templates: mount devtmpfs in ubuntu containers

templates/lxc-ubuntu-cloud.in

@@ -95,6 +95,10 @@ EOF
 proc            proc         proc    nodev,noexec,nosuid 0 0
 sysfs           sys          sysfs defaults  0 0
 EOF
+    if grep devtmpfs /proc/filesystems > /dev/null 2>&1; then
+cat <<EOF >> $path/fstab
+devtmpfs        dev          devtmpfs defaults 0 0
+EOF
 
     # rmdir /dev/shm for containers that have /run/shm
     # I'm afraid of doing rm -rf $rootfs/dev/shm, in case it did

templates/lxc-ubuntu.in

@@ -353,6 +353,10 @@ EOF
 proc            proc         proc    nodev,noexec,nosuid 0 0
 sysfs           sys          sysfs defaults  0 0
 EOF
+    if grep devtmpfs /proc/filesystems > /dev/null 2>&1; then
+cat <<EOF >> $path/fstab
+devtmpfs        dev          devtmpfs defaults 0 0
+EOF
 
     if [ $? -ne 0 ]; then
         echo "Failed to add configuration"