update.sh

#!/bin/bash -xe

# A POSIX variable
OPTIND=1 # Reset in case getopts has been used previously in the shell.

while getopts "a:v:q:u:d:t:" opt; do
    case "$opt" in
    a)  ARCH=$OPTARG
        ;;
    v)  VERSION=$OPTARG
        ;;
    q)  QEMU_ARCH=$OPTARG
        ;;
    u)  QEMU_VER=$OPTARG
        ;;
    d)  DOCKER_REPO=$OPTARG
        ;;
    t)  TAG_ARCH=$OPTARG
        ;;
    esac
done

mysha256sum=sha256sum
if which gsha256sum &> /dev/null; then
    mysha256sum=gsha256sum
fi
wget_common_opts="-t 3 -w 1 --retry-connrefused --no-dns-cache --retry-on-http-error=403"
wget_opts="${wget_common_opts} -N"
wget_spider_opts="${wget_common_opts} --spider"

function wget_and_sleep() {
    wget ${@}
    return_code=${?}
    sleep 1
    return ${return_code}
}

(
rootTar="Fedora-Container-Root-${VERSION}.${ARCH}.tar"
# Use a real server dl.fedoraproject.org
# instead of a balancing server download.fedoraproject.org
# to avoid redirected to an invalid mirror server that causes http status 404.
# baseUrl="https://download.fedoraproject.org/pub"
baseUrl="https://dl.fedoraproject.org/pub"
archiveBaseUrl="https://archives.fedoraproject.org/pub/archive"
if wget_and_sleep ${wget_spider_opts} "$baseUrl/fedora-secondary/releases/${VERSION}/Container/${ARCH}/images"; then
    baseUrl+="/fedora-secondary/releases/${VERSION}/Container/${ARCH}/images"
elif wget_and_sleep ${wget_spider_opts} "$baseUrl/fedora/linux/releases/${VERSION}/Container/${ARCH}/images"; then
    baseUrl+="/fedora/linux/releases/${VERSION}/Container/${ARCH}/images"
elif wget_and_sleep ${wget_spider_opts} "$archiveBaseUrl/fedora/linux/releases/${VERSION}/Container/${ARCH}/images"; then
    baseUrl="${archiveBaseUrl}/fedora/linux/releases/${VERSION}/Container/${ARCH}/images"
else
    echo >&2 "error: Unable to find correct base url"
    exit 1
fi

for update in {0..15}; do
    # 30-s390x only has the Minimal-Base image.
    for base in Base Minimal-Base; do
        if wget_and_sleep ${wget_spider_opts} "$baseUrl/Fedora-Container-${base}-${VERSION}-1.$update.${ARCH}.tar.xz"; then
            fullTar="Fedora-Container-${base}-${VERSION}-1.$update.${ARCH}.tar.xz"
            checksum="Fedora-Container-${VERSION}-1.$update-${ARCH}-CHECKSUM"
            break 2
        fi
    done
done

if [ -z "$fullTar" ]; then
    echo >&2 "error: Unable to find correct update"
    exit 1
fi

mkdir -p ../.temp/$fullTar.temp
pushd ../.temp
wget_and_sleep ${wget_opts} "$baseUrl/$checksum" || true
wget_and_sleep ${wget_opts} "$baseUrl/$fullTar"
if [ -f $checksum ]; then
    # Set ignore-missing to Ignore Fedora-Container-Minimal-Base-*.tar.gz
    # in the checksum file.
    if ! $mysha256sum --status -c --ignore-missing $checksum; then
        echo >&2 "error: '$fullTar' has invalid SHA256"
        exit 1
    fi
fi
popd
tar -C ../.temp/$fullTar.temp -xf "../.temp/$fullTar"
mv -f ../.temp/$fullTar.temp/*/layer.tar $rootTar
rm -rf ../.temp/$fullTar.temp
cat > Dockerfile <<EOF
FROM scratch
ADD $rootTar /

ENV ARCH=${ARCH} FEDORA_SUITE=${VERSION} DOCKER_REPO=${DOCKER_REPO}
EOF

if [ -n "${QEMU_ARCH}" ]; then
    if [ ! -f x86_64_qemu-${QEMU_ARCH}-static.tar.gz ]; then
        wget_and_sleep ${wget_opts} https://github.com/multiarch/qemu-user-static/releases/download/${QEMU_VER}/x86_64_qemu-${QEMU_ARCH}-static.tar.gz
    fi
    cat >> Dockerfile <<EOF

# Add qemu-user-static binary for amd64 builders
ADD x86_64_qemu-${QEMU_ARCH}-static.tar.gz /usr/bin
EOF
fi

cat >> Dockerfile <<EOF

# overwrite this with 'CMD []' in a dependent Dockerfile
CMD ["/bin/bash"]
EOF
)

docker build -t "${DOCKER_REPO}:${VERSION}-${TAG_ARCH}" .
docker run --rm "${DOCKER_REPO}:${VERSION}-${TAG_ARCH}" /bin/bash -ec "
    uname -a
    echo
    cat /etc/os-release 2>/dev/null
    echo
    cat /etc/redhat-release 2>/dev/null
    true
"