xend: Add interface name definition support for xend-relocation-address

Add a new feature for xend-relocation-address option to support
definition by interface name which can be useful for people having
e.g. a cluster environment with multiple network interfaces on all of
the machines with only one reserved to be registered to a private
cluster network. This way they won't need to specify the relocation
address manually on all the machines but just simple providing the
interface name to get the IP address from would do the job (all the
machines have to have this interface named the same to make it
working, of course).

Technically it reads the interface name and gets its IP address using
ioctl call of SIOCGIFADDR and if the interface doesn't have the
address, i.e. if non-existing interface or hostname was provided the
original ifname is returned to preserve the old behaviour.

Signed-off-by: Michal Novotny <minovotn@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/tools/examples/xend-config.sxp b/tools/examples/xend-config.sxp
index 6c056d4e05..7ab7eb8f38 100644
--- a/tools/examples/xend-config.sxp
+++ b/tools/examples/xend-config.sxp
@@ -110,6 +110,8 @@
 # Address xend should listen on for relocation-socket connections, if
 # xend-relocation-server is set.
 # Meaning and default as for xend-address above.
+# Also, interface name is allowed (e.g. eth0) there to get the
+# relocation address to be bound on.
 #(xend-relocation-address '')
 
 # The hosts allowed to talk to the relocation port.  If this is empty (the