Ensure tempest writes a full manifest

The tempest element uses pip install after generating the manifest,
meaning that it installs software not listed in its manifest.

Fix it so that it writes the manifest after the last of these
installs.

Change-Id: I456d650c0bcba448cb18efad95e7daeccd5d9e0b

elements/tempest/install.d/51-tempest

@@ -1,19 +1,38 @@
 #!/usr/bin/env bash
 
-set -ex
+set -eux
+set -o pipefail
 
 install-packages augeas-tools
 
 os-svc-install $TEMPEST_EXTRA_INSTALL_OPTS -i "$TEMPEST_VENV_DIR" -u tempest -r /opt/stack/tempest
 
+set +u
 source $TEMPEST_VENV_DIR/bin/activate
+set -u
+
 cd /opt/stack/tempest
 # bug #1293812 : Avoid easy_install triggering on pbr.
 pip install -U 'pbr>=0.5.21,<1.0'
 
 pip install -r test-requirements.txt
+
+# Fix for creating and using a pip manifest correctly
+name=$(basename $TEMPEST_VENV_DIR)
+svc_manifest=$(get-pip-manifest $name)
+if [ -n "$svc_manifest" ]; then
+    use-pip-manifest $svc_manifest
+else
+    write-pip-manifest $name
+fi
+
 testr init
 
+# Deactivate the virtualenv after use
+set +u
+deactivate
+set -u
+
 # soft link testr into PATH so we can use it directly in run-tempest
 ln -sf $TEMPEST_VENV_DIR/bin/testr /usr/local/bin/testr