Here i provide a container which has a functioning NS3-build on Ubuntu.
This is very similar to ns3-bionic.
I have updated the script, since Ubuntu 20.04 has been released this year. So here we go again!
It can be used easily like:
docker run "NS3_IMAGE" "./waf --run hello-simulator"
Even debugging is possible:
docker run -it "NS3_IMAGE" "./waf --run=hello-simulator --command-template=\"gdb %s --args <args> \""
Modify this image or provide the source via -v to run your own simulations.