An Alpine environment is required to build an Alpine Docker image. An Alpine WSL setup under Windows can be used or run an Alpine Docker image from hub.docker.com.
docker run -it alpine:3.10 /bin/sh
Run the following commands in your Alpine environment (as root user):
# apk add alpine-sdk linux-headers libcap-dev alpine-make-rootfs
# addgroup root abuild
# abuild-keygen -a -i
Note that you must be in the abuild group to build the apk packages, so you may need to open a new root shell:
# sudo su -
The Alpine Docker image requires downloading the alpine-keys, musl, busybox, alpine-baselayout, ca-certificates, pax-utils, apk-tools, libtls-standalone, openssl and zlib aports packages. To build a local copy of each package:
# mkdir apk source
# for i in alpine-keys musl busybox alpine-baselayout ca-certificates pax-utils \
apk-tools libtls-standalone openssl zlib; \
do \
(cd $i; abuild -P ~/apk -s ~/source -R -F); \
done
To create the Docker image:
APK_OPTS=~/source alpine-make-rootfs --branch v3.10.3 --packages "apk-tools alpine-keys" -- - | docker import -c 'CMD /bin/sh' - alpine:3.10.3