[ Docker link to existing container or image at build ]

I am trying to separate an app into an app image and a database image using 2 Dockerfiles. Both are using FROM debian:jessie as a base image. The issue that I am running into is that certain packages in the app image need to know the database location at build. Is there any way to link a build command to an existing image or container?

Specifics

My database image is an HDF5 datastore which I have successfully built.

My app image is a Python 3.5 image which installs packages for working with HDF5. The error that I am getting at build is:

Step 15 : RUN pip install tables
 ---> Running in 9ea6d6b53a19
Collecting tables
  Downloading tables-3.2.2.tar.gz (7.0MB)
    Complete output from command python setup.py egg_info:
    /usr/bin/ld: cannot find -lhdf5
    collect2: error: ld returned 1 exit status
    * Using Python 3.5.1 (default, Jan 13 2016, 18:51:24)
    * USE_PKGCONFIG: True
    .. ERROR:: Could not find a local HDF5 installation.
       You may need to explicitly state where your local HDF5 headers and
       library can be found by setting the ``HDF5_DIR`` environment
       variable or by using the ``--hdf5`` command-line option.

I think I need create an HDF5_DIR environment variable in my app Dockerfile using something like ENV HDF5_DIR path/to/hdf5/container/urs/bin/ld but I am not sure if that is correct or how to get the path to a running database container. Or if linking it to the database container is incorrect and I need to link it to the actual image (if that's even possible).

I know that HDF5 is not a common tool, but hopefully this is more of a generic issue with a generic solution. Let me know if you need to see the full Dockerfiles

Answer 1

You need to add libhdf5-dev to your docker image. I create a Dockerfile you can extend:

FROM python:3.5

RUN apt-get update
RUN apt-get -y install libhdf5-dev
RUN pip install tables