Re: [PATCH 1/3] Rework rootfs generation to make a cpio archive

[Frediano Ziglio <frediano.ziglio@xxxxxxxxx>]

On Fri, Apr 11, 2025 at 11:52 AM Andrew Cooper
<andrew.cooper3@xxxxxxxxxx> wrote:
>
> Rename the script as we're going to use it for ARM64 shortly, and have it take
> a tar or cpio parameter to determine the output format.
>
> Turn it into a proper bash script, and provide the cpio form under the new
> artefact naming scheme.
>
> No functional change.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> ---
> CC: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> CC: Michal Orzel <michal.orzel@xxxxxxx>
> CC: Doug Goldstein <cardoe@xxxxxxxxxx>
> CC: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
> ---
>  .gitlab-ci.yml                                |  9 +++++++-
>  ...6_64-rootfs-alpine.sh => alpine-rootfs.sh} | 21 +++++++++++++++++--
>  2 files changed, 27 insertions(+), 3 deletions(-)
>  rename scripts/{x86_64-rootfs-alpine.sh => alpine-rootfs.sh} (75%)
>
> diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
> index 1d2c72b268a3..916c5ae9d508 100644
> --- a/.gitlab-ci.yml
> +++ b/.gitlab-ci.yml
> @@ -42,6 +42,13 @@ linux-6.6.86-arm64:
>  #
>  # x86_64 artifacts
>  #
> +alpine-3.18-x86_64-rootfs:
> +  extends: .x86_64-artifacts
> +  script:
> +    - ./scripts/alpine-rootfs.sh cpio
> +  variables:
> +    CONTAINER: alpine:3.18-x86_64-base
> +
>  linux-6.6.56-x86_64:
>    extends: .x86_64-artifacts
>    script: ./scripts/build-linux.sh
> @@ -62,7 +69,7 @@ x86_64-kernel-linux-6.6.56:
>  x86_64-rootfs-alpine-3.18:
>    extends: .x86_64-artifacts
>    script:
> -    - . scripts/x86_64-rootfs-alpine.sh
> +    - ./scripts/alpine-rootfs.sh tar
>    variables:
>      CONTAINER: alpine:3.18-x86_64-base
>
> diff --git a/scripts/x86_64-rootfs-alpine.sh b/scripts/alpine-rootfs.sh
> similarity index 75%
> rename from scripts/x86_64-rootfs-alpine.sh
> rename to scripts/alpine-rootfs.sh
> index b70b3a54ede5..c29c92d1c682 100755
> --- a/scripts/x86_64-rootfs-alpine.sh
> +++ b/scripts/alpine-rootfs.sh
> @@ -1,4 +1,9 @@
> +#!/bin/bash
> +
> +set -eu
> +
>  WORKDIR="${PWD}"
> +COPYDIR="${WORKDIR}/binaries"
>
>  apk update
>
> @@ -56,5 +61,17 @@ passwd -d "root" root
>
>  # Create rootfs
>  cd /
> -tar cvzf "${WORKDIR}/binaries/initrd.tar.gz" \
> -    bin dev etc home init lib mnt opt root sbin usr var
> +PATHS="bin dev etc home init lib mnt opt root sbin usr var"
> +
> +case $1 in
> +    cpio)
> +        find $PATHS | cpio -o -H newc | gzip > "${COPYDIR}/rootfs.cpio.gz"
> +

Paranoia mode: -print0 for find and -0 for cpio to support weird file names?

> +        # Print the contents for the build log
> +        zcat "${COPYDIR}/rootfs.cpio.gz" | cpio -tv

I saw other comments about -v and busybox compatibility.
I suppose it depends how important are performances here, otherwise I
could suggest the usage of mkfifo before, use -F option to the fifo
and use an additional pipeline to compress the file.

mypipe=$(mktemp -u)
mkfifo $mypipe
gzip -c > "${COPYDIR}/rootfs.cpio.gz" < $mypipe &
find $PATHS -print0 | cpio -o -H newc -F $mypipe -0
wait # for gzip
rm $mypipe

> +        ;;
> +
> +    tar)
> +        tar cvzf "${COPYDIR}/initrd.tar.gz" $PATHS
> +        ;;
> +esac
> --
> 2.39.5
>
>

Frediano