Add ConfigurationModel governing integration with the catalog service.

This is the first in a series of commits that will retrieve and use data from the catalog API. Part of ECOM-4566.

cms/envs/common.py

@@ -898,6 +898,9 @@ INSTALLED_APPS = (
     # programs support
     'openedx.core.djangoapps.programs',
 
+    # Catalog integration
+    'openedx.core.djangoapps.catalog',
+
     # Self-paced course configuration
     'openedx.core.djangoapps.self_paced',
 

lms/envs/common.py

@@ -2039,6 +2039,9 @@ INSTALLED_APPS = (
     # programs support
     'openedx.core.djangoapps.programs',
 
+    # Catalog integration
+    'openedx.core.djangoapps.catalog',
+
     # Self-paced course configuration
     'openedx.core.djangoapps.self_paced',
 

openedx/core/djangoapps/catalog/migrations/0001_initial.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+from django.conf import settings
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='CatalogIntegration',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('change_date', models.DateTimeField(auto_now_add=True, verbose_name='Change date')),
+                ('enabled', models.BooleanField(default=False, verbose_name='Enabled')),
+                ('internal_api_url', models.URLField(help_text='API root to be used for server-to-server requests (e.g., https://catalog-internal.example.com/api/v1/).', verbose_name='Internal API URL')),
+                ('cache_ttl', models.PositiveIntegerField(default=0, help_text='Specified in seconds. Enable caching of API responses by setting this to a value greater than 0.', verbose_name='Cache Time To Live')),
+                ('changed_by', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, editable=False, to=settings.AUTH_USER_MODEL, null=True, verbose_name='Changed by')),
+            ],
+            options={
+                'ordering': ('-change_date',),
+                'abstract': False,
+            },
+        ),
+    ]

openedx/core/djangoapps/catalog/models.py

@@ -0,0 +1,34 @@
+"""Models governing integration with the catalog service."""
+from django.utils.translation import ugettext_lazy as _
+from django.db import models
+
+from config_models.models import ConfigurationModel
+
+
+class CatalogIntegration(ConfigurationModel):
+    """Manages configuration for connecting to the catalog service and using its API."""
+    API_NAME = 'catalog'
+    CACHE_KEY = 'catalog.api.data'
+
+    internal_api_url = models.URLField(
+        verbose_name=_('Internal API URL'),
+        help_text=_(
+            'API root to be used for server-to-server requests (e.g., https://catalog-internal.example.com/api/v1/).'
+        )
+    )
+
+    cache_ttl = models.PositiveIntegerField(
+        verbose_name=_('Cache Time To Live'),
+        default=0,
+        help_text=_(
+            'Specified in seconds. Enable caching of API responses by setting this to a value greater than 0.'
+        )
+    )
+
+    @property
+    def is_cache_enabled(self):
+        """Whether responses from the catalog API will be cached."""
+        return self.cache_ttl > 0
+
+    def __unicode__(self):
+        return self.internal_api_url

openedx/core/djangoapps/catalog/tests/mixins.py

@@ -0,0 +1,19 @@
+"""Mixins to help test catalog integration."""
+from openedx.core.djangoapps.catalog.models import CatalogIntegration
+
+
+class CatalogIntegrationMixin(object):
+    """Utility for working with the catalog service during testing."""
+
+    DEFAULTS = {
+        'enabled': True,
+        'internal_api_url': 'https://catalog-internal.example.com/api/v1/',
+        'cache_ttl': 0,
+    }
+
+    def create_catalog_integration(self, **kwargs):
+        """Creates a new CatalogIntegration with DEFAULTS, updated with any provided overrides."""
+        fields = dict(self.DEFAULTS, **kwargs)
+        CatalogIntegration(**fields).save()
+
+        return CatalogIntegration.current()

openedx/core/djangoapps/catalog/tests/test_models.py

@@ -0,0 +1,23 @@
+"""Catalog model tests."""
+import ddt
+from django.test import TestCase
+import mock
+
+from openedx.core.djangoapps.catalog.tests import mixins
+
+
+@ddt.ddt
+# ConfigurationModels use the cache. Make every cache get a miss.
+@mock.patch('config_models.models.cache.get', return_value=None)
+class TestCatalogIntegration(mixins.CatalogIntegrationMixin, TestCase):
+    """Tests covering the CatalogIntegration model."""
+
+    @ddt.data(
+        (0, False),
+        (1, True),
+    )
+    @ddt.unpack
+    def test_cache_control(self, cache_ttl, is_cache_enabled, _mock_cache):
+        """Test the behavior of the property controlling whether API responses are cached."""
+        catalog_integration = self.create_catalog_integration(cache_ttl=cache_ttl)
+        self.assertEqual(catalog_integration.is_cache_enabled, is_cache_enabled)