xmjiao / ams526-desktop

Docker Image for AMS 526

This Docker image provides the Ubuntu 22.04 LTS environment with X Windows for the class "AMS 526: Numerical Analysis I/Numerical Linear Algebra" at Stony Brook University. The image runs the lightweight LXDE Windows Manager, and has GCC-11, VScode, BLAS/LAPACK, valgrind, ddd, and Eigen preinstalled. The X Windows will display in your web browser in full-screen mode. You can use this Docker image on Intel or ARM-based 64-bit Linux, Mac or Windows. It allows you to use the same programming environment regardless which OS you are running on your laptop or desktop.

Preparation

Before you start, you need to first install Python and Docker on your computer by following the steps below.

Installing Python

If you use Linux or Mac, Python 3.x is most likely already installed on your computer, so you can skip this step.

If you use Windows, you need to install Python if you have not yet done so. The easiest way is to install Python 3.10 by following this link.

Installing Docker

Download Docker Desktop for free at https://docs.docker.com/get-docker/ and then run the installer. Note that you need administrator's privilege to install Docker. After installation, make sure you launch Docker before proceeding to the next step.

Notes for Windows Users

• It is highly recommended that you install Docker Desktop with the WSL 2 backend instead of the Hyper-V backend. The latter only supports Enterprise or Education versions, has lower performance, and requires additional configuration steps.

Notes for Mac Users

1. Docker Desktop supports only MacOS 10.15 or newer. The Docker image for AMS 526 supports both Intel chips and Apple M1 chips natively. Please make sure that you install Docker Desktop for Mac that is native to your computer's CPU.
2. By default, Docker uses half the number of processors and 2GB of memory on Mac. If you want to run large jobs, you can increase the amount of memory or the number of cores dedicated to Docker. Just click on the Docker icon in the system tray, select Preferences and then select the Advanced tab to adjust the settings.

Notes for Linux Users

• Most Linux distributions have a docker package. You can use the package installer for your system to install docker. Note that on some system (e.g., OpenSUSE), you may need to run the following commands to start up docker after installing docker:

sudo systemctl enable docker
sudo systemctl start docker

• After you install Docker, make sure you add yourself to the docker group. On Ubuntu, this is done by running the command:

sudo adduser $USER docker

On other systems, try the following command.

sudo usermod -G docker -a $USER

After adding yourself to the docker group, you need to log out and log back in before you can use Docker.

Running the Docker Image

To run the Docker image, first download the script ams526_desktop.py and save it to the working directory where you will store your codes and data. You can download the script using command line: On Linux or Mac, start a terminal, use the cd command to change to the working directory, and then run the following command:

curl -s -O https://raw.githubusercontent.com/xmjiao/ams526-desktop/main/ams526_desktop.py

The same process may also work in Windows PowerShell on Windows.

After downloading the script, you can start a desktop environment using the command

python3 ams526_desktop.py -p

The command will download and run the Docker image and then launch your default web browser to show the desktop environment. The -p option is optional, and it instructs the Python script to pull and update the image to the latest version.

For additional command-line options, use the command

python3 ams526_desktop.py -h

Running the Docker Image Offline

After you have download the Docker image using the curl and python commands above, you can run the image offline without internet connection using the following command:

python3 ams526_desktop.py

in the directory where you ran the curl command above.

Stopping the Docker Image

To stop the Docker image, press Ctrl-C twice in the terminal (or Windows PowerShell on Windows) on your host computer where you started the Docker image, and close the tab for the desktop in your web browser or VNC viewer.

Entering Full-Screen Mode for Desktop Environment

For the best experience, use VNC Viewer to connect to Docker image with the port and password displayed in the terminal output, which supports the full-screen mode. If you don't have the VNC viewer, you can also use the full-screen mode in a web browser.

When using a web browser, we recommend Google Chrome, Chromium browser, or Microsoft Edge, which has similar user interfaces. On Windows or Linux, you can enter full-screen mode by selecting the menu View --> "Full Screen" Alternatively, open the Chrome menu (the three vertical dots at the top right) and select the square to the far right of the Zoom buttons (the "+" and "-" buttons). To exit the full-screen mode, press the F11 key. On Mac, it behaves similarly except that the menu item is named Enter Full Screen instead of Full Screen, and the keyboard shortcut is Ctrl-Cmd-f instead of F11. You can also click on the green circle at the top-left corner of Google Chrome to enter and exit the full-screen mode. Note that in the full-screen mode, you need to disable Always Show Toolbar in Full Screen under the View menu of Google Chrome, and you can reveal the menu and the toolbar by sliding your mouse to the top of the display.

Alternatively, you can also use the "native" browsers on different platforms.

• On Windows, you can use the native browser Microsoft Edge. Toggle on and off the full-screen mode by pressing Win+Shift+Enter (hold down the Windows and Shift keys and press Enter).
• On Mac, you can use the native browser Safari, for which you can toggle the full-screen mode by clicking on the green circle at the top-left corner of Safari or selecting the View --> "Enter Full Screen" menu. To exit the full-screen mode, press Ctrl-Cmd-f, or slide your mouse to the top of the display to enable the menus.
• On Linux, the default browser Firefox does not hide its address bar in its native full-screen mode. You are recommended to use Google Chrome or Chromium browser instead. However, you can use Firefox for a full-screen viewing mode by clicking on the Fullscreen button in the left sidebar of Docker desktop environment. However, this is not recommended for day-to-day use, because Firefox would exit this full-screen mode whenever you press Esc, which may happen quite often.

If your Docker desktop environment started automatically in a non-recommended browser, you can copy and paste the URL into a recommended browser.

Tips and Tricks

1. When using the Docker desktop, the files under $HOME/.config, $HOME/.ssh, , $HOME/project, $HOME/shared and any other directory that you might have mounted explicitly are persistent. Any change to files in other directories will be lost when the Docker container stops. Use $HOME/.config to store the configuration files of the desktop environment. $HOME/shared maps to the working directory on the host, and you are recommended to use it or a mounted project directory to store codes and data.
2. The $HOME/.ssh directory in the Docker container maps to the .ssh directory on your host computer. This is particularly convenient for you to use your ssh-keys for authentications with git repositories (such as github or bitbucket). To use your ssh keys, run the ssh-add in a terminal to add your keys to the ssh-agent.
3. You can copy and paste between the host and the Docker desktop through the Clipboard box in the left toolbar, which is synced automatically with the clipboard of the Docker desktop. To copy from the Docker desktop to the host, first, select the text in the Docker desktop, and then go to the Clipboard box to copy. To copy from host to the Docker desktop, first, paste the text into the Clipboard box, and then paste the text in the Docker desktop.
4. To stop the Docker container, do not just close the browser window, because the Docker container would still be running in the background. Instead, you can stop the container using one of the following approaches:

• Use the logout button in the lower-left corner of the Docker desktop,
• Press Ctrl-C twice in the terminal where you started the python script, or
• Run the command docker stop <Container ID> in a terminal on the host, and you can find the Container ID using the docker ps -a command.