Reinstate "autocluster create node" functionality.

This was removed several months ago when the node types were
generalised and it didn't seem to make sense at the time.

The new version takes an IP offset as its second argument and creates
the corresponding node.  It doesn't run the create cluster hooks,
since they may do cluster-wide things.

Note that creating a single node can result in an inconsistent
cluster.  For example, the when creating a node that is part of a CTDB
or GPFS cluster the behaviour is not well specified.  However, this
function may be very useful for (re)creating rhel_base and tsm_server
nodes.

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

1 files changed, 53 insertions, 15 deletions

diff --git a/autocluster b/autocluster
index 18599a4..73cb44b 100755
--- a/autocluster
+++ b/autocluster
@@ -271,21 +271,15 @@ register_create_cluster_hook ()
     create_cluster_hooks="${create_cluster_hooks}${create_cluster_hooks:+ }${hook}"
 }
 
-create_cluster() {
-    CLUSTER="$1"
-
-    [ -n "${CLUSTER//[A-Za-z0-9]}" ] && \
+sanity_check_cluster_name ()
+{
+    [ -z "${CLUSTER//[A-Za-z0-9]}" ] || \
 	die "Cluster names should be restricted to the characters A-Za-z0-9.  \
 Some cluster filesystems have problems with other characters."
+}
 
-    mkdir -p $VIRTBASE/$CLUSTER $KVMLOG tmp
-
-    # Run hooks before doing anything else.
-    local n
-    for n in $create_cluster_hooks ; do
-	$n
-    done
-
+common_nodelist_hacking ()
+{
     # Rework the NODES list
     expand_nodes
 
@@ -343,8 +337,24 @@ Some cluster filesystems have problems with other characters."
     local num_nodes=0
     hack_all_nodes_with ctdb_nodes_line >$nodes_file
     : "${NUMNODES:=${num_nodes}}"  # Set $NUMNODES if necessary
+}
+
+create_cluster ()
+{
+    CLUSTER="$1"
+
+    sanity_check_cluster_name
+
+    mkdir -p $VIRTBASE/$CLUSTER $KVMLOG tmp
+
+    # Run hooks before doing anything else.
+    local n
+    for n in $create_cluster_hooks ; do
+	$n
+    done
+
+    common_nodelist_hacking
 
-    # Create the actual nodes
     for_each_node call_func create_node
 
     echo "Cluster $CLUSTER created"
@@ -352,6 +362,30 @@ Some cluster filesystems have problems with other characters."
     cat $hosts_file
 }
 
+create_one_node ()
+{
+    CLUSTER="$1"
+    local single_node_ip_offset="$2"
+
+    sanity_check_cluster_name
+
+    mkdir -p $VIRTBASE/$CLUSTER $KVMLOG tmp
+
+    common_nodelist_hacking
+
+    for n in $NODES ; do
+	set -- $(IFS=: ; echo $n)
+	[ $single_node_ip_offset -eq $2 ] || continue
+	call_func create_node "$@"
+	
+	echo "Requested node created"
+	echo "You may want to update your /etc/hosts file:"
+	cat $hosts_file
+	
+	break
+    done
+}
+
 ###############################
 # test the proxy setup
 test_proxy() {
@@ -1083,11 +1117,15 @@ case $command in
 	case $type in
 	    base)
 		[ $# != 0 ] && usage
-		create_base;
+		create_base
 		;;
 	    cluster)
 		[ $# != 1 ] && usage
-		create_cluster "$1";
+		create_cluster "$1"
+		;;
+	    node)
+		[ $# != 2 ] && usage
+		create_one_node "$1" "$2"
 		;;
 	    *)
 		usage;