я перед switch-to-coinfugation делаю:
echo -e "nameserver
74.82.42.42\nnameserver
8.8.8.8" > /etc/resolv.conf || true
# on alicloud there is invalid server '
us2.mirrors.cloud.aliyuncs.com'
sed -i -r 's|^(deb http:)//([^/]+)/([^u].+)|\\1//
deb.debian.org/\\3|' /etc/apt/sources.list || true
sed -i -r 's|^(deb http:)//([^/]+)/(u.+)|\\1//
us.archive.ubuntu.com/\\3|' /etc/apt/sources.list || true
echo "=== install packages"
[ -f /etc/debian_version ] && (export DEBIAN_FRONTEND=noninteractive; apt-get update || true; for name in busybox psmisc cryptsetup dosfstools rsync curl xz-utils lvm2 perl libdigest-sha-perl; do dpkg-query -s $$name || apt-get install -yq --force-yes $name; done)
[ -f /etc/redhat-release ] && ( for name in cryptsetup dosfstools rsync curl xz lvm2 perl perl-Digest-SHA ; do yum install -y $name; done)