[Ovirt-devel] [PATCH node-image] clean up quoting, cleanup-on-exception, use mktemp-not-/tmp, etc.

[Jim Meyering]

---
 ovirt-flash-static |   77 ++++++++++++++++++++++++++++++++++++---------------
 1 files changed, 54 insertions(+), 23 deletions(-)

diff --git a/ovirt-flash-static b/ovirt-flash-static
index 4c2bb22..00b26de 100755
--- a/ovirt-flash-static
+++ b/ovirt-flash-static
@@ -26,39 +26,70 @@ test $# != 2 && die "Usage: $ME <usbdevice> <iso-image>"
 USBDEVICE=$1
 ISO=$2

-test ! -r $ISO && die "$ISO is not a readable file"
-test ! -b $USBDEVICE && die "$USBDEVICE is not a valid block device"
+test ! -r "$ISO" && die "$ISO is not a readable file"
+test ! -b "$USBDEVICE" && die "$USBDEVICE is not a valid block device"
 test $( id -u ) -ne 0 && die "$ME must run as root"

-IMGTMP=/var/tmp/ovirt-$$
-SQUASHTMP=/var/tmp/ovirt-squash-$$
-USBTMP=/var/tmp/ovirt-usb-$$
+case $ISO in
+    *.iso) ;;
+    *) die "ME: ISO file name, '$ISO' lacks .iso suffix"
+esac
+
+tmpdir=$(mktemp -d) || exit 1
+
+IMGTMP="$tmpdir/ovirt"
+SQUASHTMP="$tmpdir/ovirt-squash"
+USBTMP="$tmpdir/ovirt-usb"
+
+cleanup()
+{
+  { umount "$USBTMP"
+    umount "$SQUASHTMP"
+    umount "$IMGTMP"
+  } 2> /dev/null || :
+  rm -rf "$tmpdir"
+}
+trap cleanup 0
+trap 'Exit $?' 1 2 13 15
+
+# From here on, any failure makes the script fail.
+set -e

 # do setup
-mkdir -p $IMGTMP $SQUASHTMP $USBTMP
-mount -o loop $ISO $IMGTMP
-mount -o loop $IMGTMP/LiveOS/squashfs.img $SQUASHTMP
+mkdir -p "$IMGTMP" "$SQUASHTMP" "$USBTMP"
+mount -o loop "$ISO" "$IMGTMP"
+
+squashfs_img="$IMGTMP/LiveOS/squashfs.img"
+find "$IMGTMP" # FIXME
+test -f "$squashfs_img" \
+  || die "not a LiveCD image: $ISO"
+
+mount -o loop "$squashfs_img" "$SQUASHTMP"

 # clear out the old partition table
-dd if=/dev/zero of=$USBDEVICE bs=4096 count=1
-printf 'n\np\n1\n\n\nt\n83\na\n1\nw\n' | fdisk $USBDEVICE
+dd if=/dev/zero of="$USBDEVICE" bs=4096 count=1
+printf 'n\np\n1\n\n\nt\n83\na\n1\nw\n' | fdisk "$USBDEVICE"

-cat /usr/lib/syslinux/mbr.bin > $USBDEVICE
-dd if=$SQUASHTMP/LiveOS/ext3fs.img of=${USBDEVICE}1
+cat /usr/lib/syslinux/mbr.bin > "$USBDEVICE"
+dd if="$SQUASHTMP/LiveOS/ext3fs.img" of="${USBDEVICE}1"

-mount ${USBDEVICE}1 $USBTMP
+mount "${USBDEVICE}1" "$USBTMP"

-cp $IMGTMP/isolinux/* $USBTMP
+cp "$IMGTMP"/isolinux/* "$USBTMP"

-rm -f $USBTMP/isolinux.bin
-mv $USBTMP/isolinux.cfg $USBTMP/extlinux.conf
+rm -f "$USBTMP/isolinux.bin"
+mv "$USBTMP/isolinux.cfg" "$USBTMP/extlinux.conf"

-LABEL=`echo $ISO | cut -d'.' -f1 | cut -c-16`
-sed -i -e "s/ *append.*/  append initrd=initrd.img root=LABEL=$LABEL ro/" $USBTMP/extlinux.conf
+iso_base=$(basename "$ISO" .iso)
+# sanitize for sed and the label name and limit to 16 bytes
+LABEL=$(echo "$iso_base" | cut -b-16 | tr -c '[[:alnum:]_.-]' _)
+sed -i -e "s/ *append.*/  append initrd=initrd.img root=LABEL=$LABEL ro/" \
+    "$USBTMP/extlinux.conf"

-extlinux -i $USBTMP
+extlinux -i "$USBTMP"

-umount $USBTMP
-umount $SQUASHTMP
-umount $IMGTMP
-rm -rf $SQUASHTMP $IMGTMP $USBTMP
+# To test:
+cat <<\EOF > /dev/null
+mkdir -p t/LiveOS && (cd t/LiveOS && touch ext3fs.img squashfs.img)
+genisoimage -U -o k2.iso t
+EOF
--
1.6.1.rc1.279.g45d11