diff --git a/diskimage_builder/elements/ubuntu/pre-install.d/01-set-ubuntu-mirror b/diskimage_builder/elements/ubuntu/pre-install.d/01-set-ubuntu-mirror index efde2784d..5b4bb18b8 100755 --- a/diskimage_builder/elements/ubuntu/pre-install.d/01-set-ubuntu-mirror +++ b/diskimage_builder/elements/ubuntu/pre-install.d/01-set-ubuntu-mirror @@ -1,6 +1,6 @@ #!/bin/bash -if [ ${DIB_DEBUG_TRACE:-0} -gt 1 ]; then +if [[ ${DIB_DEBUG_TRACE:-0} -gt 1 ]]; then set -x fi set -eu @@ -8,11 +8,11 @@ set -o pipefail DIB_DISTRIBUTION_MIRROR=${DIB_DISTRIBUTION_MIRROR:-} -[ -n "$DIB_DISTRIBUTION_MIRROR" ] || exit 0 +[[ -n "$DIB_DISTRIBUTION_MIRROR" ]] || exit 0 while IFS= read line do - if [[ "$line" =~ ${DIB_DISTRIBUTION_MIRROR_UBUNTU_IGNORE:-} ]]; then + if [[ -n "${DIB_DISTRIBUTION_MIRROR_UBUNTU_IGNORE:-}" && "$line" =~ ${DIB_DISTRIBUTION_MIRROR_UBUNTU_IGNORE:-} ]]; then # append line unmodified echo "$line" | tee --append /etc/apt/sources.list.new else