Re: [PATCH v2 4/7] Shrink the rootfs substantially

[Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>]

On Mon, Apr 14, 2025 at 11:18:40AM +0100, Andrew Cooper wrote:
> bash, busybox, musl and zlib are all in the base container.
> 
> python3 and ncurses are in principle used by bits of Xen, but not in anything
> we test in CI.  argp-standlone, curl, dbus, libfdt, libgcc and sudo aren't
> used at all (for x86 at least).
> 
> libbz2 and libuuid were pulled in transitively before, and need to be included
> explicitly now.
> 
> Use apk --no-cache to avoid keeping a ~2M package index on disk.
> 
> Remove the modules scan on boot.  We don't have or build any.  This removes a
> chunk of warnings on boot.

Strictly speaking there is xen-argo.ko, but that's handled manually
anyway, so probably not worth mentioning.

> This shrinks the rootfs from ~30M down to ~8M.
> 
> No practical change.

This also adds some preparation (the case on `uname -m`) for ARM64
rootfs, would be nice to mention it too. Especially since libfdt removed
here will be re-added for ARM.

> 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>
> ---
>  scripts/alpine-rootfs.sh | 60 +++++++++++++++++++++++-----------------
>  1 file changed, 34 insertions(+), 26 deletions(-)
> 
> diff --git a/scripts/alpine-rootfs.sh b/scripts/alpine-rootfs.sh
> index 75e2f8648ce5..72c29e0a0a13 100755
> --- a/scripts/alpine-rootfs.sh
> +++ b/scripts/alpine-rootfs.sh
> @@ -4,33 +4,42 @@ set -eu
>  
>  WORKDIR="${PWD}"
>  COPYDIR="${WORKDIR}/binaries"
> +UNAME=$(uname -m)
>  
> -apk update
> +apk --no-cache update

This is no-op, no? IIUC the only thing `apk update` does is updating the
cache, which you disabled...

> -# xen runtime deps
> -apk add musl
> -apk add libgcc
> -apk add openrc
> -apk add busybox
> -apk add sudo
> -apk add dbus
> -apk add bash
> -apk add python3
> -apk add zlib
> -apk add lzo
> -apk add ncurses
> -apk add yajl
> -apk add libaio
> -apk add xz
> -apk add util-linux
> -apk add argp-standalone
> -apk add libfdt
> -apk add glib
> -apk add pixman
> -apk add curl
> -apk add udev
> -apk add pciutils
> -apk add libelf
> +PKGS=(
> +    # System
> +    openrc
> +    udev
> +    util-linux
> +
> +    # Xen toolstack runtime deps
> +    libbz2
> +    libuuid
> +    lzo
> +    xz
> +    yajl
> +
> +    # QEMU
> +    glib
> +    libaio
> +    pixman
> +    )
> +
> +case $UNAME in
> +    x86_64)
> +        PKGS+=(
> +            # System
> +            pciutils
> +
> +            # QEMU
> +            libelf
> +            )
> +        ;;
> +esac
> +
> +apk add --no-cache "${PKGS[@]}"
>  
>  # Xen
>  cd /
> @@ -45,7 +54,6 @@ rc-update add dmesg sysinit
>  rc-update add hostname boot
>  rc-update add hwclock boot
>  rc-update add hwdrivers sysinit
> -rc-update add modules boot
>  rc-update add killprocs shutdown
>  rc-update add mount-ro shutdown
>  rc-update add savecache shutdown
> -- 
> 2.39.5
> 

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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