Create alpine linux iso from docker - libburn permission denied - docker

Question

I have been trying to build an iso-image for alpine-linux inside a docker container following the standard instructions here however i seem to be unable to actually write the .iso back into the mounted volume due to libburn :
>>> mkimage-x86_64: Creating alpine-standard-edge-x86_64.iso
xorriso 1.4.8 : RockRidge filesystem manipulator, libburnia project.
libburn : SORRY : Failed to open device (a pseudo-drive) : Permission denied
libburn : FATAL : Burn run failed
xorriso : FATAL : -abort_on 'FAILURE' encountered 'FATAL' during image writing
libisofs: MISHAP : Image write cancelled
xorriso : FAILURE : libburn indicates failure with writing.
This is the standard result of trying to run the downloaded script from the tutorial:
sh aports/scripts/mkimage.sh --tag edge --outdir /build2/ --arch x86_64 --repository http://dl-cdn.alpinelinux.org/alpine/edge/main --profile standard
The docker image im using:
FROM alpine:latest
RUN addgroup root abuild
RUN apk add --update \
alpine-sdk \
# build-base \
apk-tools \
alpine-conf \
busybox \
git \
fakeroot \
syslinux \
xorriso \
squashfs-tools \
mtools \
dosfstools \
grub-efi \
&& rm -rf /var/cache/apk/*
COPY . /usr/src/app
WORKDIR /usr/src/app
RUN mkdir /usr/src/app/build
RUN touch /usr/src/app/build/worked.txt
RUN adduser -G abuild -g "Alpine Package Builder" -s /bin/sh -u 12345 -D builder
RUN echo "builder:newpass"|chpasswd
RUN chgrp -R abuild /usr/local; \
find /usr/local -type d | xargs chmod g+w; \
echo "builder ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/builder; \
chmod 0440 /etc/sudoers.d/builder
WORKDIR /build2/
RUN git clone git://git.alpinelinux.org/aports
RUN chmod +x aports/scripts/mkimage.sh
RUN abuild-keygen -i -a
USER builder
I have looked over the official forum however only one post mentioned something similar but did not allude to any actual resolution.
Failing to find a solution for this, can anyone else recommend a good alternative minimal distro that can be build an iso via script for x_86, x_64 and rpi?

Answer 1

You can easily create your own Alpine Linux ISO image using script alpine-make-vm-image.
Example:
sudo ./alpine-make-vm-image \
--image-format qcow2 \
--image-size 5G \
--packages "ca-certificates git ssl_client" \
--script-chroot \
alpine-$(date +%Y-%m-%d).qcow2 -- ./configure.sh

Answer 2

You're getting a permission denied error because the user you created can't access the pseudo device needed by xorriso. I removed all the user creation parts and just ran the whole thing as root and it works.
Here's the Dockerfile I used:
FROM alpine:latest
RUN apk add --no-cache \
alpine-conf \
alpine-sdk \
apk-tools \
dosfstools \
grub-efi \
mtools \
squashfs-tools \
syslinux \
xorriso
WORKDIR /src
RUN git clone git://git.alpinelinux.org/aports
RUN chmod +x aports/scripts/mkimage.sh
RUN addgroup root abuild
RUN abuild-keygen -i -a -n
WORKDIR /build
ENTRYPOINT /src/aports/scripts/mkimage.sh
CMD "--tag edge --arch x86_64 --repository http://dl-cdn.alpinelinux.org/alpine/edge/main --profile standard"
Then build and run.
docker build -t alpine-iso .
docker run -v "$(pwd):/build" -it alpine-iso