Allow use of /etc/os-release file

The top-level Makefile in VPP already uses the file /etc/os-release to
recognize which OS the build is being performed on.
The scripts for vagrant images instead were still using different files
for different distros and adding a new distro to be supported causes
issues with the extra-logic to deal with it.
This patch aligns the vagrant scripts to use the same approach followed
by the top-level Makefile and simplifies the steps to identify / update
the OS and build / run VPP.

Change-Id: I539f4a7c27b3fef70ed1c12b0276049bc47dc289
Signed-off-by: Marco Varlese <marco.varlese@suse.com>
diff --git a/extras/vagrant/run.sh b/extras/vagrant/run.sh
index 1cd3382..3c779fa 100755
--- a/extras/vagrant/run.sh
+++ b/extras/vagrant/run.sh
@@ -1,22 +1,21 @@
 #!/bin/bash
 
 # Figure out what system we are running on
-if [ -f /etc/lsb-release ];then
-    . /etc/lsb-release
-elif [ -f /etc/redhat-release ];then
-    yum install -y redhat-lsb
-    DISTRIB_ID=`lsb_release -si`
-    DISTRIB_RELEASE=`lsb_release -sr`
-    DISTRIB_CODENAME=`lsb_release -sc`
-    DISTRIB_DESCRIPTION=`lsb_release -sd`
+if [ "$(uname)" <> "Darwin" ]; then
+    OS_ID=$(grep '^ID=' /etc/os-release | cut -f2- -d= | sed -e 's/\"//g')
+    OS_VERSION_ID=$(grep '^VERSION_ID=' /etc/os-release | cut -f2- -d= | sed -e 's/\"//g')
 fi
 
-if [ $DISTRIB_ID == "CentOS" ]; then
+if [ "$OS_ID" == "ubuntu" ]; then
+    $OS_CODENAME=$UBUNTU_CODENAME
+fi
+
+if [ "$OS_ID" == "centos" ] || [ "$OS_ID" == "opensuse" ]; then
     # Install uio-pci-generic
     modprobe uio_pci_generic
 fi
 echo "Starting VPP..."
-if [ $DISTRIB_ID == "Ubuntu" ] && [ $DISTRIB_CODENAME = "trusty" ] ; then
+if [ "$OS_ID" == "ubuntu" ] && [ $OS_CODENAME = "trusty" ] ; then
     start vpp
 else
     service vpp start