Entire viewport is not utilised during container console attachment

[gridhead]

Bug description
Only a small part of the screen is used to display the web terminal on attachment.

Expected behavior
The web terminal should occupy the entire viewport to maximise screen utility.

Portainer Logs
Logs aren't relevant to this issue. Here's a screenshot though.

Steps to reproduce the issue:

1. Open up your Portainer instance
2. Click on the Containers section
3. Scroll down to a container of your choice and click on the terminal icon in the Quick Actions column shown in ">_".
4. Run any command or choose from the one provided in the dropdown
5. See an error

Technical details:

• Portainer version: 2.1.1
• Docker version (managed by Portainer): 20.10.3
• Kubernetes version (managed by Portainer): Not applicable
• Platform: Arch Linux ARM
• Command used to start Portainer:
  Here's an excerpt from my portainer.sh file.

  #!/bin/bash
  
  docker run -d \
      -p 8000:8000 \
      -p 9000:9000 \
      --name=portainer \
      --restart=always \
      -v /var/run/docker.sock:/var/run/docker.sock \
      -v portainer-data:/data \
      portainer/portainer-ce
  

• Browser: Mozilla Firefox 85.0.2

Additional context
Nope.

[ktalach]

Is this issue actually related to the size of inner viewport (limited to 80 chars) or external size of viewport?
The screenshot below depicts situation on my cloud (Kubernetes v1.18.10) deployment.

[gridhead]

@ktalach, the 80 character limitation is something bound to the base distribution and has no bearing with the way Portainer works. The issue that I am specifying, is about the terminal which leaves behind a significant part of the total viewport unutilized. I checked back in for v2.6.1 and the results are the same. :/

(NB - I pasted the gibberish above to make it evident that the viewport restriction inside of the terminal is an isolated case and you would want to make an new issue ticket for the same if you see it being repeated in other container instances as well)