I am trying to build a minimal docker image, capable of nothing more but running the Python interpreter. During development I start from alpine, the final image will be build FROM scratch. I am working on a Linux Mint machine.
I am able to compile the Python compiler and install it into my current working directory like this:
cd Python-3.8.7
./configure --prefix=$PWD/../python
make install
However, I did not find out how to tweak the --prefix settings correctly so that the created shebangs will later work in the docker container.
First line of ./python/pip3 contains the absolute path of my host and reads
#!/home/orion/minimal_py_image/Python-3.8.7/../python/bin/python3.8
But it should read
#!/python/bin/python3.8
because /python is the location under which the Python interpreter will be found in the docker image.
How can I trick the make install script so that the final destination will be /python/bin?
I would like to keep the build contained in the current directory i.e. not using the folder /python on the host where I do the compilation.
Additional Information
Probably not directly relevant for this question but as reference: Here is the Dockerfile I am trying to get working:
FROM alpine
COPY python /python
COPY lib64/* /lib64/
ENV LD_LIBRARY_PATH=/usr/lib64/:/lib64/:/python/lib
ENV PATH="${PATH}:/python/bin"
I am capable of running Python already with docker run -it mini python3 -c "print('hello from python')" but pip is not working yet due-to the wrong shebang.
A common convention in Autoconf-based build systems is to support a Make variable DESTDIR. When you run make install, if DESTDIR is set, it actually installs into the configured directory under DESTDIR, but still built with the original path. You can then create an archive of the target directory, or in a Docker context, use that directory as the build context.
cd Python-3.8.7
# Use the final install target as the --prefix
./configure --prefix=/python
# Installs into e.g. ../python/python/bin/python3.8
make install DESTDIR=../python
cd ../python
tar cvzf ../python.tar.gz .
You can see this variable referenced in the Python Makefile in many places.