Ubuntu Desktop

The following defines a simple Ubuntu 22.04 space which runs a XFCE based desktop environment using the excellent KasmVNC. The home directory makes use of a volume using the hostpath CSI driver which is assumes has been configured within the nomad cluster.

Nomad-Job
job "${{.space.name}}-${{.user.username}}" {
  datacenters = ["dc1"]

  update {
    max_parallel     = 1
    min_healthy_time = "30s"
    healthy_deadline = "1m"
    auto_revert      = true
  }

  group "debian" {
    count = 1

    network {
      port "knot_port" {
        to = 3000
      }
    }

    volume "home_volume" {
      type            = "csi"
      source          = "ubuntu_${{.space.id}}_home"
      read_only       = false
      attachment_mode = "file-system"
      access_mode     = "single-node-writer"
    }

    task "debian" {
      driver = "docker"
      config {
        image = "paularlott/knot-desktop:ubuntu-22.04"

        privileged = true
        ports = ["knot_port"]
        hostname = "${{ .space.name }}"
      }

      env {
        # Define environment variables for agent
        KNOT_SERVER           = "${{.server.url}}"
        KNOT_SPACEID          = "${{.space.id}}"
        KNOT_SSH_PORT         = "22"
        KNOT_HTTP_PORT        = "80"
        KNOT_CODE_SERVER_PORT = "49374"
        KNOT_VNC_HTTP_PORT    = "5680"
        KNOT_USER             = "${{.user.username}}"

        TZ = "${{ .user.timezone }}"
      }

      volume_mount {
        volume      = "home_volume"
        destination = "/home"
      }

      resources {
        cpu = 300
        memory = 4096
      }

      # Knot Agent Port
      service {
        name = "knot-${{.space.id}}"
        port = "knot_port"

        check {
          name            = "alive"
          type            = "http"
          protocol        = "https"
          tls_skip_verify = true
          path            = "/ping"
          interval        = "10s"
          timeout         = "2s"
        }
      }
    }
  }
}

Volume-Definition
volumes:
  - id: "ubuntu_${{.space.id}}_home"
    name: "ubuntu_${{.space.id}}_home"
    plugin_id: "hostpath"
    capacity_min: 10G
    capacity_max: 10G
    mount_options:
      fs_type: "ext4"
      mount_flags:
        - rw
        - noatime
    capabilities:
      - access_mode: "single-node-writer"
        attachment_mode: "file-system"

If the namespace is set on the job e.g. to ${{.user.username}} then all the spaces would be placed into a namespace of the username, with the correct nomad configuration this would allow users to access nomad but only interact with their jobs.

The space exposes a SSH server to the agent on port 22 which can be connected to via the SSH proxy, it also exposes VSCode Server which will be available via the web interface.

The space also exposes port 80 via the web interface, assuming a web server such as Caddy or Apache is running on port 80 then it can be accessed from the spaces web interface.

Startup Scripts

During the startup of the container any scripts found in the /etc/knot-startup.d/ directory are executed as root, then any scripts in the .knot-startup.d/ directory within the users home directory are executed as the user.

This allows for both system level scripts to be started and user specific scripts.

Ubuntu Redis