Running a simple webserver in Docker?

Question

I am trying to build a simple docker container that serves static html. I have the following Dockerfile:

FROM    ubuntu

# Install python3
RUN     apt-get update
RUN     apt-get install -y python3

# Copy html
ADD static/ /src
RUN cd /src

# Run http server on port 8080
EXPOSE  8080
CMD ["python3", "-m http.server 8080"

However when I build + run it I get the following error:

/usr/bin/python3: No module named  http

I have tried the same steps via the interactive shell and they work fine, however as soon as I use a Dockerfile it fails.

Answer 1

I think your CMD syntax is wrong. i just tried and it works fine:

FROM    ubuntu

# Install python3
RUN     apt-get update
RUN     apt-get install -y python3

# Copy html
ADD static/ /src
RUN cd /src

# Run http server on port 8080
EXPOSE  8080
CMD ["python3", "-m", "http.server", "8080"]

Answer 2

I ran into an issue with the accepted answer where network issues prevented me from running apt-get update on my corporate network..

However, the following Dockerfile worked and I believe is more lightweight than the ubuntu image for something as simple as sharing static html files.

FROM python:3.6.0-alpine
ADD static/ /src
WORKDIR /src
EXPOSE  8080
ENTRYPOINT ["python3", "-m", "http.server", "8080"]

Also, as it relates to the original question would not the following also work? I am not sure I understand the benefit of breaking the command into an array.

CMD python3 -m http.server 8080