Add reusing Tempest stestr timing data

This patch aims to help jobs save time when executing Tempest
tests. This is done by reusing stestr timing data that are saved
during the run.

Author: kstrenkova

container-images/tcib/base/os/tempest/run_tempest.sh

@@ -349,6 +349,10 @@ function run_tempest {
 
     upload_extra_images
 
+    if [[ -n "${TEMPEST_TIMING_DATA_URL:-}" ]]; then
+        curl -L "${TEMPEST_TIMING_DATA_URL}" | tar -xz --strip-components=1 -C "${TEMPEST_DIR}/.stestr"
+    fi
+
     mkdir -p "${TEMPEST_LOGS_DIR}"
 
     discover_tempest_config ${TEMPESTCONF_ARGS} ${TEMPESTCONF_OVERRIDES} \
@@ -444,7 +448,7 @@ function save_config_files {
     cp -f "${TEMPEST_DIR}/etc/"*.{conf,ini,txt,yaml} "${TEMPEST_LOGS_DIR}/etc"
 
     cp -f "${TEMPEST_DIR}/.stestr.conf" "${TEMPEST_LOGS_DIR}/stestr.conf"
-    cp -rf "${TEMPEST_DIR}/.stestr" "${TEMPEST_LOGS_DIR}/stestr"
+    tar -czf "${TEMPEST_LOGS_DIR}/stestr.tar.gz" -C "${TEMPEST_DIR}" .stestr
 }