Domains: put a limit of 2 custom domains per project (#11629)

* Domains: put a limit of 2 custom domains per project

Related #1808

* Domains: add tests for limit amount of domains

* Add missing import

* Test: define 2 domains as limit for all the tests

readthedocs/domains/validators.py

@@ -0,0 +1,25 @@
+from django.conf import settings
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _
+
+from readthedocs.subscriptions.constants import TYPE_CNAME
+from readthedocs.subscriptions.products import get_feature
+
+
+def check_domains_limit(project, error_class=ValidationError):
+    """Check if the project has reached the limit on the number of domains."""
+    feature = get_feature(project, TYPE_CNAME)
+    if feature.unlimited:
+        return
+
+    if project.domains.count() >= feature.value:
+        msg = _(
+            f"This project has reached the limit of {feature.value} domains."
+            " Consider removing unused domains."
+        )
+        if settings.ALLOW_PRIVATE_REPOS:
+            msg = _(
+                f"Your organization has reached the limit of {feature.value} domains."
+                " Consider removing unused domains or upgrading your plan."
+            )
+        raise error_class(msg)

readthedocs/projects/models.py

@@ -36,6 +36,7 @@
 from readthedocs.core.utils import extract_valid_attributes_for_model, slugify
 from readthedocs.core.utils.url import unsafe_join_url_path
 from readthedocs.domains.querysets import DomainQueryset
+from readthedocs.domains.validators import check_domains_limit
 from readthedocs.notifications.models import Notification as NewNotification
 from readthedocs.projects import constants
 from readthedocs.projects.exceptions import ProjectConfigurationError
@@ -1809,6 +1810,9 @@ def restart_validation_process(self):
             self.validation_process_start = timezone.now()
             self.save()
 
+    def clean(self):
+        check_domains_limit(self.project)
+
     def save(self, *args, **kwargs):
         parsed = urlparse(self.domain)
         if parsed.scheme or parsed.netloc:

readthedocs/projects/tests/test_domain_views.py

@@ -12,7 +12,7 @@
 
 @override_settings(
     RTD_ALLOW_ORGANIZATIONS=False,
-    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME).to_item()]),
+    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]),
 )
 class TestDomainViews(TestCase):
     def setUp(self):

readthedocs/proxito/tests/test_full.py

@@ -1725,7 +1725,7 @@ def test_404_download(self):
     ALLOW_PRIVATE_REPOS=True,
     PUBLIC_DOMAIN="dev.readthedocs.io",
     PUBLIC_DOMAIN_USES_HTTPS=True,
-    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME).to_item()]),
+    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]),
 )
 # We are overriding the storage class instead of using RTD_BUILD_MEDIA_STORAGE,
 # since the setting is evaluated just once (first test to use the storage

readthedocs/proxito/tests/test_middleware.py

@@ -21,7 +21,7 @@
 @pytest.mark.proxito
 @override_settings(
     PUBLIC_DOMAIN="dev.readthedocs.io",
-    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME).to_item()]),
+    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]),
 )
 class MiddlewareTests(RequestFactoryTestMixin, TestCase):
     def setUp(self):

readthedocs/proxito/tests/test_redirects.py

@@ -15,7 +15,7 @@
     PUBLIC_DOMAIN="dev.readthedocs.io",
     RTD_EXTERNAL_VERSION_DOMAIN="dev.readthedocs.build",
     PUBLIC_DOMAIN_USES_HTTPS=True,
-    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME).to_item()]),
+    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]),
 )
 class RedirectTests(BaseDocServing):
     def test_root_url_no_slash(self):

readthedocs/rtd_tests/tests/test_domains.py

@@ -4,6 +4,8 @@
 
 from readthedocs.projects.forms import DomainForm
 from readthedocs.projects.models import Domain, Project
+from readthedocs.subscriptions.constants import TYPE_CNAME
+from readthedocs.subscriptions.products import RTDProductFeature, get_feature
 
 
 class ModelTests(TestCase):
@@ -205,3 +207,53 @@ def test_dont_allow_changin_https_to_http(self):
         self.assertTrue(form.is_valid())
         domain = form.save()
         self.assertTrue(domain.https)
+
+    @override_settings(
+        RTD_DEFAULT_FEATURES=dict(
+            [RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]
+        ),
+    )
+    def test_domains_limit(self):
+        feature = get_feature(self.project, TYPE_CNAME)
+        form = DomainForm(
+            {
+                "domain": "docs.user.example.com",
+                "canonical": True,
+            },
+            project=self.project,
+        )
+        self.assertTrue(form.is_valid())
+        form.save()
+        self.assertEqual(self.project.domains.all().count(), 1)
+
+        form = DomainForm(
+            {
+                "domain": "docs.dev.example.com",
+                "canonical": False,
+            },
+            project=self.project,
+        )
+        self.assertTrue(form.is_valid())
+        form.save()
+        self.assertEqual(self.project.domains.all().count(), 2)
+
+        # Creating the third (3) domain should fail the validation form
+        form = DomainForm(
+            {
+                "domain": "docs.customer.example.com",
+                "canonical": False,
+            },
+            project=self.project,
+        )
+        self.assertFalse(form.is_valid())
+
+        msg = (
+            f"This project has reached the limit of {feature.value} domains. "
+            "Consider removing unused domains."
+        )
+        if settings.RTD_ALLOW_ORGANIZATIONS:
+            msg = (
+                f"Your organization has reached the limit of {feature.value} domains. "
+                "Consider removing unused domains or upgrading your plan."
+            )
+        self.assertEqual(form.errors["__all__"][0], msg)

readthedocs/rtd_tests/tests/test_footer.py

@@ -479,7 +479,7 @@ def test_private_highest_version(self):
 @pytest.mark.proxito
 @override_settings(
     PUBLIC_DOMAIN="readthedocs.io",
-    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME).to_item()]),
+    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]),
 )
 class TestFooterPerformance(TestCase):
     # The expected number of queries for generating the footer

readthedocs/rtd_tests/tests/test_resolver.py

@@ -20,7 +20,7 @@
 
 @override_settings(
     PUBLIC_DOMAIN="readthedocs.org",
-    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME).to_item()]),
+    RTD_DEFAULT_FEATURES=dict([RTDProductFeature(type=TYPE_CNAME, value=2).to_item()]),
 )
 class ResolverBase(TestCase):
     def setUp(self):

readthedocs/settings/base.py

@@ -170,7 +170,8 @@ def RTD_DEFAULT_FEATURES(self):
 
         return dict(
             (
-                RTDProductFeature(type=constants.TYPE_CNAME).to_item(),
+                # Max number of domains allowed per project.
+                RTDProductFeature(type=constants.TYPE_CNAME, value=2).to_item(),
                 RTDProductFeature(type=constants.TYPE_EMBED_API).to_item(),
                 # Retention days for search analytics.
                 RTDProductFeature(