Re: [PATCH v2] Dockerfile.isar: Pull qemu-user-static from buster-backports

[Henning Schild <henning.schild@siemens.com>]

On Thu, 24 Sep 2020 13:12:35 +0200
"[ext] Jan Kiszka" <jan.kiszka@siemens.com> wrote:

> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> This is needed for running fakeroot from bullseye and sid which
> triggers an unimplemented syscall with the current version.
> 
> Due to changes in the new qemu-user-static package, the current
> approach to activate its binfmt settings no longer works. Instead,
> switch to an explicit call of the binfmt-support in init script.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> 
> Changes in v2:
>  - fix binfmt activation
>  - drop unneeded (and effectless) listing of binfmt-support for
>    buster-backports
> 
> OK, this was a nice one:
>  - debootstrap (of buster) creates the rootfs initially with a link of
>    $target/proc -> /proc
>  - later, it tries to umount $target/proc (and then sets up a proper 
>    mounting via chroot) - I consider this a bug of debootstrap

Did you report that bug or are planning to do something about it?

Henning

>  - for us, umount $target/proc, which is effectively umount /proc,
>    because /proc/sys/fs/binfmt_misc is mounted
>  - debootstrap ignores this error
>  - but due to the issue in v1, binfmt_misc wasn't mounted, and the
>    problem started...
> 
>  Dockerfile.isar | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/Dockerfile.isar b/Dockerfile.isar
> index 6b325f3..cde63b0 100644
> --- a/Dockerfile.isar
> +++ b/Dockerfile.isar
> @@ -3,7 +3,9 @@
>  FROM kasproject/kas:latest
>  
>  ENV LC_ALL=en_US.UTF-8
> -RUN apt-get update && \
> +RUN echo 'deb http://deb.debian.org/debian buster-backports main' >
> /etc/apt/sources.list.d/buster-backports.list && \
> +    echo "Package: qemu-user-static\nPin: release
> n=buster-backports\nPin-Priority: 501\n\nPackage: *\nPin: release
> n=buster-backports\nPin-Priority: -1" >
> /etc/apt/preferences.d/qemu-user-static && \
> +    apt-get update && \
>      apt-get install -y -f --no-install-recommends \
>              autoconf automake gdisk libtool bash-completion \
>              sudo grub2 grub-efi-amd64-bin grub-efi-ia32-bin \
> @@ -18,4 +20,4 @@ RUN echo "builder ALL=NOPASSWD: ALL" >
> /etc/sudoers.d/builder-nopasswd && \ RUN echo "Defaults env_keep +=
> \"ftp_proxy http_proxy https_proxy no_proxy\"" \
>      > /etc/sudoers.d/env_keep && chmod 660 /etc/sudoers.d/env_keep  
>  
> -RUN sed -i 's|#!/bin/bash|\0\n\ndpkg-reconfigure qemu-user-static
> 2>\&1 \| grep -v "already enabled in kernel"|' /kas/docker-entrypoint
> 2>+RUN sed -i 's|#!/bin/bash|\0\n\n/etc/init.d/binfmt-support start|'
> 2>/kas/docker-entrypoint