How to run my python script on docker?

Alright, first create a specific project directory for your docker image. For example:

mkdir /home/pi/Desktop/teasr/capturing

Copy your dockerfile and script in there and change the current context to this directory.

cp /home/pi/Desktop/teasr/capturing.py /home/pi/Desktop/teasr/dockerfile /home/pi/Desktop/teasr/capturing/

cd /home/pi/Desktop/teasr/capturing

This is for best practice, as the first thing the docker-engine does on build, is read the whole current context.

Next we'll take a look at your dockerfile. It should look something like this now:

FROM python:latest

WORKDIR /usr/local/bin

COPY capturing.py .

CMD ["capturing.py", "-OPTIONAL_FLAG"]

The next thing you need to do is build it with a smart name. Using dots is generally discouraged.

docker build -t pulkit/capturing:1.0 .

Next thing is to just run the image like you've done.

docker run -ti --name capturing pulkit/capturing:1.0

The script now get executed inside the container and will probably exit upon completion.

Edit after finding the problem that created the following error:

standard_init_linux.go:195: exec user process caused "exec format error"

There's a different architecture beneath raspberry pi's (ARM instead of x86_64), which COULD'VE BEEN the problem, but wasn't. If that would've been the problem, a switch of the parent image to FROM armhf/python would've been enough.

Source

BUT! The error kept occurring.

So the solution to this problem is a simple missing Sha-Bang on top of the python script. The first line in the script needs to be #!/usr/bin/env python and that should solve the problem.

Source

You need to create a dockerfile in the directory your script is in.

You can take this template:

FROM python:latest

COPY scriptname.py /usr/local/share/

CMD ["scriptname.py", "-flag"]

Then simply execute docker build -t pulkit/scriptname:1.0 . and your image should be created.

Your image should be visible under docker images. If you want to execute it on your local computer, use docker run.

If you want it to upload to the DockerHub, you need to log into the DockerHub with docker login, then upload the image with docker push.

I Followed @samprog (most accepted) answer on my machine running on UBUNTU VERSION="14.04.6". and was getting "standard_init_linux.go:195: exec user process caused "exec format error"

None of the solution worked for me mentioned above.

Fixed the error after changing my Dockerfile as follows

FROM python:latest

COPY capturing.py ./capturing.py

CMD ["python","capturing.py"]

Note: If your script import some other module then you need to modify COPY statement in your Dockerfile as follows - COPY *.py ./

Hope this will be useful for others.

Going by question title, and if one doesn't want to create docker image but just want to run a script using standard python docker images, it can run using below command

docker run -it --rm --name my-running-script -v "$PWD":/usr/src/myapp -w /usr/src/myapp python:3.7-alpine python script_to_run.py