devstack: support the gnocchi collector

Actually use CLOUDKITTY_COLLECTOR to setup the ceilometer/gnocchi
collectors.

Update the documentation accordingly.

Change-Id: I7308c0597c0ae9dac435cf1c0cc2e3b4c07ba063

devstack/plugin.sh

@@ -114,10 +114,9 @@ function configure_cloudkitty {
 
     iniset $CLOUDKITTY_CONF keystone_fetcher auth_section authinfos
 
-    iniset $CLOUDKITTY_CONF ceilometer_collector auth_section authinfos
-
     # collect
     iniset $CLOUDKITTY_CONF collect collector $CLOUDKITTY_COLLECTOR
+    iniset $CLOUDKITTY_CONF ${CLOUDKITTY_COLLECTOR}_collector auth_section authinfos
     iniset $CLOUDKITTY_CONF collect services $CLOUDKITTY_SERVICES
 
     # output

doc/source/devstack.rst

@@ -2,8 +2,8 @@
 DevStack installation
 #####################
 
-The installation of CloudKitty from DevStack is pretty straightforward. Just
-add the following lines to your local.conf file.
+Add the following lines in your ``local.conf`` file to enable CloudKitty with
+the ceilometer collector:
 
 ::
 
@@ -17,8 +17,31 @@ add the following lines to your local.conf file.
     # cloudkitty
     enable_plugin cloudkitty https://git.openstack.org/openstack/cloudkitty.git master
     enable_service ck-api ck-proc
+    CLOUDKITTY_COLLECTOR=ceilometer
 
-Then, you can start devstack.
+
+To enable the gnocchi collector, use the following instead:
+
+::
+
+    [[local|localrc]]
+    # gnocchi
+    enable_plugin gnocchi https://github.com/openstack/gnocchi master
+    enable_service gnocchi-api,gnocchi-metricd
+
+    # ceilometer
+    enable_plugin ceilometer https://git.openstack.org/openstack/ceilometer.git master
+
+    # horizon
+    enable_service horizon
+
+    # cloudkitty
+    enable_plugin cloudkitty https://git.openstack.org/openstack/cloudkitty.git master
+    enable_service ck-api ck-proc
+    CLOUDKITTY_COLLECTOR=gnocchi
+
+
+Then start devstack:
 
 ::