# Export Display with Docker

## Purpose for this guideline

This document describes the process for exporting a display from a Linux-based Docker container.

## Dockerfile

The following is a very simple Dockerifle to set up a simple test. It installs Firefox onto an Ubuntu image:

```Dockerfile
FROM ubuntu:latest
RUN apt-get update && apt-get install -y firefox
CMD ["/usr/bin/firefox"]
```

## Build the image

To build the image, run the following `docker image` command from the directory that includes the Dockerfile:

```bash
docker image build -t export_display_test .
```

## Run the container

To run the container:

```bash
docker run -it --rm -e DISPLAY=${DISPLAY} -v /tmp/.X11-unix:/tmp/.X11-unix export_display_test
```

## Result

A window should pop-up that may look like the following (it probably changes periodically, but you get the idea):

![Firefox Display](../../_static/docker_export_display.png)

If the instructions above don't work, try setting the network type to `host`.

## Explanation

The `-e` argument simply sets the `DISPLAY` variable in the container to that of the host machine. The bind mount (`-v`
argument) allows the container access to the host machine X socket.

## Useful Links

* [Official Docker documentation](https://docs.docker.com/)

*Credit: Content taken from a Confluence guide written by Steven Mueller*