Add pip requirements to docker image in runtime

Question

I want to be able to add some extra requirements to an own create docker image. My strategy is build the image from a dockerfile with a CMD command that will execute a \"pip ins

Answer 1

Using the concepts that @Rao and @ROMANARMY have explained in their answers, I find out finally a way of doing what I wanted: add extra python requirements to a self-created docker image.

My new Dockerfile is as follows:

FROM ubuntu:14.04

RUN apt-get update
RUN apt-get install -y python-pip python-dev build-essential 
RUN pip install --upgrade pip

WORKDIR /root

COPY install_req.sh .

CMD ["/bin/bash" , "install_req.sh"]

I've added as first command the execution of a shell script that has the following content:

#!/bin/bash
pip install -r /root/sourceCode/requirements.txt
pip freeze > /root/sourceCode/freeze.txt

And finally I build and run the image using these commands:

docker build --tag test .
docker run -itd --name container_test -v $(pwd)/sourceCode:/root/sourceCode test <- without any parameter at the end

As I explained at the beginning of the post, I have in a local folder a folder named sourceCode that contains a valid requirements.txt file with only one line "gunicorn"

So finally I've the ability of adding some extra requirements (gunicorn package in this example) to a given docker image.

After building and running my experiment If I check the logs (docker logs container_test) I see something like this:

Downloading gunicorn-19.6.0-py2.py3-none-any.whl (114kB)
    100% |################################| 122kB 1.1MB/s 
Installing collected packages: gunicorn

Furthermore, the container have created a freeze.txt file inside the mounted volume that contains all the pip packages installed, including the desired gunicorn:

chardet==2.0.1
colorama==0.2.5
gunicorn==19.6.0
html5lib==0.999
requests==2.2.1
six==1.5.2
urllib3==1.7.1

Now I've other problems with the permissions of the new created file, but that will be probably in a new post.

Thank you!