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Kasm Workspaces Kasm Workspaces

Stack

Productivity

The Workspace Streaming Platform.Stream your workspace directly to your web browser on any device and from any location.

Configuration

Type
Compose
Platform
linux
Image
lscr.io/linuxserver/kasm:latest
Ports
63000:30007443:443
Volumes
/opt : /portainer/Files/AppData/Config/kasmworkspaces/data/profiles : /portainer/Files/AppData/Config/kasmworkspaces/profiles/dev/input : /dev/input/run/udev/data : /run/udev/data
Env vars
KASM_PORT=7443DOCKER_MTU=1500
Restart
unless-stopped
Source
Repo

Template by xneo1·Source

Standalone Install

Select an install method, to see config/commands for deploying Kasm Workspaces

Installation method

Install on Portainer

Import all app templates into your Portainer instance, for easy 1-click deploys

  1. Ensure both Docker and Portainer are installed, and up-to-date
  2. Log into your Portainer web UI
  3. Under Settings → App Templates, paste the below URL
  4. Head to Home → App Templates, and the list of apps will show up
  5. Select Kasm Workspaces, fill in any config options, and hit Deploy

Template Import URL

https://raw.githubusercontent.com/Lissy93/portainer-templates/main/templates.json
Show Me demo
Original stackfile

The compose file this template deploys, straight from its repo:

services:
  kasm:
    image: lscr.io/linuxserver/kasm:latest
    container_name: kasm
    privileged: true
    environment:
      - KASM_PORT=7443
      - DOCKER_MTU=1500 #optional
    volumes:
      - /portainer/Files/AppData/Config/kasmworkspaces/data:/opt
      - /portainer/Files/AppData/Config/kasmworkspaces/profiles:/profiles #optional
      - /dev/input:/dev/input #optional
      - /run/udev/data:/run/udev/data #optional
    ports:
      - 63000:3000
      - 7443:443
    restart: unless-stopped

Or deploy it directly from the source:

git clone https://github.com/xneo1/portainer_templates
cd portainer_templates
docker compose -f Template/Stack/kasmworkspaces.yml up -d

More install options in our documentation.

Serve Kasm Workspaces on your own domain behind Caddy, Nginx or Traefik. Fill in your domain and copy the result. It's a starting point, some apps need their own base URL or extra headers set too.

Proxying kasm-workspaces.example.com to http://kasm:3000

Add this to your Caddyfile

kasm-workspaces.example.com {
	reverse_proxy http://kasm:3000
}

Check the logs first

Nine times out of ten the logs tell you exactly what went wrong.

  • In Portainer, go to Containers, click the container, then Logs. Or run docker logs <container>
  • Exit codes help too: 137 means killed, usually out of memory. 126 or 127 means the command inside the image is broken.

Port already in use

If deployment fails with "Bind for 0.0.0.0:63000 failed: port is already allocated", something else on your server is using that port.

  • Find what's using it: sudo ss -tlnp | grep :63000
  • Stop the other service, or pick a different host port. In 63000:3000 only the left number is yours to change, the right one belongs to the app.

Running but the page won't load

The container is up but nothing appears in your browser.

  • Use your server's real IP: http://your-server-ip:63000. The 0.0.0.0 link Portainer shows isn't a real address.
  • Give it a minute after first deploy, kasm can take a while to initialise.
  • Make sure your firewall allows the port, e.g. sudo ufw allow 63000

Permission denied on volumes

If the logs show "permission denied", the app can't write to its data folder on the host.

  • Fix the ownership: sudo chown -R 1000:1000 /portainer/Files/AppData/Config/kasmworkspaces/data (and the same for the other mapped folders)

Image won't pull

Test the pull directly on the host: docker pull lscr.io/linuxserver/kasm:latest

  • "manifest unknown" means the tag no longer exists. This template uses latest, so try pinning a specific version instead.
  • "toomanyrequests" is the Docker Hub rate limit. Log in with docker login to raise it.
  • "no space left on device" means a full disk. Reclaim space with docker system prune

"exec format error"

This means the image was built for a different CPU architecture than your server.

  • Check yours with uname -m: x86_64 is amd64, aarch64 is arm64. Raspberry Pi and other ARM boards are the usual culprits.

Container keeps restarting

The unless-stopped restart policy relaunches the app after every crash, so the real error can scroll past.

  • Check the logs right after a restart, the last few lines before it died are the useful ones.
  • Get the exit code with docker inspect <container> --format '{{.State.ExitCode}}'
  • Still stuck? Redeploy once with the restart policy set to no so the failure stays visible.

Stack won't deploy

Compose stacks fail fast on small mistakes, and Portainer shows the reason just above the editor.

  • YAML only accepts spaces for indentation, a single tab breaks the whole file.

Raise an issue

Found something which isn't working as it should? Here's how to report it.

A Compose stack

Kasm Workspaces is a Compose stack, a set of containers defined in one file and brought up together by Portainer, then started and stopped as a single app.

The app image

An image is the app packed up ready to go, everything Kasm Workspaces needs bundled into one download. This template pulls lscr.io/linuxserver/kasm:latest, which Docker fetches once and then starts your own copy from.

Where the image comes from

Docker pulls its images from registries, public libraries of ready-built apps. Kasm Workspaces's comes from LinuxServer's registry, published by linuxserver.

Version tags

The bit after the colon in the image name is the version tag. Here it's latest, which always points at the newest build, so a redeploy can bump you to a newer release without you asking. Pin a specific tag if you would rather stay on one version.

Ports

A port is the door the app answers on. A mapping like 63000:3000 means it's reachable on port 63000 of your server, where the left number is yours to change and the right one belongs to the app. Once it's running, open http://your-server-ip:63000 in a browser. It opens:

  • 63000:3000, likely the web interface
  • 7443:443, likely the web interface

Volumes

A volume is where Kasm Workspaces keeps its files so they survive an update or a restart. Without one, anything it saves would sit inside the container and vanish the moment it's recreated. This template mounts:

  • /opt from /portainer/Files/AppData/Config/kasmworkspaces/data on the host
  • /profiles from /portainer/Files/AppData/Config/kasmworkspaces/profiles on the host
  • /dev/input from /dev/input on the host
  • /run/udev/data from /run/udev/data on the host

Environment variables

Environment variables are the settings you hand over when you deploy, things like a password or a timezone. Kasm Workspaces takes 2 of them, all with defaults you can leave alone or tweak:

  • KASM_PORT, defaults to 7443
  • DOCKER_MTU, defaults to 1500

Restart policy

The restart policy here is unless-stopped, so Docker restarts Kasm Workspaces after a crash or reboot, but leaves it off when you stop it on purpose. You can change this on the deploy screen. The choices are no (never restart), on-failure (only after a crash), unless-stopped (restart unless you stop it), and always (bring it back no matter what).

Networking

Nothing custom is set, so Kasm Workspaces sits on Docker's default bridge network: its own private space that reaches the outside world only through the ports it publishes.

Container name

Once it's deployed, Portainer names the container kasm. That's what you'll spot in the containers list and use in commands like docker logs kasm.

Platform

The platform is linux, the kind of system the container is built to run on. Docker and Portainer handle this on a normal Linux server.

Portainer app templates

Zooming out, this whole page comes from a Portainer app template: a short recipe telling Portainer how to set Kasm Workspaces up. Add the template list to Portainer once, then deploying Kasm Workspaces is a click rather than a wall of config.