fix(uptime): Enforce domain limits everywhere

Currently we're only enforcing these at the api level. Move them to autodetection as well, and add an index to make sure we can still query them cheaply.

migrations_lockfile.txt

@@ -21,6 +21,6 @@ social_auth: 0002_default_auto_field
 
 tempest: 0002_make_message_type_nullable
 
-uptime: 0026_region_mode_col
+uptime: 0027_uptime_subscription_index_domain_cols
 
 workflow_engine: 0032_remove_data_source_query_id

src/sentry/uptime/detectors/ranking.py

@@ -10,7 +10,11 @@
 
 from sentry.constants import UPTIME_AUTODETECTION
 from sentry.uptime.models import get_active_auto_monitor_count_for_org
-from sentry.uptime.subscriptions.subscriptions import MAX_AUTO_SUBSCRIPTIONS_PER_ORG
+from sentry.uptime.subscriptions.subscriptions import (
+    MAX_AUTO_SUBSCRIPTIONS_PER_ORG,
+    MaxUrlsForDomainReachedException,
+    check_url_limits,
+)
 from sentry.utils import metrics, redis
 
 if TYPE_CHECKING:
@@ -105,14 +109,24 @@ def delete_candidate_projects_for_org(org: Organization) -> None:
     cluster.delete(key)
 
 
-def get_candidate_urls_for_project(project: Project) -> list[tuple[str, int]]:
+def get_candidate_urls_for_project(project: Project, limit=5) -> list[tuple[str, int]]:
     """
     Gets all the candidate urls for a project. Returns a tuple of (url, times_url_seen). Urls are sorted by
     `times_url_seen` desc.
     """
     key = get_project_base_url_rank_key(project)
     cluster = _get_cluster()
-    return cluster.zrange(key, 0, -1, desc=True, withscores=True, score_cast_func=int)
+    candidate_urls = cluster.zrange(key, 0, -1, desc=True, withscores=True, score_cast_func=int)
+    urls = []
+    for candidate_url, url_count in candidate_urls:
+        try:
+            check_url_limits(candidate_url)
+            urls.append((candidate_url, url_count))
+        except MaxUrlsForDomainReachedException:
+            pass
+        if len(urls) == limit:
+            break
+    return urls
 
 
 def delete_candidate_urls_for_project(project: Project) -> None:

src/sentry/uptime/detectors/tasks.py

@@ -146,7 +146,7 @@ def process_project_url_ranking(project: Project, project_url_count: int) -> boo
 
     found_url = False
 
-    for url, url_count in get_candidate_urls_for_project(project)[:5]:
+    for url, url_count in get_candidate_urls_for_project(project, limit=5):
         if process_candidate_url(project, project_url_count, url, url_count):
             found_url = True
             break

src/sentry/uptime/endpoints/validators.py

@@ -11,7 +11,6 @@
 from sentry.auth.superuser import is_active_superuser
 from sentry.constants import ObjectStatus
 from sentry.models.environment import Environment
-from sentry.uptime.detectors.url_extraction import extract_domain_parts
 from sentry.uptime.models import (
     ProjectUptimeSubscription,
     ProjectUptimeSubscriptionMode,
@@ -20,13 +19,14 @@
 from sentry.uptime.subscriptions.subscriptions import (
     MAX_MANUAL_SUBSCRIPTIONS_PER_ORG,
     MaxManualUptimeSubscriptionsReached,
+    MaxUrlsForDomainReachedException,
     UptimeMonitorNoSeatAvailable,
+    check_url_limits,
     create_project_uptime_subscription,
     update_project_uptime_subscription,
 )
 from sentry.utils.audit import create_audit_entry
 
-MAX_MONITORS_PER_DOMAIN = 100
 """
 The bounding upper limit on how many ProjectUptimeSubscription's can exist for
 a single domain + suffix.
@@ -155,15 +155,12 @@ def validate(self, attrs):
         return attrs
 
     def validate_url(self, url):
-        url_parts = extract_domain_parts(url)
-        existing_count = ProjectUptimeSubscription.objects.filter(
-            uptime_subscription__url_domain=url_parts.domain,
-            uptime_subscription__url_domain_suffix=url_parts.suffix,
-        ).count()
-
-        if existing_count >= MAX_MONITORS_PER_DOMAIN:
+        try:
+            check_url_limits(url)
+        except MaxUrlsForDomainReachedException as e:
             raise serializers.ValidationError(
-                f"The domain *.{url_parts.domain}.{url_parts.suffix} has already been used in {MAX_MONITORS_PER_DOMAIN} uptime monitoring alerts, which is the limit. You cannot create any additional alerts for this domain."
+                f"The domain *.{e.domain}.{e.suffix} has already been used in {e.max_urls} uptime monitoring alerts, "
+                "which is the limit. You cannot create any additional alerts for this domain."
             )
         return url
 

src/sentry/uptime/migrations/0027_uptime_subscription_index_domain_cols.py

@@ -0,0 +1,34 @@
+# Generated by Django 5.1.5 on 2025-02-28 00:32
+
+from django.db import migrations, models
+
+from sentry.new_migrations.migrations import CheckedMigration
+
+
+class Migration(CheckedMigration):
+    # This flag is used to mark that a migration shouldn't be automatically run in production.
+    # This should only be used for operations where it's safe to run the migration after your
+    # code has deployed. So this should not be used for most operations that alter the schema
+    # of a table.
+    # Here are some things that make sense to mark as post deployment:
+    # - Large data migrations. Typically we want these to be run manually so that they can be
+    #   monitored and not block the deploy for a long period of time while they run.
+    # - Adding indexes to large tables. Since this can take a long time, we'd generally prefer to
+    #   run this outside deployments so that we don't block them. Note that while adding an index
+    #   is a schema change, it's completely safe to run the operation after the code has deployed.
+    # Once deployed, run these manually via: https://develop.sentry.dev/database-migrations/#migration-deployment
+
+    is_post_deployment = False
+
+    dependencies = [
+        ("uptime", "0026_region_mode_col"),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name="uptimesubscription",
+            index=models.Index(
+                fields=["url_domain_suffix", "url_domain"], name="uptime_upti_url_dom_ead522_idx"
+            ),
+        ),
+    ]

src/sentry/uptime/models.py

@@ -115,6 +115,7 @@ class Meta:
                 name="uptime_uptimesubscription_unique_subscription_check_4",
             ),
         ]
+        indexes = (models.Index(fields=("url_domain_suffix", "url_domain")),)
 
 
 @region_silo_model

src/sentry/uptime/subscriptions/subscriptions.py

@@ -31,6 +31,7 @@
 UPTIME_SUBSCRIPTION_TYPE = "uptime_monitor"
 MAX_AUTO_SUBSCRIPTIONS_PER_ORG = 1
 MAX_MANUAL_SUBSCRIPTIONS_PER_ORG = 100
+MAX_MONITORS_PER_DOMAIN = 100
 
 
 class MaxManualUptimeSubscriptionsReached(ValueError):
@@ -447,3 +448,23 @@ def check_and_update_regions(
                 )
             deleted_region.delete()
     return True
+
+
+class MaxUrlsForDomainReachedException(Exception):
+    def __init__(self, domain, suffix, max_urls):
+        self.domain = domain
+        self.suffix = suffix
+        self.max_urls = max_urls
+
+
+def check_url_limits(url):
+    url_parts = extract_domain_parts(url)
+    existing_count = ProjectUptimeSubscription.objects.filter(
+        uptime_subscription__url_domain=url_parts.domain,
+        uptime_subscription__url_domain_suffix=url_parts.suffix,
+    ).count()
+
+    if existing_count >= MAX_MONITORS_PER_DOMAIN:
+        raise MaxUrlsForDomainReachedException(
+            url_parts.domain, url_parts.suffix, MAX_MONITORS_PER_DOMAIN
+        )

tests/sentry/uptime/detectors/test_ranking.py

@@ -134,6 +134,20 @@ def test(self):
         add_base_url_to_rank(self.project, url_2)
         assert get_candidate_urls_for_project(self.project) == [(url_2, 2), (url_1, 1)]
 
+    def test_limits(self):
+        with mock.patch("sentry.uptime.subscriptions.subscriptions.MAX_MONITORS_PER_DOMAIN", 1):
+            other_proj = self.create_project()
+            url_1 = "https://sentry.io"
+            self.create_project_uptime_subscription(
+                project=other_proj, uptime_subscription=self.create_uptime_subscription(url=url_1)
+            )
+            url_2 = "https://sentry.sentry.io"
+            url_3 = "https://sentry.santry.io"
+            add_base_url_to_rank(self.project, url_1)
+            add_base_url_to_rank(self.project, url_2)
+            add_base_url_to_rank(self.project, url_3)
+            assert get_candidate_urls_for_project(self.project) == [(url_3, 1)]
+
 
 class DeleteCandidateUrlsForProjectTest(UptimeTestCase):
     def test(self):

tests/sentry/uptime/endpoints/test_project_uptime_alert_details.py

@@ -172,7 +172,7 @@ def test_not_found(self):
         resp = self.get_error_response(self.organization.slug, self.project.slug, 3)
         assert resp.status_code == 404
 
-    @mock.patch("sentry.uptime.endpoints.validators.MAX_MONITORS_PER_DOMAIN", 1)
+    @mock.patch("sentry.uptime.subscriptions.subscriptions.MAX_MONITORS_PER_DOMAIN", 1)
     def test_domain_limit(self):
         # First monitor is for test-one.example.com
         self.create_project_uptime_subscription(