openvswitch and openvswitch-datapath element

Split out the openvswitch installation from the neutron element.

Don't install openvswitch dkms modules in kernel >= 3.12
Openvswitch GRE and VXLAN capabilities are now included in
vanilla kernels (GRE tunneling support in 3.11 and VXLAN in
3.12) so there is no need to install the dkms packages to activate
them. When installing the datapath package, dkms will fail at
compile time with an unsupported kernel version message.

Change-Id: Id456cfb1a0634f43617c23ac82fc4445a58ddb2c
Partial-bug: #1316985

elements/openvswitch-datapath/README.md

@@ -0,0 +1,4 @@
+Install openvswitch datapath from packages.
+
+Note: For kernels >= 3.12 there is no need to install
+the dkms datapath to get GRE and VXLAN support.

elements/openvswitch-datapath/element-deps

@@ -0,0 +1,2 @@
+openvswitch
+select-boot-kernel-initrd

elements/openvswitch-datapath/install.d/75-openvswitch-datapath

@@ -0,0 +1,13 @@
+#!/bin/bash
+set -eux
+
+RET=$(select-boot-kernel-initrd)
+KERNEL_VERSION=`echo ${RET%:*} | sed 's/vmlinuz-//g' | cut -f-2 -d'.'`
+maj=$(printf "%02d" ${KERNEL_VERSION%.*})
+min=$(printf "%02d" ${KERNEL_VERSION#*.})
+
+# Open vSwitch GRE tunneling included in kernel 3.11 and
+# VXLAN tunneling in kernel 3.12
+if [[ $((10#$maj$min)) -lt 312 ]]; then
+    install-packages openvswitch-datapath-dkms
+fi

elements/openvswitch/README.md

@@ -0,0 +1,5 @@
+Install openvswitch from packages.
+
+Enables the openvswitch service for systemd systems and
+and adds an upstart script service to override the default
+sysv one on systems with upstart.

elements/openvswitch/element-deps

@@ -0,0 +1 @@
+os-svc-install

elements/openvswitch/install.d/74-openvswitch

@@ -0,0 +1,24 @@
+#!/bin/bash
+set -eux
+
+install-packages openvswitch-switch
+
+if [ "$DIB_INIT_SYSTEM" == "systemd" ] ; then
+    os-svc-enable -n openvswitch-switch
+fi
+
+if [ "$DIB_INIT_SYSTEM" == "upstart" ] ; then
+    echo "start on starting cloud-init-nonet" >> /etc/init/openvswitch-switch.override
+    if [ ! -f /etc/init/openvswitch-switch.conf ] ; then
+        cat << 'EOF' > /etc/init/openvswitch-switch.conf
+# openvswitch-switch
+# the purpose of this job is
+#  * start openvwitch-switch in upstart rather than SysV startup
+pre-start script
+      export RUNLEVEL=2
+      /etc/init.d/openvswitch-switch start
+end script
+post-stop exec /etc/init.d/openvswitch-switch stop
+EOF
+    fi
+fi