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Using Docker for Running Simulations on Various Versions of OMNeT++

Goals

It is often challenging to get models written for older versions of OMNeT++ working in contemporary Linux distributions. Older versions of OMNeT++ are often not compatible with newer Linux distibutions: changes in the C++ compiler and in the dependencies (library versions, etc.) often cause installation failure.

One solution to this problem is using Docker. We provide Docker images that contain older versions OMNeT++, already in compiled form. It is possible to compile and run the simulation models in these Docker images.

How to use the OMNeT++ Docker images

As images are published on the Docker Hub, it is straightforward to deploy OMNeT++ on any machine that has Docker.

You can see the list of the available images here: https://hub.docker.com/r/omnetpp/omnetpp/tags. Image tags have the syntax u18.04-5.5.1, where the first part is the Ubuntu version, and the second part is the OMNeT++.

After choosing the suitable image, change into the directory of the simulation model, and issue the following command (replace the end of the last argument with the proper image tag):

docker run --rm -it -v "$(pwd):/root/models" -u "$(id -u):$(id -g)" omnetpp/omnetpp:u18.04-5.5.1

This command will download the image (unless already downloaded), and opens a shell inside the container. The current working directory will be mapped to /root/models inside the Docker container. Then follow the build instructions of the simulation model (for example, type make). When the build process completes, you can run the simulation.

Note that you can only run simulation under Cmdenv and in release mode, and cannot use the IDE. The reason is that we wanted to keep the size of these Docker images relatively small. Including the IDE, debug mode libraries, the Qt libraries for Qtenv, etc. would have blown up the image size considerably.

Everything that is created under /root/models inside the Docker image, such as build artifacts and simulation result files, will be available in your local file system (in the directory where you issued the Docker command).

This setup lets edit the model files outside of the container with your favorite editor.

Further possible uses

We are internally using these Docker images for continuous testing of INET.

A future possible use case is creating and publishing reproducible simulations. The researcher who publishes the simulation would create a Docker image based on one of the OMNeT++ images, and push it to Docker Hub. The new image would contain a runnable version of the simulation. The label of the new image would be advertised, for example inside the corresponding research paper. Any researcher interested in the study would be able to pull and run the image to reproduce the results.

Alternatively, it could also be sufficient to publish the hash of the commit containing the "final" version of the model in a public Git repository, plus the tag of the OMNeT++ Docker image required for running it. This would also allow 3^rd party researchers to build and run the model in a reproducible way.