Implement `secrets write` command

[tegefaulkes]

Specification

As part of the #32 issue refactoring, we need to implement secrets write command. This command is the most basic method of writing secrets.

secrets read

This command needs to read the contents of a secret in a vault. The contents will be outputted to stdout. Pretty much just the existing secrets get command. I don't think any changes need to be made to it.

The command takes the form of pk secrets read [secretPath]. The output can be redirected with pk secrets read [secretPath] > some file and piping into it shouldn't do anything. (see #242 (comment))

secrets write

This command needs to update or create the contents of a file. There will be two ways to provide the secret contents here. Coompared to current implementation, this pretty much is just secrets create but allows you to update a secret as well.

1. Interactively via stdin. so if you call secrets write secretPath you can type in you contents to the terminal and send EOF (ctrl+d) to finish writing.
2. Piping data in.

In both cases the behaviour should match cat > file.

Additional context

• Related Incorporate Unix Commands to Secrets Subcommand - pk secrets * #32

Tasks

1. Implement secrets read command.
2. Implement secret write command.
3. create tests demonstrating behaviour for read.
4. create tests demonstrating behaviour for write.

[linear]

ENG-355 Implement `secrets read` and `secrets write` commands

[CMCDragonkai]

Why not just go straight to Unix commands?

[tegefaulkes]

I'm following the spec you wrote out where Imagine (IN ORDER OF PRIORITY): and read, write were top of the list. I can skip theses then since cat will basically cover that functionality anyway.

[CMCDragonkai]

The read and write commands are not normal unix commands. The historical context for this is #32 (comment) (which should be added as the specific additional context above).

I would like cat to be an alias of the read command though as it's quite a common thing for shell users to use.

[tegefaulkes]

While technically using some shell shenanigans you can use cat to both read and write files. That functionality will not work too well for PK and the vaults. We will still use cat to cover the read case here. But we still need to create a write command that will write the stdin into the secret we want.

[aryanjassal]

As discussed, the read case will be handled by the cat command, which has already been implemented into Polykey as of writing this. While write isn't standard UNIX commands, it would still need implementation.

We also wouldn't need to create a new handler for this. The edit command already has a handler which takes in a secret path, and updates the contents of the secret with the new, provided contents. However, it is a UnaryHandler. I can update that to be a ClientHandler, so it will accept streamed data instead of writing all the data in a big chunk.

[aryanjassal]

Technically, this issue is completed, as the linked PRs have correctly implemented the spec. However, we need to convert the UnaryHandler to RawHandler. I'm also not sure if we want local file system integration for this command.

Do I make another issue which continues this spec, converting to RawHandler and, if desired, implementing file system integration? Or the handler conversion issue is unrelated to this issue, and technically, the specification for this issue is done?

I need some clarification on this.

[tegefaulkes]

Using raw handlers is something we need to solve for everything at once. So we need to come up with a standard approach and apply it universally. Make a new issue for converting all the secret unix commands to using raw streaming for secret contents. Have it track everything that needs to be converted so a checklist for each command that needs to be updated. And also discuss the constraints involved for each one. For example some might just need to stream a single file such as this write command. Others needs the tar format streaming to handle a file tree or multiple files. Maybe we keep it standard across all and use the tar format for all of them? Its something that needs to be solved still.