Update Dockerfile and build scripts

These changes allow for a multi-architecture build process using `docker buildx`

These changes are suitable for Curator 6.x and 7.x

Dockerfile

@@ -1,31 +1,42 @@
 # syntax=docker/dockerfile:1
-FROM python:3.11.1-alpine3.17 as builder
+ARG PYVER=3.11.1
+ARG ALPTAG=3.17
+FROM python:${PYVER}-alpine${ALPTAG} as builder
 
 # Add the community repo for access to patchelf binary package
-RUN echo 'https://dl-cdn.alpinelinux.org/alpine/v3.17/community/' >> /etc/apk/repositories
+ARG ALPTAG
+RUN echo "https://dl-cdn.alpinelinux.org/alpine/v${ALPTAG}/community/" >> /etc/apk/repositories
 RUN apk --no-cache upgrade && apk --no-cache add build-base tar musl-utils openssl-dev patchelf
 # patchelf-wrapper is necessary now for cx_Freeze, but not for Curator itself.
 RUN pip3 install setuptools cx_Freeze patchelf-wrapper
 
 COPY . .
-RUN ln -s /lib/libc.musl-x86_64.so.1 ldd
-RUN ln -s /lib /lib64
+# alpine4docker.sh does some link magic necessary for cx_Freeze execution
+# These files are platform dependent because the architecture is in the file name.
+# This script handles it, effectively:
+# ARCH=$(uname -m)
+# ln -s /lib/libc.musl-${ARCH}.so.1 ldd
+# ln -s /lib /lib64
+RUN /bin/sh alpine4docker.sh
+
+# Install Curator locally
 RUN pip3 install .
+
+# Build (or rather Freeze) Curator
 RUN python3 setup.py build_exe
+
 # This will add the cacert.pem from certifi to the default location Curator will look
-RUN <<eot
-#!/usr/bin/env python3
-import os
-import shutil
-import certifi
-DEST = 'build/exe.linux-x86_64-3.11'
-CERT = certifi.where()
-shutil.copy(CERT, DEST)
-eot
-
-FROM alpine:3.17
+# and also move 'build/exe.{system().lower()}-{machine()}-{MAJOR}.{MINOR}' to curator_build
+RUN python3 post4docker.py
+
+### End `builder` segment
+
+### Copy frozen binary to the container that will actually be published
+ARG ALPTAG
+FROM alpine:${ALPTAG}
 RUN apk --no-cache upgrade && apk --no-cache add openssl-dev expat
-COPY --from=builder build/exe.linux-x86_64-3.11 /curator/
+# The path `curator_build` is from `builder` and `post4docker.py`
+COPY --from=builder curator_build /curator/
 RUN mkdir /.curator
 
 USER nobody:nobody

alpine4docker.sh

@@ -0,0 +1,4 @@
+ARCH=$(uname -m)
+
+ln -s /lib/libc.musl-${ARCH}.so.1 ldd
+ln -s /lib /lib64

post4docker.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+import shutil
+import certifi
+from platform import machine, system, python_version
+MAJOR, MINOR = tuple(python_version().split('.')[:-1])
+SYSTEM = system().lower()
+BUILD = f'build/exe.{system().lower()}-{machine()}-{MAJOR}.{MINOR}'
+CERT = certifi.where()
+TARGET = 'curator_build'
+
+# First copy the cert to BUILD
+shutil.copy(CERT, BUILD)
+
+# Then rename the path of BUILD itself
+shutil.move(BUILD, TARGET)