Move neutron cache dir into a function

Taking the model of Nova, this patch aims to move the cache directory
management into a function with the goal to reuse it somewhere else like
Grenade.

Change-Id: I93df52f69ef339e6528b88d88d4ea70e0b725893
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
diff --git a/lib/neutron b/lib/neutron
index 70417be..8b0656b 100644
--- a/lib/neutron
+++ b/lib/neutron
@@ -17,6 +17,7 @@
 # - configure_neutron_third_party
 # - init_neutron_third_party
 # - start_neutron_third_party
+# - create_neutron_cache_dir
 # - create_nova_conf_neutron
 # - start_neutron_service_and_check
 # - create_neutron_initial_network
@@ -296,6 +297,14 @@
     fi
 }
 
+# create_neutron_cache_dir() - Part of the _neutron_setup_keystone() process
+function create_neutron_cache_dir() {
+    # Create cache dir
+    sudo mkdir -p $NEUTRON_AUTH_CACHE_DIR
+    sudo chown $STACK_USER $NEUTRON_AUTH_CACHE_DIR
+    rm -f $NEUTRON_AUTH_CACHE_DIR/*
+}
+
 # create_neutron_accounts() - Set up common required neutron accounts
 
 # Tenant               User       Roles
@@ -782,9 +791,7 @@
     if [[ -z $skip_auth_cache ]]; then
         iniset $conf_file $section signing_dir $NEUTRON_AUTH_CACHE_DIR
         # Create cache dir
-        sudo mkdir -p $NEUTRON_AUTH_CACHE_DIR
-        sudo chown $STACK_USER $NEUTRON_AUTH_CACHE_DIR
-        rm -f $NEUTRON_AUTH_CACHE_DIR/*
+        create_neutron_cache_dir
     fi
 }