build-initramfs.sh: support CentOS-7 again

1 files changed, 22 insertions, 1 deletions

diff --git a/build-initramfs.sh b/build-initramfs.sh
index dcf52636..2b31f55b 100755
--- a/build-initramfs.sh
+++ b/build-initramfs.sh
@@ -34,6 +34,14 @@ use_systemd_in_initramfs='no'
 declare -rg _repo_dir="${_root_dir}/systemd-init"
 declare -rg _dracut_dir="${_root_dir}/dracut"
 
+# Autodetect the kmod version present on the system to decide which dracut version to get
+#  * v47 requires kmod >= 23 (Available in Ubuntu 18.04)
+#  * v46 works with kmod == 20 (CentOS 7.5 only provides kmod v20)
+declare -g _dracut_version="046"
+if [ "$(pkg-config --modversion libkmod)" -ge 23 ]; then
+	_dracut_version="047"
+fi
+
 declare -A core_repo=(
   [handler]="git"
      [path]="$_repo_dir"
@@ -44,7 +52,7 @@ declare -A core_repo=(
 declare -A core_dracut=(
   [handler]="http"
      [path]="$_dracut_dir"
-      [url]="https://www.kernel.org/pub/linux/utils/boot/dracut/dracut-047.tar.gz"
+      [url]="https://www.kernel.org/pub/linux/utils/boot/dracut/dracut-${_dracut_version}.tar.gz"
 )
 
 declare -A module_dnbd3=(
@@ -90,6 +98,19 @@ declare -A override
 bootstrap() {
 	for module in "${!core_@}" "${!module_@}"; do
 		declare -n _ref="$module"
+		if [ "$?" -ne 0 ]; then
+			echo "Only bash >= 4.3 supports namerefs." \
+				"You are running ${BASH_VERSION}." \
+				"Falling back to using evil eval..."
+			eval 'declare -A _ref=(' \
+				'[handler]=${'$module'[handler]}' \
+				   '[path]=${'$module'[path]}' \
+				    '[url]=${'$module'[url]}' \
+				 '[branch]=${'$module'[branch]}' \
+				 '[commit]=${'$module'[commit]}' \
+				')'
+			# phew that was ugly....
+		fi
 		if [ -n "$(ls -A "${_ref[path]}" 2> /dev/null)" ]; then
 			echo "'${_ref[path]}' not empty, skipping..."
 			continue