Updates

ETB-API/venv/lib/python3.12/site-packages/django_prometheus/migrations.py

@@ -0,0 +1,50 @@
+from django.db import connections
+from django.db.backends.dummy.base import DatabaseWrapper
+from prometheus_client import Gauge
+
+from django_prometheus.conf import NAMESPACE
+
+unapplied_migrations = Gauge(
+    "django_migrations_unapplied_total",
+    "Count of unapplied migrations by database connection",
+    ["connection"],
+    namespace=NAMESPACE,
+)
+
+applied_migrations = Gauge(
+    "django_migrations_applied_total",
+    "Count of applied migrations by database connection",
+    ["connection"],
+    namespace=NAMESPACE,
+)
+
+
+def ExportMigrationsForDatabase(alias, executor):
+    plan = executor.migration_plan(executor.loader.graph.leaf_nodes())
+    unapplied_migrations.labels(alias).set(len(plan))
+    applied_migrations.labels(alias).set(len(executor.loader.applied_migrations))
+
+
+def ExportMigrations():
+    """Exports counts of unapplied migrations.
+
+    This is meant to be called during app startup, ideally by
+    django_prometheus.apps.AppConfig.
+    """
+    # Import MigrationExecutor lazily. MigrationExecutor checks at
+    # import time that the apps are ready, and they are not when
+    # django_prometheus is imported. ExportMigrations() should be
+    # called in AppConfig.ready(), which signals that all apps are
+    # ready.
+    from django.db.migrations.executor import MigrationExecutor
+
+    if "default" in connections and (isinstance(connections["default"], DatabaseWrapper)):
+        # This is the case where DATABASES = {} in the configuration,
+        # i.e. the user is not using any databases. Django "helpfully"
+        # adds a dummy database and then throws when you try to
+        # actually use it. So we don't do anything, because trying to
+        # export stats would crash the app on startup.
+        return
+    for alias in connections.databases:
+        executor = MigrationExecutor(connections[alias])
+        ExportMigrationsForDatabase(alias, executor)