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Docker Interaction

This tutorial introduces data and hardware interaction between the host system and Docker containers, including scripting, shared data, networking, and hardware access.

1. Bash Script​

Bash (Bourne Again Shell) is a scripting language used to automate tasks. It allows multiple Docker commands to be combined and executed sequentially, improving readability and reusability.

note

Using scripts helps reduce long command lines with many parameters and makes container startup easier to understand.

1.1 Basic Docker Script​

Basic template:

#!/bin/bash

docker run -it <image_name>:<tag> /bin/bash

Example script (ros_melodic.sh):

#!/bin/bash

docker run -it ros_melodic:1.0 /bin/bash

Run the script:

sh ros_melodic.sh

1.2 Run the Script​

sh ros_melodic.sh

2. Shared Data​

Docker supports sharing host resources with containers.

2.1 Shared Folder​

Mount a host directory into the container using -v.

Example:

#!/bin/bash

docker run -it -v /home/hemihex/share:/share ros_melodic:1.0 /bin/bash

This maps the host folder /home/hemihex/share to /share inside the container.

2.2 Shared Network​

Share the host network with Docker using --net=host.

#!/bin/bash

docker run -it --net=host -v /home/hemihex/share:/share ros_melodic:1.0 /bin/bash

If ifconfig is not available inside the container, install networking tools:

sudo apt install net-tools -y
ifconfig

3. Shared Hardware​

Docker containers can access host hardware devices when explicitly enabled.

3.1 Shared Graphical Interface (GUI)​

To run GUI applications inside Docker and display them on the host:

#!/bin/bash

xhost +

docker run -it --net=host -e DISPLAY=$DISPLAY -e QT_X11_NO_MITSHM=1 -v /tmp/.X11-unix:/tmp/.X11-unix -v /home/hemihex/share:/share ros_melodic:1.0 /bin/bash
warning

Using xhost + disables access control for X11. Use it only in trusted environments.

3.2 Ordinary Camera​

USB cameras can be mapped into Docker containers using /dev/video*.

If only one camera is connected, it is typically:

/dev/video0

Example:

#!/bin/bash

xhost +

docker run -it --net=host -e DISPLAY=$DISPLAY -e QT_X11_NO_MITSHM=1 -v /tmp/.X11-unix:/tmp/.X11-unix -v /home/hemihex/share:/share --device=/dev/video0 ros_melodic:1.0 /bin/bash

3.3 Depth Camera​

Depth cameras (e.g., RGB‑D cameras) often expose multiple /dev/video* devices.

To identify them:

ls /dev/video*

Map all required devices into the container:

--device=/dev/video0 --device=/dev/video1 --device=/dev/video2

Summary​

  • Bash scripts simplify Docker startup commands
  • Volumes (-v) enable host--container file sharing
  • --net=host allows shared networking
  • GUI applications require X11 forwarding
  • Hardware devices must be explicitly mapped

Maintained by HemiHex.