From e35b8ea2dcfc91760290dd6b80d0f337639cdd8c Mon Sep 17 00:00:00 2001
From: Slawek Kaplonski <skaplons@redhat.com>
Date: Thu, 1 Aug 2019 14:58:37 +0200
Subject: [PATCH] Add options to configure cache in nova

This patch adds new options:
* CACHE_BACKEND - with default "dogpile.cache.memcached"
* MEMCACHE_SERVERS - with default "localhost:1121"

to add possibility to configure various backends as cache in
Nova and Keystone.
It also adds options:
* KEYSTONE_ENABLE_CACHE - True by default
* NOVA_ENABLE_CACHE - True by default

To make possibility to enable and disable cache in those projects'
config files.

Default values configured there are the same as before were
hardcoded for Keystone config.

Nova has also enabled this cache by default.

Change-Id: I9082be077b59acd3a39910fa64e29147cb5c2dd7
Closes-Bug: #1836642
(cherry picked from commit d33cdd01f83b891b010e0fd238f1816910f3fd77)
---
 lib/keystone |  9 ++++++---
 lib/nova     | 12 ++++++++++--
 stackrc      |  4 ++++
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/lib/keystone b/lib/keystone
index 02e28222b7..3ea759abad 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -131,6 +131,9 @@ KEYSTONE_UNIQUE_LAST_PASSWORD_COUNT=${KEYSTONE_UNIQUE_LAST_PASSWORD_COUNT:-2}
 # however may not be suitable for real production.
 KEYSTONE_PASSWORD_HASH_ROUNDS=${KEYSTONE_PASSWORD_HASH_ROUNDS:-4}
 
+# Cache settings
+KEYSTONE_ENABLE_CACHE=${KEYSTONE_ENABLE_CACHE:-True}
+
 # Functions
 # ---------
 
@@ -213,9 +216,9 @@ function configure_keystone {
     iniset $KEYSTONE_CONF resource driver "$KEYSTONE_RESOURCE_BACKEND"
 
     # Enable caching
-    iniset $KEYSTONE_CONF cache enabled "True"
-    iniset $KEYSTONE_CONF cache backend "dogpile.cache.memcached"
-    iniset $KEYSTONE_CONF cache memcache_servers localhost:11211
+    iniset $KEYSTONE_CONF cache enabled $KEYSTONE_ENABLE_CACHE
+    iniset $KEYSTONE_CONF cache backend $CACHE_BACKEND
+    iniset $KEYSTONE_CONF cache memcache_servers $MEMCACHE_SERVERS
 
     iniset_rpc_backend keystone $KEYSTONE_CONF oslo_messaging_notifications
 
diff --git a/lib/nova b/lib/nova
index 4a3ae0e4d9..5ad756f0a4 100644
--- a/lib/nova
+++ b/lib/nova
@@ -94,6 +94,7 @@ NOVA_SERVICE_PROTOCOL=${NOVA_SERVICE_PROTOCOL:-$SERVICE_PROTOCOL}
 NOVA_SERVICE_LOCAL_HOST=${NOVA_SERVICE_LOCAL_HOST:-$SERVICE_LOCAL_HOST}
 NOVA_SERVICE_LISTEN_ADDRESS=${NOVA_SERVICE_LISTEN_ADDRESS:-$(ipv6_unquote $SERVICE_LISTEN_ADDRESS)}
 METADATA_SERVICE_PORT=${METADATA_SERVICE_PORT:-8775}
+NOVA_ENABLE_CACHE=${NOVA_ENABLE_CACHE:-True}
 
 # Option to enable/disable config drive
 # NOTE: Set ``FORCE_CONFIG_DRIVE="False"`` to turn OFF config drive
@@ -437,8 +438,8 @@ function create_nova_conf {
         iniset $NOVA_CONF DEFAULT bindir "/usr/bin"
     fi
 
-    # only setup database connections if there are services that
-    # require them running on the host. The ensures that n-cpu doesn't
+    # only setup database connections and cache backend if there are services
+    # that require them running on the host. The ensures that n-cpu doesn't
     # leak a need to use the db in a multinode scenario.
     if is_service_enabled n-api n-cond n-sched; then
         # If we're in multi-tier cells mode, we want our control services pointing
@@ -455,6 +456,13 @@ function create_nova_conf {
 
         iniset $NOVA_CONF database connection `database_connection_url $db`
         iniset $NOVA_CONF api_database connection `database_connection_url nova_api`
+
+        # Cache related settings
+        # Those settings aren't really needed in n-cpu thus it is configured
+        # only on nodes which runs controller services
+        iniset $NOVA_CONF cache enabled $NOVA_ENABLE_CACHE
+        iniset $NOVA_CONF cache backend $CACHE_BACKEND
+        iniset $NOVA_CONF cache memcache_servers $MEMCACHE_SERVERS
     fi
 
     if is_service_enabled n-api; then
diff --git a/stackrc b/stackrc
index 87eef1cde2..2bdbb41f9a 100644
--- a/stackrc
+++ b/stackrc
@@ -774,6 +774,10 @@ ETCD_DOWNLOAD_LOCATION=$ETCD_DOWNLOAD_URL/$ETCD_VERSION/$ETCD_DOWNLOAD_FILE
 # etcd is always required, so place it into list of pre-cached downloads
 EXTRA_CACHE_URLS+=",$ETCD_DOWNLOAD_LOCATION"
 
+# Cache settings
+CACHE_BACKEND=${CACHE_BACKEND:-"dogpile.cache.memcached"}
+MEMCACHE_SERVERS=${MEMCACHE_SERVERS:-"localhost:11211"}
+
 # Detect duplicate values in IMAGE_URLS
 for image_url in ${IMAGE_URLS//,/ }; do
     if [ $(echo "$IMAGE_URLS" | grep -o -F "$image_url" | wc -l) -gt 1 ]; then