Add some documentation

Dockerfile

@@ -1,10 +1,15 @@
+# First build arg is to ensure pulling the image from the correct repository
+# The following will work with any library image that supports multi-arch
+# Other repositories may use tag suffix instead
 ARG REPO=library
 FROM ${REPO}/python:3-alpine
 
+# This should be the target qemu arch
 ARG ARCH=x86_64
-
 COPY ./build/qemu-${ARCH}-static /usr/bin/
 
+# Everything below here is just a simple example
+
 RUN echo "OK" > /foo
 
 CMD [ "cat", "/foo" ]

Readme.md

@@ -0,0 +1,5 @@
+# multiarch-pipeline-test
+
+This is a test repo that serves as an example of publishing multi-arch Docker builds with Drone.
+
+Some comments exist inline in the included files and more robust documentation is forthcoming.

get_qemu.sh

@@ -6,6 +6,7 @@ VERSION=v2.9.1-1
 mkdir -p build
 cd build
 
+# Multiple args can be passed in, but in most cases (Makefile and .drone.yml) we only use one at a time
 for target_arch in $*; do
   wget -N https://github.com/multiarch/qemu-user-static/releases/download/$VERSION/${HOST_ARCH}_qemu-${target_arch}-static.tar.gz
   tar -xvf ${HOST_ARCH}_qemu-${target_arch}-static.tar.gz