export DISTRO_NAME=ubuntu
export DIB_RELEASE=${DIB_RELEASE:-xenial}
export DIB_DEBIAN_COMPONENTS=${DIB_DEBIAN_COMPONENTS:-main,restricted,universe}

if [ -n "${DIB_UBUNTU_DISTRIBUTION_MIRROR:-}" ]; then
    DIB_DISTRIBUTION_MIRROR=$DIB_UBUNTU_DISTRIBUTION_MIRROR
fi
export DIB_DISTRIBUTION_MIRROR=${DIB_DISTRIBUTION_MIRROR:-http://archive.ubuntu.com/ubuntu}

export DISTRO_NAME=ubuntu
export DIB_RELEASE=${DIB_RELEASE:-xenial}
export DIB_DEBIAN_COMPONENTS=${DIB_DEBIAN_COMPONENTS:-main,restricted,universe}

if [ -n "${DIB_UBUNTU_DISTRIBUTION_MIRROR:-}" ]; then
    DIB_DISTRIBUTION_MIRROR=$DIB_UBUNTU_DISTRIBUTION_MIRROR
fi

# There are two default distro mirrors depending on architecture
ARCH=${ARCH:-}
if [[ "arm64 armhf powerpc ppc64el s390x" =~ "$ARCH" ]]; then
    default_ubuntu_mirror=http://ports.ubuntu.com/ubuntu-ports
else
    default_ubuntu_mirror=http://archive.ubuntu.com/ubuntu
fi

export DIB_DISTRIBUTION_MIRROR=${DIB_DISTRIBUTION_MIRROR:-$default_ubuntu_mirror}

Use correct Ubuntu distro url on non-x86 arches
Use correct Ubuntu distro url on non-x86 arches

diskimage-builder usually provides defaults that work out of the box.
One default that does not work outside of x86 land is Ubuntu distro
mirror url. Considering there are only two valid default options, we can
automatically choose a better default.

This patch changes behavior only for architectures known to be using
http://ports.ubuntu.com/ubuntu-ports. All others still would use
http://archive.ubuntu.com/ubuntu as default. It provides some guarantee
that we do not introduce a regression.

Change-Id: If95a64bac0c88f30736da4bae7f1fdce126c0bf6
