Docker tricks

Docker Tricks

Post Install, Give non-root access

sudo groupadd docker
sudo usermod -aG docker $USER
newgrp docker 

Create Image

In new folder, create necessary files and Dockerfile file such as

FROM ubuntu

# the && enforces to always update
# the -y confirms prompt messages
RUN apt-get update && apt-get install -y \
  python-pip

# local_file.py must be in the folder
COPY local_file.py /copied_file.py

# CMD defines the standard command in case `docker run` didn't specify
CMD python /copied_file.py

Build image with

# -t: name tag
docker build -t my_docker_image .

Push Image to DockerHub

First, login your shell with your DockerHub credentials via docker login.

Then tag the image with your username with docker tag <image-id> garamizo/my_docker_image. This will create a copy of the image. To find the <image-id>, call docker image list

Finally, push to cloud with docker push garamizo/my_docker_image.

Create Container

This is an example of creating a complex container.

First, install NVIDIA driver and enable NVIDIA containers.

The following command install and runs a tensorflow container with

• GPU acceleration
• Jupyter and Python3 support
• Forwarding a port for the browser access
• Loading a volume (folder from host)
• Removing container after exit

docker pull tensorflow/tensorflow:latest-gpu-py3-jupyter
docker run --gpus all \
           -u $(id -u):$(id -g) \
           --rm \
           -p 8888:8888 \
           -v $HOME/Documents/MLCourse:/tf/MLCourse \
           tensorflow/tensorflow:latest-gpu-py3-jupyter

Execute Command on Running Container

docker exec -it [container-name] [command]

• This can be executed even on containers with ENTRYPOINT.
• However, you need to specify the command even if Dockerfile has CMD.

Restart Previously-Created Container

docker start [container-name]

• This is useful when the image lacks a dependency. You can manually solve the dependency, then restart the container.
• Using this command, the ENTRYPOINT or CMD is executed in the background.

Docker for ROS

Give access to devices (cam, serial port, etc) and is within the host network:

sudo docker run -it --privileged --net=host osrf/ros:kinetic-desktop-full bash