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GNU Radio (GR) is a popular and remarkably effective framework for developing software-defined radio (SDR) applications. Nevertheless, while the framework offers a rich set of features and resources, its initial installation and setup can be overwhelming. This tutorial aims at alleviating this problem by leveraging a reproducible Docker-based environment.

The main goal of the setup explained in the sequel is to separate the roles of the host and the Docker container. It is usually preferable to edit the GR sources directly from the host on an editor of choice. Hence, the adopted setup ensures the host controls the GR sources. On the other hand, one usually wants to avoid installing dependencies and GR itself on the host filesystem. This is where the container environment comes in. In the setup that follows, you will use the container environment to compile GR, install it, and install all software dependencies. Ultimately, this arrangement preserves the host in a clean state.

Before proceeding, note this tutorial was developed and tested on a macOS Big Sur environment, using Docker Desktop (M1 build) v3.3.0. However, it can easily be adapted to other platforms.

To start, clone the project as follows:

git clone  https://github.com/igorauad/gnuradio-docker-env

Next, clone GR inside the gnuradio-docker-env directory:

cd gnuradio-docker-env/
git clone https://github.com/gnuradio/gnuradio.git

This GR directory is meant to be your working directory for GR development.

GUI Configuration

Next, prepare to run GUI applications inside the container (e.g., to run gnuradio-companion). Note there will be no X Server running in the container. Hence, the container will need to use the host’s X Server.

For example, on macOS, you can use the XQuartz application on the host to display GUI applications running inside the container. To do so, first, you need to define the DISPLAY env var on the running container such that it points to the host’s X server. You can test whether this works by running a GUI-based image such as xeyes. For example, run the following:

docker run -e DISPLAY=host.docker.internal:0 gns3/xeyes

At this point, you will likely see Error: Can't open display. That’s because you still need to authorize the container to access the host’s X server. To do so, check the source IP address of the X11 packets coming from the container. Open a terminal window and run:

sudo tcpdump -i any port 6000

Then, on another window, run the xeyes container and observe the packets on tcpdump. You should see packets coming from an IP address in the same subnet of the Docker bridge network.

For example, let’s say the source IP address is 192.168.64.2. Then, you can authorize this IP address to access the X server by running:

xhost + 192.168.64.2

Note: xhost provides a simple way to grant access to your host’s X server. However, it is not the safest approach. If you are worried about security, you can implement the X server access using xauth instead.

Now, rerun xeyes. It should open the GUI successfully.

If the GUI still fails, make sure that:

  1. XQuartz (on macOS) is configured to allow connections from network clients (at Preferences > Security).

  2. The container can ping the host. On Docker Mac, you can test with ping host.docker.internal.

Launching

Next, build and launch the container in detached mode:

docker-compose up --build -d

NOTE: change the DISPLAY variable on docker-compose.yml if you are not running on Docker Mac.

This compose stack creates three volumes:

  1. gr_prefix: a named volume where GR will be installed.
  2. gr_build: a named volume containing the GR build directory.
  3. A bind mount of the gnuradio directory cloned earlier.

The latter (the bind mount volume) allows for editing the GR sources directly from the host. Any changes made to the gnuradio/ directory are reflected inside the container. Likewise, any changes made to the sources inside the container (e.g., output products from gr_modtool) are synchronized back to the host.

In contrast, the first two volumes (the named volumes) are not tied to a host directory. Instead, they are isolated on purpose. For example, the gr_build volume will hold the GR build directory such that only the container can access it, while the host does not see the build directory. This approach is meant to preserve the state of the host’s gnuradio directory as clean as possible.

Next, launch an interactive bash session on the running container:

docker exec -it gnuradio-docker-env_gnuradio_1 bash

Finally, compile GR inside the container:

cd src/gnuradio/build/
cmake \
	-DCMAKE_INSTALL_PREFIX=/root/gr_prefix/ \
	-DCMAKE_BUILD_TYPE=Debug \
	-DENABLE_GR_AUDIO=OFF \
	-DENABLE_GR_TRELLIS=OFF \
	-DENABLE_GR_VIDEO_SDL=OFF \
	-DENABLE_GR_VOCODER=OFF \
	-DENABLE_GR_WAVELET=OFF \
	-DENABLE_GR_ZEROMQ=OFF \
	../
make -j`nproc`
make test
make install
ldconfig

Note: you may need to adjust the Docker resources. On macOS, access Docker Desktop > Preferences > Resources.

The given steps will install GR on the gr_prefix named volume mentioned earlier. Hence, the installation will persist across container sessions. That is, you can stop the container any time and resume later.

Furthermore, the build directory will be preserved on the gr_build volume. Thus, after the first compilation, you can make incremental changes to the sources without recompiling the whole project tree.

At this point, you should be ready to run and develop with GR. For example, try launching gnuradio-companion:

gnuradio-companion

OOT Development

If you would like to develop an out-of-tree (OOT) GR module using the same environment, you can do so by proceeding with the following steps:

  1. Clone your OOT module in the root directory of this project, just like how gnuradio was cloned.
  2. Modify the Dockerfile container image recipe such that it installs the dependencies required for your OOT module.
  3. Add the appropriate volumes on docker-compose.yml. For example, if you are developing an OOT module named gr-oot, add the following to services:gnuradio:volumes and volumes:
services:
    gnuradio:
        ...
        volumes:
            ...
            - ./gr-oot/:/root/gr_prefix/src/gr-oot/
            - gr_oot_build:/root/gr_prefix/src/gr-oot/build/

volumes:
  ...
  gr_oot_build
  1. Build and install the OOT module from the build directory at src/gr-oot/build/ inside the container.

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