diff --git a/lib/tempest b/lib/tempest
index f75d755..caf8f11 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -176,17 +176,18 @@
     sudo install -d -o $STACK_USER $TEMPEST_CONFIG_DIR
     rm -f $TEMPEST_CONFIG
 
-    password=${ADMIN_PASSWORD:-secrete}
+    local password=${ADMIN_PASSWORD:-secrete}
 
     # See ``lib/keystone`` where these users and tenants are set up
-    ADMIN_USERNAME=${ADMIN_USERNAME:-admin}
-    ADMIN_TENANT_NAME=${ADMIN_TENANT_NAME:-admin}
-    ADMIN_DOMAIN_NAME=${ADMIN_DOMAIN_NAME:-Default}
-    TEMPEST_USERNAME=${TEMPEST_USERNAME:-demo}
-    TEMPEST_TENANT_NAME=${TEMPEST_TENANT_NAME:-demo}
-    ALT_USERNAME=${ALT_USERNAME:-alt_demo}
-    ALT_TENANT_NAME=${ALT_TENANT_NAME:-alt_demo}
-    ADMIN_TENANT_ID=$(openstack project list | awk "/ admin / { print \$2 }")
+    local admin_username=${ADMIN_USERNAME:-admin}
+    local admin_tenant_name=${ADMIN_TENANT_NAME:-admin}
+    local admin_domain_name=${ADMIN_DOMAIN_NAME:-Default}
+    local tempest_username=${TEMPEST_USERNAME:-demo}
+    local tempest_tenant_name=${TEMPEST_TENANT_NAME:-demo}
+    local alt_username=${ALT_USERNAME:-alt_demo}
+    local alt_tenant_name=${ALT_TENANT_NAME:-alt_demo}
+    local admin_tenant_id
+    admin_tenant_id=$(openstack project list | awk "/ admin / { print \$2 }")
 
     if is_service_enabled nova; then
         # If ``DEFAULT_INSTANCE_TYPE`` is not declared, use the new behavior
@@ -260,11 +261,11 @@
     iniset $TEMPEST_CONFIG identity uri "$KEYSTONE_SERVICE_PROTOCOL://$KEYSTONE_SERVICE_HOST:5000/v2.0/"
     iniset $TEMPEST_CONFIG identity uri_v3 "$KEYSTONE_SERVICE_URI_V3"
     if [[ "$TEMPEST_HAS_ADMIN" == "True" ]]; then
-        iniset $TEMPEST_CONFIG auth admin_username $ADMIN_USERNAME
+        iniset $TEMPEST_CONFIG auth admin_username $admin_username
         iniset $TEMPEST_CONFIG auth admin_password "$password"
-        iniset $TEMPEST_CONFIG auth admin_tenant_name $ADMIN_TENANT_NAME
-        iniset $TEMPEST_CONFIG auth admin_tenant_id $ADMIN_TENANT_ID
-        iniset $TEMPEST_CONFIG auth admin_domain_name $ADMIN_DOMAIN_NAME
+        iniset $TEMPEST_CONFIG auth admin_tenant_name $admin_tenant_name
+        iniset $TEMPEST_CONFIG auth admin_tenant_id $admin_tenant_id
+        iniset $TEMPEST_CONFIG auth admin_domain_name $admin_domain_name
     fi
     if [ "$ENABLE_IDENTITY_V2" == "False" ]; then
         # Only Identity v3 is available; then skip Identity API v2 tests
@@ -531,8 +532,9 @@
     # this tempest service list needs to be all the services that
     # tempest supports, otherwise we can have an erroneous set of
     # defaults (something defaulting true in Tempest, but not listed here).
-    TEMPEST_SERVICES="key,glance,nova,neutron,cinder,swift,heat,ceilometer,horizon,sahara,ironic,trove"
-    for service in ${TEMPEST_SERVICES//,/ }; do
+    local service
+    local tempest_services="key,glance,nova,neutron,cinder,swift,heat,ceilometer,horizon,sahara,ironic,trove"
+    for service in ${tempest_services//,/ }; do
         if is_service_enabled $service ; then
             iniset $TEMPEST_CONFIG service_available $service "True"
         else
@@ -550,9 +552,9 @@
     iniset $TEMPEST_CONFIG auth tempest_roles "Member"
     if [[ $TEMPEST_USE_TEST_ACCOUNTS == "True" ]]; then
         if [[ $TEMPEST_HAS_ADMIN == "True" ]]; then
-            tempest-account-generator -c $TEMPEST_CONFIG --os-username $ADMIN_USERNAME --os-password $ADMIN_PASSWORD --os-tenant-name $ADMIN_TENANT_NAME -r $TEMPEST_CONCURRENCY --with-admin etc/accounts.yaml
+            tempest-account-generator -c $TEMPEST_CONFIG --os-username $admin_username --os-password $admin_password --os-tenant-name $admin_tenant_name -r $TEMPEST_CONCURRENCY --with-admin etc/accounts.yaml
         else
-            tempest-account-generator -c $TEMPEST_CONFIG --os-username $ADMIN_USERNAME --os-password $ADMIN_PASSWORD --os-tenant-name $ADMIN_TENANT_NAME -r $TEMPEST_CONCURRENCY etc/accounts.yaml
+            tempest-account-generator -c $TEMPEST_CONFIG --os-username $admin_username --os-password $admin_password --os-tenant-name $admin_tenant_name -r $TEMPEST_CONCURRENCY etc/accounts.yaml
         fi
         iniset $TEMPEST_CONFIG auth use_dynamic_credentials False
         iniset $TEMPEST_CONFIG auth test_accounts_file "etc/accounts.yaml"