initoverlayfs-install: generic improvements

- split extract_initrd_into_initoverlayfs() - add exec_cmd() to validate commands - remove unneeded |--* in case statement - use less verbose removing the requirement set -ex - replace initoverlayfs_conf with constant - remove unused no_kern - fix some shellcheck warnings Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
containers · Oct 30, 2023 · e5d9a4c · e5d9a4c
1 parent 7e7f855
commit e5d9a4c
Showing 1 changed file with 103 additions and 52 deletions.
diff --git a/bin/initoverlayfs-install b/bin/initoverlayfs-install
@@ -1,58 +1,114 @@
 #!/bin/bash
 
-set -ex
+# Constants with default value
+DECOMPRESSOR="lz4cat"
+DECOMPRESSOR_DRACUT="--lz4"
 
-extract_initrd_into_initoverlayfs() {
- DIR_TO_DUMP_INITRAMFS="/var/tmp/initoverlayfs"
- mkdir -p "$DIR_TO_DUMP_INITRAMFS"
-
- file_type=$(file /boot/initramfs-$kver.img)
- decompressor="lz4cat"
- decompressor_dracut="--lz4"
- if [[ "$file_type" == *"ASCII cpio archive (SVR4 with no CRC)"* ]]; then
- decompressor_dracut=""
- decompressor="zcat"
- elif [[ "$file_type" == *"regular file, no read permission"* ]] || \
-  [[ "$file_type" == *"gzip"* ]]; then
- decompressor_dracut=""
- decompressor="zcat"
- fi
-
- if command -v mkfs.erofs; then
- fstype="erofs"
- cd "$DIR_TO_DUMP_INITRAMFS"
- /usr/lib/dracut/skipcpio /boot/initramfs-$kver.img | $decompressor | cpio -ivd
- cd -
- rm -f /boot/initoverlayfs-$kver.img
- mkfs.erofs /boot/initoverlayfs-$kver.img "$DIR_TO_DUMP_INITRAMFS"
- else
- echo "Please install mkfs.erofs"
- exit 0
-
- fstype="ext4"
- dd if=/dev/zero of=/boot/initoverlayfs-$kver.img bs=64M count=1
- dev=$(losetup -fP --show /boot/initoverlayfs-$kver.img)
- mkfs.$fstype $dev
- mount $dev "$DIR_TO_DUMP_INITRAMFS"
- cd "$DIR_TO_DUMP_INITRAMFS"
- /usr/lib/dracut/skipcpio /boot/initramfs-$kver.img | zstd -d --stdout | cpio -ivd
- sync
- cd -
- while ! umount "$DIR_TO_DUMP_INITRAMFS"; do
+INITOVERLAYFS_CONF="/etc/initoverlayfs.conf"
+INITRAMFS_DUMP_DIR="/var/tmp/initoverlayfs"
+
+SUPPORTED_FILESYSTEM=("erofs" "ext4")
+SKIPCPIO_BIN="/usr/lib/dracut/skipcpio"
+
+exec_cmd() {
+  local cmd="$1"
+ eval "$cmd"
+ local exit_code="$?"
+
+ if [ "$exit_code" -ne 0 ]; then
+  echo "Error: Command failed with exit code $exit_code"
+  exit "$exit_code"
+  fi
+}
+
+exec_erofs() {
+ pushd "${INITRAMFS_DUMP_DIR}" || exit
+  exec_cmd "${SKIPCPIO_BIN} /boot/initramfs-${kver}.img | ${DECOMPRESSOR} | cpio -ivd"
+ popd || exit
+ exec_cmd "rm -f /boot/initoverlayfs-${kver}.img"
+ exec_cmd "mkfs.erofs /boot/initoverlayfs-${kver}.img ${INITRAMFS_DUMP_DIR}"
+}
+
+exec_ext4() {
+ exec_cmd "dd if=/dev/zero of=/boot/initoverlayfs-${kver}.img bs=64M count=1"
+ dev=$(losetup -fP --show /boot/initoverlayfs-"${kver}".img)
+ exec_cmd "mkfs.ext4 ${dev}"
+ exec_cmd "mount ${dev} ${INITRAMFS_DUMP_DIR}"
+
+ pushd "${INITRAMFS_DUMP_DIR}" || exit
+  "${SKIPCPIO_BIN}" /boot/initramfs-"${kver}".img | zstd -d --stdout | cpio -ivd
+  exec_cmd "sync"
+ popd || exit
+
+ while ! umount "$INITRAMFS_DUMP_DIR"; do
  sleep 1
  done
 
- losetup -d $dev
- fi
+ exec_cmd "losetup -d ${dev}"
+}
+
+detect_initramfs() {
+ if [ ! -d "${INITRAMFS_DUMP_DIR}" ]; then
+ mkdir -p "${INITRAMFS_DUMP_DIR}"
+ fi
+
+ echo "Extracting initrd into initoverlayfs..."
+
+ file_type=$(file /boot/initramfs-"${kver}".img)
+ case "${file_type}" in
+ *"ASCII cpio archive (SVR4 with no CRC)"*)
+ DECOMPRESSOR_DRACUT=""
+ DECOMPRESSOR="zcat"
+ ;;
+ *"regular file, no read permission"*|"gzip"*)
+ DECOMPRESSOR_DRACUT=""
+ DECOMPRESSOR="zcat"
+ ;;
+ esac
+
+ # Set delimiter for splitting the string
+ IFS=":"
+ read -r file_path file_desc <<< "${file_type}"
+ echo " - File path: ${file_path}"
+ echo " - File Description: ${file_desc}"
+ echo " - Decompressor: ${DECOMPRESSOR}"
+ echo " - Decompressor Dracut: ${DECOMPRESSOR_DRACUT}"
 }
 
+extract_initrd_into_initoverlayfs() {
+ if command -v mkfs.erofs; then
+ fstype="erofs"
+ elif command -v mkfs.ext4; then
+ fstype="ext4"
+ else
+ fstype="unsupported"
+ fi
+
+ case "${fstype}" in
+ *ext4*)
+ exec_ext4
+ ;;
+ *erofs*)
+ exec_erofs
+ ;;
+ *)
+ echo -e "The detected filesytem: is ${fstype}." \
+ "Unfortunately it's not supported at moment."
+ echo -e "Supported filesystems: ${SUPPORTED_FILESYSTEM[*]}"
+ exit 1
+ ;;
+ esac
+}
+
+# main()
+
 while [[ $# -gt 0 ]]; do
  case $1 in
  --kver)
  kver="$2"
  shift 2
  ;;
- -*|--*)
+ -*)
  echo "Unknown option $1"
  exit 1
  ;;
@@ -66,22 +122,17 @@ if [ -z "$kver" ]; then
  kver="$(uname -r)"
 fi
 
-initoverlayfs_conf="/etc/initoverlayfs.conf"
-if ! [ -e "$initoverlayfs_conf" ]; then
- boot_partition=$(cat /etc/fstab | grep "/boot.*ext4" | awk '{print $1}')
- echo -e "bootfs $boot_partition\nbootfstype ext4\ninitoverlayfs_builder dracut -H -f -v -M --reproducible -o \"initoverlayfs\"\ninitrd_builder dracut -H -f -v -M --reproducible -m \"kernel-modules udev-rules initoverlayfs\" -o \"bash systemd systemd-initrd i18n kernel-modules-extra rootfs-block dracut-systemd usrmount base fs-lib microcode_ctl-fw_dir_override shutdown nss-softokn\"\nudev_trigger udevadm trigger --type=devices --action=add --subsystem-match=module --subsystem-match=block --subsystem-match=virtio --subsystem-match=pci --subsystem-match=nvme\n" > $initoverlayfs_conf
-fi
-
-no_kern=""
-if ! compgen -G /boot/vmlinu* > /dev/null; then
- no_kern="--no-kernel"
+if ! [ -e "$INITOVERLAYFS_CONF" ]; then
+ boot_partition=$(< /etc/fstab grep "/boot.*ext4" | awk '{print $1}')
+ echo -e "bootfs $boot_partition\nbootfstype ext4\ninitoverlayfs_builder dracut -H -f -v -M --reproducible -o \"initoverlayfs\"\ninitrd_builder dracut -H -f -v -M --reproducible -m \"kernel-modules udev-rules initoverlayfs\" -o \"bash systemd systemd-initrd i18n kernel-modules-extra rootfs-block dracut-systemd usrmount base fs-lib microcode_ctl-fw_dir_override shutdown nss-softokn\"\nudev_trigger udevadm trigger --type=devices --action=add --subsystem-match=module --subsystem-match=block --subsystem-match=virtio --subsystem-match=pci --subsystem-match=nvme\n" > $INITOVERLAYFS_CONF
 fi
 
-initoverlayfs_builder=$(sed -ne "s/^initoverlayfs_builder\s//pg" "$initoverlayfs_conf")
+initoverlayfs_builder=$(sed -ne "s/^initoverlayfs_builder\s//pg" "$INITOVERLAYFS_CONF")
 /bin/bash -c "$initoverlayfs_builder"
 
+detect_initramfs
 extract_initrd_into_initoverlayfs
 
-initrd_builder=$(sed -ne "s/^initrd_builder\s//pg" "$initoverlayfs_conf")
+initrd_builder=$(sed -ne "s/^initrd_builder\s//pg" "$INITOVERLAYFS_CONF")
 /bin/bash -c "$initrd_builder"