Install python-redis when coordination is set

Without this redis can be missing when needed and cause
metricd to go nuts.

Change-Id: I5aa394f25f8c7b0f733868eb4389acda26333132

manifests/params.pp

@@ -23,6 +23,7 @@ class gnocchi::params {
       $gnocchi_wsgi_script_source = '/usr/lib/python2.7/site-packages/gnocchi/rest/app.wsgi'
       $pymysql_package_name       = undef
       $cradox_package_name        = 'python2-cradox'
+      $redis_package_name         = 'python-redis'
     }
     'Debian': {
       $sqlite_package_name        = 'python-pysqlite2'
@@ -37,6 +38,7 @@ class gnocchi::params {
       $gnocchi_wsgi_script_path   = '/usr/lib/cgi-bin/gnocchi'
       $gnocchi_wsgi_script_source = '/usr/share/gnocchi-common/app.wsgi'
       $pymysql_package_name       = 'python-pymysql'
+      $redis_package_name         = 'python-redis'
       $cradox_package_name        = undef
     }
     default: {

manifests/storage.pp

@@ -32,8 +32,17 @@ class gnocchi::storage(
 
   include ::gnocchi::deps
 
-  gnocchi_config {
-    'storage/coordination_url' : value => $coordination_url;
-  }
+  if $coordination_url {
 
+    gnocchi_config {
+      'storage/coordination_url' : value => $coordination_url;
+    }
+
+    if ($coordination_url =~ /^redis/ ) {
+      ensure_resource('package', 'python-redis', {
+        name   => $::gnocchi::params::redis_package_name,
+        tag    => 'openstack',
+      })
+    }
+  }
 }

releasenotes/notes/install-redis-ded395c27ee7dfc3.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - Install redis when coordination is set in gnocchi storage.
+    Otherwise metricd will go creazy and throw exceptions.

spec/classes/gnocchi_storage_spec.rb

@@ -19,6 +19,13 @@ describe 'gnocchi::storage' do
       it 'configures backend_url' do
         is_expected.to contain_gnocchi_config('storage/coordination_url').with_value('redis://localhost:6379')
       end
+
+      it 'installs python-redis package' do
+         is_expected.to contain_package(platform_params[:redis_package_name]).with(
+           :name => platform_params[:redis_package_name],
+           :tag  => 'openstack'
+         )
+      end
     end
   end
 
@@ -30,6 +37,15 @@ describe 'gnocchi::storage' do
         facts.merge!(OSDefaults.get_facts())
       end
 
+      let(:platform_params) do
+         case facts[:osfamily]
+         when 'Debian'
+           { :redis_package_name     => 'python-redis' }
+         when 'RedHat'
+           { :redis_package_name     => 'python-redis' }
+         end
+       end
+
       it_behaves_like 'gnocchi-storage'
     end
   end