Allow installing tempest only with keystone

Modify the lib/tempest to not fail
 if no nova or glance available.

* This allows performance test of keystone and neutron with
  tempest (or tempest stress runner) without having system
  noise from another components.
* Depending on not required components for tempest is bad practice,
  tempest service decorators expected to allow tempest,
  to run in more minimal system out-of-the-box.

Change-Id: Ifc40b1eb5c4b79d96a5fae919b88afecca642ca0

lib/tempest

@@ -110,6 +110,7 @@ function configure_tempest {
     # ... Also ensure we only take active images, so we don't get snapshots in process
     declare -a images
 
+    if is_service_enabled glance; then
         while read -r IMAGE_NAME IMAGE_UUID; do
             if [ "$IMAGE_NAME" = "$DEFAULT_IMAGE_NAME" ]; then
                 image_uuid="$IMAGE_UUID"
@@ -138,6 +139,7 @@ function configure_tempest {
                 fi
                 ;;
         esac
+    fi
 
     # Create tempest.conf from tempest.conf.sample
     # copy every time, because the image UUIDS are going to change
@@ -161,6 +163,7 @@ function configure_tempest {
     ALT_TENANT_NAME=${ALT_TENANT_NAME:-alt_demo}
     ADMIN_TENANT_ID=$(openstack project list | awk "/ admin / { print \$2 }")
 
+    if is_service_enabled nova; then
         # If the ``DEFAULT_INSTANCE_TYPE`` not declared, use the new behavior
         # Tempest creates instane types for himself
         if  [[ -z "$DEFAULT_INSTANCE_TYPE" ]]; then
@@ -219,6 +222,7 @@ function configure_tempest {
                 fi
             done
         fi
+    fi
 
     if [ "$Q_USE_NAMESPACE" != "False" ]; then
         tenant_networks_reachable=false
@@ -460,6 +464,7 @@ function init_tempest {
     local kernel="$image_dir/${base_image_name}-vmlinuz"
     local ramdisk="$image_dir/${base_image_name}-initrd"
     local disk_image="$image_dir/${base_image_name}-blank.img"
+    if is_service_enabled nova; then
         # if the cirros uec downloaded and the system is uec capable
         if [ -f "$kernel" -a -f "$ramdisk" -a -f "$disk_image" -a  "$VIRT_DRIVER" != "openvz" \
             -a \( "$LIBVIRT_TYPE" != "lxc" -o "$VIRT_DRIVER" != "libvirt" \) ]; then
@@ -475,6 +480,7 @@ function init_tempest {
         else
             echo "Boto materials are not prepared"
         fi
+    fi
 }
 
 # Restore xtrace