Now that age, a new tool to encrypt and decrypt files, has hit version 1.0, I’ve been trying to use it more. (I wrote a basic exploration of age a few months ago.)

I found a use-case where I often wanted to compress and encrypt a directory before uploading it to a cloud service, as a sort-of casual back-up. To make this task as simple as possible, I’m working on a tool I’m calling Bottle. I have published to GitHub a shell script version and a Rust command-line tool version.

What does it do?

Bottle (both the shell and Rust ports) allows users to compress and encrypt (and decrypt and extract) files and directories using age and tar or files using age.

The use-case is to compress and encrypt files and directories for your future self, for example to upload to an (untrusted) cloud service like Dropbox, or even to send to a friend for safe-keeping.

As simple as possible

Since age’s command-line tool is already pretty simple, I wanted to make this program as simple to use as possible.

To that end, not only is there no config, but Bottle doesn’t have any flags, options, or subcommands. Users simply point the bottle command-line tool at a file or directory and its internal logic figures out what to do.

To that end, the current version of Bottle has:

  • No flags or options.
  • Only accepts exactly one single parameter.
  • No subcommands
  • No configuration (like age)
  • No choice of what key to use. (Bottle always and only uses an age key-pair file located at ~/.bottle/bottle_key.txt.)
  • No choices about output. The output of the program is always created in the current working directory and the name is wholly based on the input file.

Usage

For specific usages, be sure to check the readme of the port of Bottle you choose, but here’s a port-agnostic summary.

  • Encrypt a file with bottle <path/to/file>
  • Compress and encrypt a directory with bottle <path/to/directory>.
  • Decrypt an age-encrypted file with bottle <path/to/file>.age
  • Decrypt and extract a .tar.gz.age file with bottle <path/to/archive>.tar.gz.age.

Users and print help information with bottle --help.

Current state of the project(s)

I worked on the shell script first. It works fine on my Ubuntu machine, but a Mac user who tried it kept hitting error messages when Bottle tried to run the complex tar commands I included in the script. (I also haven’t written that much shell, so I don’t think I ever would have gotten very confident in it.)

In an effort to make a more compatibility tool, I started from scratch in Rust. I spent a few days working on the Rust port, but, unlike the shell version, when dealing with directories, the Rust program currently reads the entire tar’d file into memory. This is obviously not ideal for working with files/directories over 1 GB or so! I’ve created an issue about this to collect notes and relevant URLs as I gear up to tackle this issue. Would love any help!

On the name

This project is not affiliated with the similarly named bitbottle project, nor are the archive file formats compatible, to my knowledge. That said, it looks much more sophisticated than my tool, so it might fit your needs better. Also, sorry about the name conflict… worried I subconsciously copied it. Open an issue if you have a suggestion for a new name for this project!

Appendix: Things I learned about writing shell scripts

Shell formatting and linting

I found a shell formatter that was very useful. I then added this to vim config file to match:

" tabs are 8 spaces for shell files
autocmd FileType sh setlocal tabstop=8
autocmd FileType sh setlocal shiftwidth=8

I also ran my script through this “spellcheck” linter, which gave me some useful tips when calling variables.

Good command for how to uninstall a binary?

I wanted to include uninstall instructions in the README of Bottle.

Taking a lead from Starship.rs’s docs, I put this command in Bottle’s README:

sh -c 'rm "$(which bottle)"'

Which I think should work well for users?