task_flow: Ensure backend package is installed

The octavia pacakge in Ubuntu/Debian does not install python3-redis
automatically and it should be additionally installed. Also the octavia
package in RDO is removing explicit dependency to python3-redis[1] so
the package needs to be additionally installed in RDO in the future.

[1] https://review.rdoproject.org/r/c/openstack/octavia-distgit/+/53067

Change-Id: Ie7ffa7e22848a3f888a1a553aa26f2e4171a191b

manifests/params.pp

@@ -23,6 +23,8 @@ class octavia::params {
       $driver_agent_package_name   = 'openstack-octavia-driver-agent'
       $octavia_wsgi_script_path    = '/var/www/cgi-bin/octavia'
       $octavia_wsgi_script_source  = '/usr/bin/octavia-wsgi'
+      $python_redis_package_name   = 'python3-redis'
+      $python_kazoo_package_name   = 'python3-kazoo'
     }
     'Debian': {
       $common_package_name         = 'octavia-common'
@@ -33,6 +35,8 @@ class octavia::params {
       $driver_agent_package_name   = 'octavia-driver-agent'
       $octavia_wsgi_script_path    = '/usr/lib/cgi-bin/octavia'
       $octavia_wsgi_script_source  = '/usr/bin/octavia-wsgi'
+      $python_redis_package_name   = 'python3-redis'
+      $python_kazoo_package_name   = 'python3-kazoo'
     }
     default: {
       fail("Unsupported osfamily: ${facts['os']['family']}")

manifests/task_flow.pp

@@ -69,6 +69,14 @@
 #   (optional) Url used to connect to the persistence database.
 #   Defaults to $facts['os_service_default']
 #
+# [*manage_backend_package*]
+#   (Optional) Whether to install the backend package.
+#   Defaults to true.
+#
+# [*package_ensure*]
+#   (Optional) ensure state for package.
+#   Defaults to 'present'
+#
 class octavia::task_flow (
   $engine                             = $facts['os_service_default'],
   $max_workers                        = $facts['os_service_default'],
@@ -86,9 +94,12 @@ class octavia::task_flow (
   $jobboard_expiration_time           = $facts['os_service_default'],
   $jobboard_save_logbook              = $facts['os_service_default'],
   $persistence_connection             = $facts['os_service_default'],
+  Boolean $manage_backend_package     = true,
+  $package_ensure                     = 'present',
 ) {
 
   include octavia::deps
+  include octavia::params
 
   $jobboard_redis_backend_ssl_options_real = $jobboard_redis_backend_ssl_options ? {
     Hash    => join(join_keys_to_values($jobboard_redis_backend_ssl_options, ':'), ','),
@@ -99,6 +110,39 @@ class octavia::task_flow (
     default => join(any2array($jobboard_zookeeper_ssl_options), ','),
   }
 
+  if $manage_backend_package {
+    $jobboard_backend_driver_real = is_service_default($jobboard_backend_driver) ? {
+      true    => 'redis_taskflow_driver',
+      default => $jobboard_backend_driver,
+    }
+
+    case $jobboard_backend_driver_real {
+      'zookeeper_taskflow_driver': {
+        ensure_packages('python-kazoo', {
+          name   => $::octavia::params::python_kazoo_package_name,
+          ensure => $package_ensure,
+          tag    => ['openstack'],
+        })
+        Anchor['octavia::install::begin']
+        -> Package['python-kazoo']
+        -> Anchor['octavia::install::end']
+      }
+      'redis_taskflow_driver': {
+        ensure_packages('python-redis', {
+          name   => $::octavia::params::python_redis_package_name,
+          ensure => $package_ensure,
+          tag    => ['openstack'],
+        })
+        Anchor['octavia::install::begin']
+        -> Package['python-redis']
+        -> Anchor['octavia::install::end']
+      }
+      default: {
+        fail('unsupported taskflow backend')
+      }
+    }
+  }
+
   octavia_config {
     'task_flow/engine'                             : value => $engine;
     'task_flow/max_workers'                        : value => $max_workers;

releasenotes/notes/task_flow-backend_package-390484b756669544.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    The ``octavia::task_flow`` class now ensures the backend package is
+    installed. Package management can be disabled by setting the new
+    ``manage_backend_package`` parameter to ``false``. The package status
+    can be customized by the new ``package_ensure`` parameter.

spec/classes/octavia_task_flow_spec.rb

@@ -3,7 +3,7 @@ require 'spec_helper'
 describe 'octavia::task_flow' do
   shared_examples 'octavia::task_flow' do
     context 'with default parameters' do
-      it {
+      it 'configures the default values' do
         should contain_octavia_config('task_flow/engine').with_value('<SERVICE DEFAULT>')
         should contain_octavia_config('task_flow/max_workers').with_value('<SERVICE DEFAULT>')
         should contain_octavia_config('task_flow/disable_revert').with_value('<SERVICE DEFAULT>')
@@ -20,7 +20,19 @@ describe 'octavia::task_flow' do
         should contain_octavia_config('task_flow/jobboard_expiration_time').with_value('<SERVICE DEFAULT>')
         should contain_octavia_config('task_flow/jobboard_save_logbook').with_value('<SERVICE DEFAULT>')
         should contain_octavia_config('task_flow/persistence_connection').with_value('<SERVICE DEFAULT>')
-      }
+      end
+
+      it 'should install python-redis' do
+        should contain_package('python-redis').with(
+          :ensure => 'installed',
+          :name   => platform_params[:python_redis_package_name],
+          :tag    => ['openstack'],
+        )
+      end
+
+      it 'should not install python-kazoo' do
+        should_not contain_package('python-kazoo')
+      end
     end
 
     context 'with specified parameters' do
@@ -45,7 +57,7 @@ describe 'octavia::task_flow' do
         }
       end
 
-      it {
+      it 'configures the given values' do
         should contain_octavia_config('task_flow/engine').with_value('parallel')
         should contain_octavia_config('task_flow/max_workers').with_value(5)
         should contain_octavia_config('task_flow/disable_revert').with_value(false)
@@ -62,7 +74,39 @@ describe 'octavia::task_flow' do
         should contain_octavia_config('task_flow/jobboard_expiration_time').with_value(30)
         should contain_octavia_config('task_flow/jobboard_save_logbook').with_value(false)
         should contain_octavia_config('task_flow/persistence_connection').with_value('sqlite://')
-      }
+      end
+
+      it 'should install python-redis' do
+        should contain_package('python-redis').with(
+          :ensure => 'installed',
+          :name   => platform_params[:python_redis_package_name],
+          :tag    => ['openstack'],
+        )
+      end
+
+      it 'should not install python-kazoo' do
+        should_not contain_package('python-kazoo')
+      end
+    end
+
+    context 'with zookeeper driver' do
+      let :params do
+        {
+          :jobboard_backend_driver => 'zookeeper_taskflow_driver',
+        }
+      end
+
+      it 'should not install python-redis' do
+        should_not contain_package('python-redis')
+      end
+
+      it 'should install python-kazoo' do
+        should contain_package('python-kazoo').with(
+          :ensure => 'installed',
+          :name   => platform_params[:python_kazoo_package_name],
+          :tag    => ['openstack'],
+        )
+      end
     end
 
     context 'with ssl options set to dict' do
@@ -94,6 +138,21 @@ describe 'octavia::task_flow' do
         facts.merge(OSDefaults.get_facts())
       end
 
+      let(:platform_params) do
+        case facts[:os]['family']
+        when 'Debian'
+          {
+            :python_redis_package_name => 'python3-redis',
+            :python_kazoo_package_name => 'python3-kazoo'
+          }
+        when 'RedHat'
+          {
+            :python_redis_package_name => 'python3-redis',
+            :python_kazoo_package_name => 'python3-kazoo'
+          }
+        end
+      end
+
       it_behaves_like 'octavia::task_flow'
     end
   end