ServiceDefinition as part of the through model

src/servala/core/admin.py

@@ -14,6 +14,7 @@ from servala.core.models import (
     ServiceCategory,
     ServiceDefinition,
     ServiceOffering,
+    ServiceOfferingControlPlane,
     User,
 )
 
@@ -176,7 +177,7 @@ class PlanAdmin(admin.ModelAdmin):
 class ServiceDefinitionAdmin(admin.ModelAdmin):
     form = ServiceDefinitionAdminForm
     list_display = ("name", "service")
-    list_filter = ("service", "control_planes")
+    list_filter = ("service",)
     search_fields = ("name", "description")
     autocomplete_fields = ("service",)
 
@@ -199,11 +200,27 @@ class ServiceDefinitionAdmin(admin.ModelAdmin):
         return ["api_definition"]
 
 
+class ServiceOfferingControlPlaneInline(admin.TabularInline):
+    model = ServiceOfferingControlPlane
+    extra = 1
+    autocomplete_fields = ("control_plane", "service_definition")
+
+
+@admin.register(ServiceOfferingControlPlane)
+class ServiceOfferingControlPlaneAdmin(admin.ModelAdmin):
+    list_display = ("service_offering", "control_plane", "service_definition")
+    list_filter = ("service_offering", "control_plane", "service_definition")
+    search_fields = ("service_offering__service__name", "control_plane__name")
+    autocomplete_fields = ("service_offering", "control_plane", "service_definition")
+
+
 @admin.register(ServiceOffering)
 class ServiceOfferingAdmin(admin.ModelAdmin):
     list_display = ("id", "service", "provider")
-    list_filter = ("service", "provider", "control_planes")
+    list_filter = ("service", "provider")
     search_fields = ("description",)
     autocomplete_fields = ("service", "provider")
-    filter_horizontal = ("control_planes",)
+    inlines = (
-    inlines = (PlanInline,)
+        ServiceOfferingControlPlaneInline,
+        PlanInline,
+    )

src/servala/core/migrations/0007_service_definition.py

@@ -0,0 +1,115 @@
+# Generated by Django 5.2b1 on 2025-03-25 11:02
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("core", "0006_service_slug"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="serviceoffering",
+            name="control_plane",
+        ),
+        migrations.CreateModel(
+            name="ServiceDefinition",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("name", models.CharField(max_length=100, verbose_name="Name")),
+                (
+                    "description",
+                    models.TextField(blank=True, verbose_name="Description"),
+                ),
+                (
+                    "api_definition",
+                    models.JSONField(
+                        blank=True,
+                        help_text="Contains group, version, and kind information",
+                        null=True,
+                        verbose_name="API Definition",
+                    ),
+                ),
+                (
+                    "service",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="service_definitions",
+                        to="core.service",
+                        verbose_name="Service",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "Service definition",
+                "verbose_name_plural": "Service definitions",
+            },
+        ),
+        migrations.CreateModel(
+            name="ServiceOfferingControlPlane",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "control_plane",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="offering_connections",
+                        to="core.controlplane",
+                        verbose_name="Control plane",
+                    ),
+                ),
+                (
+                    "service_definition",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="offering_control_planes",
+                        to="core.servicedefinition",
+                        verbose_name="Service definition",
+                    ),
+                ),
+                (
+                    "service_offering",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="control_plane_connections",
+                        to="core.serviceoffering",
+                        verbose_name="Service offering",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "Service offering control plane connection",
+                "verbose_name_plural": "Service offering control planes connections",
+                "unique_together": {("service_offering", "control_plane")},
+            },
+        ),
+        migrations.AddField(
+            model_name="serviceoffering",
+            name="control_planes",
+            field=models.ManyToManyField(
+                related_name="offerings",
+                through="core.ServiceOfferingControlPlane",
+                to="core.controlplane",
+                verbose_name="Control planes",
+            ),
+        ),
+    ]

src/servala/core/migrations/0007_service_definitions.py

@@ -1,72 +0,0 @@
-# Generated by Django 5.2b1 on 2025-03-24 14:41
-
-import django.db.models.deletion
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ("core", "0006_service_slug"),
-    ]
-
-    operations = [
-        migrations.RenameField(
-            model_name="serviceoffering",
-            old_name="control_plane",
-            new_name="control_planes",
-        ),
-        migrations.CreateModel(
-            name="ServiceDefinition",
-            fields=[
-                (
-                    "id",
-                    models.BigAutoField(
-                        auto_created=True,
-                        primary_key=True,
-                        serialize=False,
-                        verbose_name="ID",
-                    ),
-                ),
-                ("name", models.CharField(max_length=100, verbose_name="Name")),
-                (
-                    "description",
-                    models.TextField(blank=True, verbose_name="Description"),
-                ),
-                (
-                    "api_definition",
-                    models.JSONField(
-                        blank=True,
-                        help_text="Contains group, version, and kind information",
-                        null=True,
-                        verbose_name="API Definition",
-                    ),
-                ),
-                (
-                    "service",
-                    models.ForeignKey(
-                        on_delete=django.db.models.deletion.CASCADE,
-                        related_name="service_definitions",
-                        to="core.service",
-                        verbose_name="Service",
-                    ),
-                ),
-            ],
-            options={
-                "verbose_name": "Service definition",
-                "verbose_name_plural": "Service definitions",
-            },
-        ),
-        migrations.AddField(
-            model_name="controlplane",
-            name="service_definition",
-            field=models.ForeignKey(
-                default=1,
-                on_delete=django.db.models.deletion.PROTECT,
-                related_name="control_planes",
-                to="core.servicedefinition",
-                verbose_name="Service definition",
-            ),
-            preserve_default=False,
-        ),
-    ]

src/servala/core/models/__init__.py

@@ -13,6 +13,7 @@ from .service import (
     ServiceCategory,
     ServiceDefinition,
     ServiceOffering,
+    ServiceOfferingControlPlane,
 )
 from .user import User
 
@@ -29,5 +30,6 @@ __all__ = [
     "ServiceCategory",
     "ServiceDefinition",
     "ServiceOffering",
+    "ServiceOfferingControlPlane",
     "User",
 ]

src/servala/core/models/service.py

@@ -103,12 +103,6 @@ class ControlPlane(models.Model):
         related_name="control_planes",
         verbose_name=_("Cloud provider"),
     )
-    service_definition = models.ForeignKey(
-        to="ServiceDefinition",
-        related_name="control_planes",
-        verbose_name=_("Service definition"),
-        on_delete=models.PROTECT,
-    )
 
     class Meta:
         verbose_name = _("Control plane")
@@ -263,6 +257,18 @@ class ServiceDefinition(models.Model):
         verbose_name=_("Service"),
     )
 
+    @property
+    def control_planes(self):
+        return ControlPlane.objects.filter(
+            offering_connections__service_definition=self
+        ).distinct()
+
+    @property
+    def service_offerings(self):
+        return ServiceOffering.objects.filter(
+            control_plane_connections__service_definition=self
+        ).distinct()
+
     class Meta:
         verbose_name = _("Service definition")
         verbose_name_plural = _("Service definitions")
@@ -271,6 +277,40 @@ class ServiceDefinition(models.Model):
         return self.name
 
 
+class ServiceOfferingControlPlane(models.Model):
+    """
+    Each combination of ServiceOffering and ControlPlane can have a different
+    ServiceDefinition, which is here modeled as the "through" model.
+    """
+
+    service_offering = models.ForeignKey(
+        to="ServiceOffering",
+        on_delete=models.CASCADE,
+        related_name="control_plane_connections",
+        verbose_name=_("Service offering"),
+    )
+    control_plane = models.ForeignKey(
+        to="ControlPlane",
+        on_delete=models.CASCADE,
+        related_name="offering_connections",
+        verbose_name=_("Control plane"),
+    )
+    service_definition = models.ForeignKey(
+        to="ServiceDefinition",
+        on_delete=models.PROTECT,
+        related_name="offering_control_planes",
+        verbose_name=_("Service definition"),
+    )
+
+    class Meta:
+        verbose_name = _("Service offering control plane connection")
+        verbose_name_plural = _("Service offering control planes connections")
+        unique_together = [("service_offering", "control_plane")]
+
+    def __str__(self):
+        return f"{self.service_offering} on {self.control_plane} with {self.service_definition}"
+
+
 class ServiceOffering(models.Model):
     """
     A service offering, e.g. "PostgreSQL on AWS", "MinIO on GCP".
@@ -290,6 +330,7 @@ class ServiceOffering(models.Model):
     )
     control_planes = models.ManyToManyField(
         to="ControlPlane",
+        through="ServiceOfferingControlPlane",
         related_name="offerings",
         verbose_name=_("Control planes"),
     )