Provide form building schema

src/servala/core/forms.py

@@ -1,3 +1,7 @@
+import json
+from pathlib import Path
+
+import jsonschema
 from django import forms
 from django.utils.translation import gettext_lazy as _
 from django_jsonform.widgets import JSONFormWidget
@@ -124,6 +128,10 @@ class ServiceDefinitionAdminForm(forms.ModelForm):
             self.fields["api_version"].initial = api_def.get("version", "")
             self.fields["api_kind"].initial = api_def.get("kind", "")
 
+        schema_path = Path(__file__).parent / "schemas" / "form_config_schema.json"
+        with open(schema_path) as f:
+            self.form_config_schema = json.load(f)
+
     def clean(self):
         cleaned_data = super().clean()
 
@@ -151,6 +159,19 @@ class ServiceDefinitionAdminForm(forms.ModelForm):
                     api_def["kind"] = api_kind
                 cleaned_data["api_definition"] = api_def
 
+        form_config = cleaned_data.get("form_config")
+        if form_config:
+            try:
+                jsonschema.validate(instance=form_config, schema=self.form_config_schema)
+            except jsonschema.ValidationError as e:
+                raise forms.ValidationError(
+                    {"form_config": _("Invalid form configuration: {}").format(e.message)}
+                )
+            except jsonschema.SchemaError as e:
+                raise forms.ValidationError(
+                    {"form_config": _("Schema error: {}").format(e.message)}
+                )
+
         return cleaned_data
 
     def save(self, *args, **kwargs):

src/servala/core/models/service.py

@@ -360,6 +360,16 @@ class ServiceDefinition(ServalaModelMixin, models.Model):
         null=True,
         blank=True,
     )
+    form_config = models.JSONField(
+        verbose_name=_("Form Configuration"),
+        help_text=_(
+            "Optional custom form configuration. When provided, this configuration will be used "
+            "to render the service form instead of auto-generating it from the OpenAPI spec. "
+            "Format: {\"fieldsets\": [{\"title\": \"Section\", \"fields\": [{...}]}]}"
+        ),
+        null=True,
+        blank=True,
+    )
     service = models.ForeignKey(
         to="Service",
         on_delete=models.CASCADE,

src/servala/core/schemas/form_config_schema.json

@@ -0,0 +1,132 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "Service Definition Form Configuration Schema",
+  "description": "Schema for custom form configuration in ServiceDefinition",
+  "type": "object",
+  "required": ["fieldsets"],
+  "properties": {
+    "fieldsets": {
+      "type": "array",
+      "description": "Array of fieldset objects defining form sections",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": ["fields"],
+        "properties": {
+          "title": {
+            "type": "string",
+            "description": "Optional title for the fieldset/tab"
+          },
+          "fields": {
+            "type": "array",
+            "description": "Array of field definitions in this fieldset",
+            "minItems": 1,
+            "items": {
+              "type": "object",
+              "required": ["name", "type", "label", "controlplane_field_mapping"],
+              "properties": {
+                "name": {
+                  "type": "string",
+                  "description": "Unique field name/identifier",
+                  "pattern": "^[a-zA-Z_][a-zA-Z0-9_]*$"
+                },
+                "type": {
+                  "type": "string",
+                  "description": "Field type",
+                  "enum": ["text", "email", "textarea", "number", "choice", "checkbox", "array"]
+                },
+                "label": {
+                  "type": "string",
+                  "description": "Human-readable field label"
+                },
+                "help_text": {
+                  "type": "string",
+                  "description": "Optional help text displayed below the field"
+                },
+                "required": {
+                  "type": "boolean",
+                  "description": "Whether the field is required",
+                  "default": false
+                },
+                "default": {
+                  "description": "Default value for the field"
+                },
+                "controlplane_field_mapping": {
+                  "type": "string",
+                  "description": "Dot-notation path mapping to Kubernetes spec field (e.g., 'spec.parameters.service.fqdn')"
+                },
+                "max_length": {
+                  "type": "integer",
+                  "description": "Maximum length for text/textarea fields",
+                  "minimum": 1
+                },
+                "rows": {
+                  "type": "integer",
+                  "description": "Number of rows for textarea fields",
+                  "minimum": 1
+                },
+                "min_value": {
+                  "type": "number",
+                  "description": "Minimum value for number fields"
+                },
+                "max_value": {
+                  "type": "number",
+                  "description": "Maximum value for number fields"
+                },
+                "choices": {
+                  "type": "array",
+                  "description": "Array of [value, label] pairs for choice fields",
+                  "items": {
+                    "type": "array",
+                    "minItems": 2,
+                    "maxItems": 2,
+                    "items": [
+                      {"type": "string"},
+                      {"type": "string"}
+                    ]
+                  }
+                },
+                "min_values": {
+                  "type": "integer",
+                  "description": "Minimum number of values for array fields",
+                  "minimum": 0
+                },
+                "max_values": {
+                  "type": "integer",
+                  "description": "Maximum number of values for array fields",
+                  "minimum": 1
+                },
+                "validators": {
+                  "type": "array",
+                  "description": "Array of validator names (for future use)",
+                  "items": {
+                    "type": "string",
+                    "enum": ["email", "fqdn", "url", "ipv4", "ipv6"]
+                  }
+                },
+                "generators": {
+                  "type": "array",
+                  "description": "Array of generator function names (for future use)",
+                  "items": {
+                    "type": "string",
+                    "enum": ["suggest_fqdn_from_name"]
+                  }
+                }
+              },
+              "allOf": [
+                {
+                  "if": {
+                    "properties": {"type": {"const": "choice"}}
+                  },
+                  "then": {
+                    "required": ["choices"]
+                  }
+                }
+              ]
+            }
+          }
+        }
+      }
+    }
+  }
+}