RHCOS Minimal FS Automation

create-rhcos-fs.sh

#!/usr/bin/env bash

# set -euo pipefail

die () {
    echo >&2 "$@"
    exit 1
}

[ "$#" -eq 1 ] || die "Exactly one argument required: target RHCOS version, e.g. '4.12'. $# provided."


SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd)"
TMPDIR=$(mktemp -d)
IMG_FILENAME="rhcos-live-rootfs.x86_64.img"
IMG_PATH="$TMPDIR/$IMG_FILENAME"

function download_fs {
    TARGET_IMAGE="https://mirror.openshift.com/pub/openshift-v4/dependencies/rhcos/"$1"/latest/rhcos-live-rootfs.x86_64.img"
    echo "Downloading image from $TARGET_IMAGE" 
    curl "$TARGET_IMAGE" -o "$IMG_PATH"
}

function unpack_image {
    cpio -idv < "$IMG_FILENAME"
    unsquashfs -no-xattrs -f -d sqfs root.squashfs
}

function copy_contents {
    TARGET="$SCRIPT_DIR/../testdata/NodeScanning/rhcos/$1"
    echo "Copying needed filed to $TARGET"
    mkdir -p "$TARGET/usr/lib"
    mkdir -p "$TARGET/usr/share"
    mkdir -p "$TARGET/etc"
    cp "$ROOTFS_PATH/usr/lib/system-release" "$TARGET/usr/lib/system-release"
    ln -s "../usr/lib/system-release" "$TARGET/etc/system-release"
    cp "$ROOTFS_PATH/etc/os-release" "$TARGET/etc/os-release"
    cp -R "$ROOTFS_PATH/usr/share/rpm" "$TARGET/usr/share/rpm"
    cp -R "$ROOTFS_PATH/usr/share/buildinfo" "$TARGET/usr/share/buildinfo"
}

echo "Script called from $SCRIPT_DIR"
echo "Set workdir to $TMPDIR"
cd $TMPDIR

echo "Downloading live image..."
download_fs "$1"

echo "Unpacking image..."
unpack_image

ROOTFS_PATH=$(find sqfs/ostree/deploy/rhcos/deploy -name run -exec dirname {} \;)
echo "Found base path for RHCOS root fs at $ROOTFS_PATH"

echo "Collecting needed files..."
copy_contents "$1"

echo "Cleaning up tmp folder..."
trap 'rm -rf -- "$TMPDIR"' EXIT