Docker. No such file or directory

Question

I have some files which I want to move them to a docker container. But at the end docker can't find a file..

The folder with the files on local machine are at /home/katalonne/flask4

File Structure if it matters:

The Dockerfile:

#
# First Flask App Dockerfile
#
#

# Pull base image.
FROM centos:7.0.1406

# Build commands
RUN yum install -y python-setuptools mysql-connector mysql-devel gcc python-devel
RUN easy_install pip
RUN mkdir /opt/flask4
WORKDIR /opt/flask4
ADD requirements.txt /opt/flask4
RUN pip install -r requirements.txt
ADD . /opt/flask4

# Define deafult command.
CMD ["python","hello.py"]

# Expose ports.
EXPOSE 5000

So I built the image with this command :

docker build -t flask4 .

I ran the container with volume by :

docker run -d -p 5000:5000 -v /home/Katalonne/flask4:/opt/flask4 --name web flask4

---

And when I want to run the file on the container :

docker logs -f web

I get this error that it can not find my hello.py file :

python: can't open file 'hello.py': [Errno 2] No such file or directory

What is my fault?

P.S. : I'm a Docker and Linux partially-noob.

Answer 1

The files and directories that are located in the same location as your Dockerfile are indeed available (temporarily) to your docker build. But, after the docker build, unless you have used ADD or COPY to move those files permanently to the docker container, they will not be available to your docker container after the build is done. This file context is for the build, but you want to move them to the container.

You can add the following command:

...
ADD . /opt/flask4
ADD . . 

# Define deafult command.
CMD ["python","hello.py"]

The line ADD . . should copy over all the things in your temporary build context to the container. The location that these files will go to is where your WORKDIR is pointing to (/opt/flask4).

If you only wanted to add hello.py to your container, then use

ADD hello.py hello.py

So, when you run CMD ["python","hello.py"], the pwd that you will be in is /opt/flask4, and hello.py should be in there, and running the command python hello.py in that directory should work.

HTH.