaelbeaumont]

There's not even really a workaround when using volsync, afaict? Even before this option existed in restic, restic users could just use an empty file as password-file. There is no such workaround with volsync, as far as I can tell, but only because of how it checks whether RESTIC_PASSWORD is set. Other restic-based tools like resticprofile have also added native support for this option.