How Awesome is Docker?

Fully configured Ubuntu server up and running in minutes? On Windows? Impossible you say? It is not!

Start by installing Docker. We will try to run the following Python code in the Docker container.

try:
    from slackclient import SlackClient
    #import os # we need this for the next line
    # print the environment variable we exported in Dockerfile
    print(os.environ.get('SOME_TOKEN'))
except Exception as e:
    print("Error when importing 'SlackClient'")
    print(repr(e))
else:
    print("Succes!!!'")    
finally:
    pass

Copy this snippet to a file and name it somecode.py. Create a file called Dockerfile and paste the following into it.

FROM ubuntu:latest
# update apt-get then install python3.5 and pip3
RUN apt-get -y update && apt-get install -y python3.5 && apt-get install -y python3-pip
# update pip3
RUN pip3 install --upgrade pip
# install python modulesslackclient
RUN pip3 install slackclient==1.0.0
# copy source files
COPY somecode.py /src/somecode.py
# export some tokens
ENV SOME_TOKEN='this is a token'
# run the bot
CMD ["python3.5", "/src/somecode.py"]

Then run these few lines of PowerShell.

cd $PSScriptRoot
# build the image (based on 'Dockerfile' in this folder) - ignore the security warning
docker build -t codebeaver/dockerisawesome --force-rm .
# run a container using the image we just created, --rm means we remove the container after it exists
docker run --rm codebeaver/dockerisawesome

It may take some time to download the Ubuntu base image (ca. 500mb).

I intentionally put in an error. We did not import the os library in the Python code. Uncomment import os and run the PowerShell code again. That was it. You can easily install additional Python libraries by editing the Dockerfile.

You can run the container in Azure and there are various services for running Docker containers for you.