[HELP] XtermJS changing cols and rows size but linux isn't

[Gigko]

I'm facing an issue with my Linux CentOS VM - CentOS Linux release 7.9.2009 (Core), I hope you can help me.
I'm successfully connecting to my VM from a web page via web socket.

Unfortunately, cols and rows size can be changed only manually in my case via command:
[root@server/]# tput cols
80
[root@server/]# stty cols 200 rows 40
[root@server/]# tput cols
200

Are there any options to change cols and rows size dynamically ?

[jerch]

This depends on your PTY integration, most PTY libs offer a way to change the PTY size via some API call (e.g. node-pty has a resize method).

[Gigko]

In your first post you write

I'm successfully connecting to my VM from a web page via web socket.

So the question is - how did you do that?

I used websocket part from this project, https://github.com/zephinzer/cloudshell it worked well for test and debug, but when my project grew up I notice that user experience is not great because of the resizing issue.

So now I understood that I need to find a proper way to share an ssh session via websocket.

[jerch]

You cannot directly share an ssh session (or more exactly an ssh IO stream) with a websocket. You'd need to do the following (schematically):

• spawn a PTY on some linux/posix machine
• run ssh there as first process (slave side of the PTY)
• connect xtermjs to master side of the PTY (e.g. with the help of websockets or ajax/fetch long polling)

The tricky part is the PTY spawning and getting its file descriptor setup right. Normally you would not do this yourself as it is quite involved with ugly kernel/C interfaces. Thus you should look for an appropriate lib doing this for you in your backend language. There are several libs for this in rust, Go, python or for nodejs available. If you use nodejs on server side, node-pty is prolly the easiest for you to use.

[Gigko]

You cannot directly share an ssh session (or more exactly an ssh IO stream) with a websocket. You'd need to do the following (schematically):

• spawn a PTY on some linux/posix machine
• run ssh there as first process (slave side of the PTY)
• connect xtermjs to master side of the PTY (e.g. with the help of websockets or ajax/fetch long polling)

The tricky part is the PTY spawning and getting its file descriptor setup right. Normally you would not do this yourself as it is quite involved with ugly kernel/C interfaces. Thus you should look for an appropriate lib doing this for you in your backend language. There are several libs for this in rust, Go, python or for nodejs available. If you use nodejs on server side, node-pty is prolly the easiest for you to use.

Thank you!
I'll try to implement this tomorrow and I'll let you know the results.

Anyways, to run my project right, I must dig and understand how this part of my system works.

[Gigko]

I found that https://github.com/cs01/pyxtermjs
Working better with terminal resize feature