Use something other than stdin for input?

[haliphax]

I'm trying to expose a Textual App within an SSH terminal server I'm building. As such, stdin and stdout in the Python environment belong to the server, not the client connecting to the service; those are actually IO objects (asyncio Queues under the hood, I believe).

I've managed to get the client's stdout taken care of by way of a custom Driver implementation and overridden write and flush methods, but I'm not seeing anything in there that would let me do the opposite for input (e.g. read). Methods such as rich's Prompt.ask provide a way to accomplish this, so it would be wonderful if the same was true of Textual.

Since this is a single-threaded, single-process asyncio server, monkey-patching stdin is not an option. That would not only break the server's stdin, but would also not work well when multiple clients are connected simultaneously with their own, individual sessions.

[willmcgugan]

A subprocess would be the typical solution. No need to write a driver when you can launch a process and manage its stdin and stdout.

[haliphax]

Yargh. That's what I was hoping to avoid. It may be easier to do with Textual than it was with Blessed, at least.

[haliphax]

Follow-up: The description of the App.get_driver_class method implies that a Driver is used for input and output, but I don't actually see any input management aside from disable_input. Are there plans for implementing any such methods?

[haliphax]

I managed to get it to work without a subprocess by making a subclass of LinuxDriver with an overridden run_input_thread method and some other bits and bobs. I haven't tested to see if it respects the terminal type of the connecting client rather than that of the server yet, but this is very promising! I hope to summarize my approach once it's been battle tested a bit longer and post it somewhere useful.

textual.mp4

[dbieber]

Checking in if you intend to summarize and post still

[haliphax]

I haven't written up anything formal, but I can at the very least link you to the source code.

First off, here is a FileWrapper class I'm using to present a monkey-typed, file-like object to Textual: https://github.com/haliphax/xthulu/blob/c6af0ff3448621d504f0d4a17b4b1260ab77c7cd/xthulu/ssh/console/internal/file_wrapper.py

Next, here is an SSHDriver class which is derived from the LinuxDriver class in Textual (wrapping the SSHWriter object provided by asyncssh for my particular use case) where I am handling the input and output: https://github.com/haliphax/xthulu/blob/c6af0ff3448621d504f0d4a17b4b1260ab77c7cd/xthulu/ssh/console/internal/driver.py

Finally, here is my custom Console subclass that incorporates the mechanics from above: https://github.com/haliphax/xthulu/blob/c6af0ff3448621d504f0d4a17b4b1260ab77c7cd/xthulu/ssh/console/__init__.py