DIT4C Inspired RobotLab Container

A couple of days ago I posted a quick demo of how to run an old OU Windows app under wine in a Docker container that exposed the app running on a graphical desktop via a browser.

One of the the problems with that demo is that it doesn’t provide a way of uploading or downloading files, so unless the user runs the container with a volume mounted against something that does support file transfer, users couldn’t persist files outside the container.

I don’t know whether the audio works either (though I didn’t try…) but as that recipe was based on a container I’d used to run the Audacity audio editor previously, I’m guessing it should…?

Anyway… regarding the file transfer issue, I recalled putting together a container last year for my PhD student who was looking for a portable way of demoing a desktop Ruby app. Digging that out, it was easily repurposed to run RobotLab. The base container is the DIT4C X11 container. The DIT4C project lost its funding last year, I think, but the repos and Docker images still exist and they provide a really great set of examples of prebuilt containerised apps. Exactly the sort of apps I’d want on my HE Library Digital App shelf. A bit dated now, perhaps, but as I when I get a chance I’ll start trying to refresh them.

The base Dockerfile is relatively straightforward:

#Base container
FROM dit4c/dit4c-container-x11:debian

#Required in order to add backports repo
RUN apt-get update && apt-get install -y software-properties-common

# Install wine
RUN dpkg --add-architecture i386
RUN echo "deb http://httpredir.debian.org/debian jessie-backports main" | sudo tee /etc/apt/sources.list.d/docker.list
RUN apt-get update && apt-get install -y -t jessie-backports wine

# /var contains HTML site for container homepage
COPY var /var

# RobotLab windows files
COPY Apps/ /opt/Apps

# profile.d environment vars
COPY etc /etc

# Desktop shortcuts and application icons
COPY usr /usr
RUN chmod +x /usr/share/applications/robotlab.desktop
RUN chmod +x /usr/share/applications/neural.desktop
RUN chmod +x /usr/share/applications/remote.desktop

#Add items to top toolrail on desktop
RUN LNUM=$(sed -n '/launcher_item_app/=' /etc/tint2/panel.tint2rc | head -1) && \
sed -i "${LNUM}ilauncher_item_app = /usr/share/applications/robotlab.desktop" /etc/tint2/panel.tint2rc && \
sed -i "${LNUM}ilauncher_item_app = /usr/share/applications/neural.desktop" /etc/tint2/panel.tint2rc && \
sed -i "${LNUM}ilauncher_item_app = /usr/share/applications/remote.desktop" /etc/tint2/panel.tint2rc

The local build / run / push to dockerhub process is trivial:

cp Dockerfile_dit4c_x11 Dockerfile
docker build -t psychemedia/robtolab2 .
docker run -d -p 8082:8080 psychemedia/robtolab2
docker push psychemedia/robtolab2

As to what it looks like, here’s the home page:

Files can be uploaded to / downloaded from the container using the File Management link:

The Linux Desktop Session link takes you to a Linux desktop. Several tools are available in the toolbar at the top of the desktop, including a terminal and the RobotLab application.

Clicking on the RobotLab icon runs it under wine – on first run we seem to get an update message. Maybe I need to run wine as part of the start-up procedure to handle this as part of the build process?

As well as the RobotLab application, we can run other tools in the RobotLab suite, such as the Neural neural network package:

Note that I haven’t tested the student activities yet – this is still early days in just trying to work out what the tech requirements are and how the workflow / student user experience might play out…

Repo is here (it contains redundant RobotLab stuff such as drivers for the original Lego Mindstorms infra-red towers, but I haven’t yet worked out what can be dropped and what RobotLab requires…): ouseful-course-containers/ou-tm129-robotlab.

A container is also available on Dockerhub as ousefulcoursecontainers/ou-tm129-robotlab:dit4c but I haven’t had chance to check it yet… (it’s still in the build queue…).

The container can be imported into a desktop Docker environment using Kitematic:

robotlab_kitematic0

Once added, the container can also be run using Kitematic, with the user clicking on a link to take then directly to an appropriate location in their web browser:

robotlab_kitematic

The desktop / Kitematic route also enables file sharing with a local directory mounted into the container (though by the looks of it, I may need to tidy that up a little?).

The pieces are slowly starting to come together…?

Author: Tony Hirst

I'm a Senior Lecturer at The Open University, with an interest in #opendata policy and practice, as well as general web tinkering...

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