New option DISK_FOLLOW_SYMLINKS

If DISK_FOLLOW_SYMLINKS=yes then for any disk image paths that are a
symlink, follow the symlink when creating the image.

This allows disk images to be reorganised, perhaps across several
disks, and replaced with symlinks.  On the next cluster creation the
symlinks will be respected and the layout of disk images will be
maintained.

Signed-off-by: Martin Schwenke <martin@meltin.net>

4 files changed, 27 insertions, 7 deletions

diff --git a/autocluster b/autocluster
index f5fae9f..cec09e4 100755
--- a/autocluster
+++ b/autocluster
@@ -197,28 +197,32 @@ create_node_COMMON ()
 
     mkdir -p $VIRTBASE/$CLUSTER tmp
 
-    rm -f "$DISK"
+    local di="$DISK"
+    if [ "$DISK_FOLLOW_SYMLINKS" = "yes" -a -L "$DISK" ] ; then
+	di=$(readlink "$DISK")
+    fi
+    rm -f "$di"
     case "$SYSTEM_DISK_FORMAT" in
 	qcow2)
 	    echo "Creating the disk..."
-	    qemu-img create -b "$base_disk" -f qcow2 "$DISK"
+	    qemu-img create -b "$base_disk" -f qcow2 "$di"
 	    create_node_configure_image "$DISK" "$type"
 	    ;;
 	raw)
 	    echo "Creating the disk..."
-	    cp -v --sparse=always "$base_disk" "$DISK"
+	    cp -v --sparse=always "$base_disk" "$di"
 	    create_node_configure_image "$DISK" "$type"
 	    ;;
 	reflink)
 	    echo "Creating the disk..."
-	    cp -v --reflink=always "$base_disk" "$DISK"
+	    cp -v --reflink=always "$base_disk" "$di"
 	    create_node_configure_image "$DISK" "$type"
 	    ;;
 	mmclone)
 	    echo "Creating the disk (using mmclone)..."
 	    local base_snap="${base_disk}.snap"
 	    [ -f "$base_snap" ] || mmclone snap "$base_disk" "$base_snap"
-	    mmclone copy "$base_snap" "$DISK"
+	    mmclone copy "$base_snap" "$di"
 	    create_node_configure_image "$DISK" "$type"
 	    ;;
 	none)
@@ -488,8 +492,13 @@ create_base() {
     echo "Testing WEBPROXY $WEBPROXY"
     test_proxy
 
+    local di="$DISK"
+    if [ "$DISK_FOLLOW_SYMLINKS" = "yes" -a -L "$DISK" ] ; then
+	di=$(readlink "$DISK")
+    fi
+
     echo "Creating the disk"
-    qemu-img create -f $BASE_FORMAT "$DISK" $DISKSIZE
+    qemu-img create -f $BASE_FORMAT "$di" $DISKSIZE
 
     rm -rf tmp
     mkdir -p mnt tmp tmp/ISO
diff --git a/config.d/00base.defconf b/config.d/00base.defconf
index 5cb7d1c..ba39c06 100644
--- a/config.d/00base.defconf
+++ b/config.d/00base.defconf
@@ -40,6 +40,9 @@ defconf BASENAME "ac-base" \
 defconf BASE_PER_NODE_TYPE "no" \
 	"<yes|no>" "Use per-node-type base images"
 
+defconf DISK_FOLLOW_SYMLINKS "no" \
+	"<yes|no>" "If disk images use symlinks then follow them to overwrite"
+
 ######################################################################
 
 # Virtualisation
diff --git a/config.d/10shareddisk.defconf b/config.d/10shareddisk.defconf
index 903727c..d53765d 100644
--- a/config.d/10shareddisk.defconf
+++ b/config.d/10shareddisk.defconf
@@ -128,6 +128,9 @@ EOF
 	local i
 	for i in $(seq 1 $SHAREDDISK_COUNT); do
 	    local f="$VIRTBASE/$CLUSTER/shared$i"
+	    if [ "$DISK_FOLLOW_SYMLINKS" = "yes" -a -L "$f" ] ; then
+		f=$(readlink "$f")
+	    fi
 	    rm -f "$f"
 	    if [ "$SHARED_DISK_TYPE" = "iscsi" ] ; then
 		dd if=/dev/zero seek=$SHAREDDISKSIZE bs=1 count=1 of="$f"
diff --git a/config.d/60tsm.defconf b/config.d/60tsm.defconf
index 8e2aacd..1e22f1d 100644
--- a/config.d/60tsm.defconf
+++ b/config.d/60tsm.defconf
@@ -84,8 +84,13 @@ create_node_tsm_server ()
     echo "Creating TSM server node $name"
     create_node_COMMON "$name" "$ip_offset" "$type" "$TSM_TEMPLATE"
 
+    local di="$TSMDISK"
+    if [ "$DISK_FOLLOW_SYMLINKS" = "yes" -a -L "$TSMDISK" ] ; then
+	di=$(readlink "$TSMDISK")
+    fi
+
     echo "Creating tsm disk"
-    qemu-img create -f qcow2 "$TSMDISK" $TSMDISKSIZE
+    qemu-img create -f qcow2 "$di" $TSMDISKSIZE
 
     echo
 }