Implement default values in custom forms

src/servala/core/crd/__init__.py

@@ -0,0 +1,31 @@
+from servala.core.crd.forms import (
+    CrdModelFormMixin,
+    CustomFormMixin,
+    FormGeneratorMixin,
+    generate_custom_form_class,
+    generate_model_form_class,
+)
+from servala.core.crd.models import (
+    CRDModel,
+    build_object_fields,
+    duplicate_field,
+    generate_django_model,
+    get_django_field,
+    unnest_data,
+)
+from servala.core.crd.utils import deslugify
+
+__all__ = [
+    "CrdModelFormMixin",
+    "CustomFormMixin",
+    "FormGeneratorMixin",
+    "generate_django_model",
+    "generate_model_form_class",
+    "generate_custom_form_class",
+    "CRDModel",
+    "build_object_fields",
+    "duplicate_field",
+    "get_django_field",
+    "unnest_data",
+    "deslugify",
+]

src/servala/core/crd/forms.py

@@ -1,291 +1,18 @@
-import re
-
 from django import forms
-from django.core.validators import MaxValueValidator, MinValueValidator, RegexValidator
+from django.core.validators import MaxValueValidator, MinValueValidator
-from django.db import models
 from django.forms.models import ModelForm, ModelFormMetaclass
-from django.utils.translation import gettext_lazy as _
 
-from servala.core.models import ControlPlaneCRD, ServiceInstance
+from servala.core.crd.utils import deslugify
-from servala.frontend.forms.widgets import DynamicArrayField, DynamicArrayWidget
+from servala.core.models import ControlPlaneCRD
-
+from servala.frontend.forms.widgets import DynamicArrayWidget
-
-class CRDModel(models.Model):
-    """Base class for all virtual CRD models"""
-
-    def __init__(self, **kwargs):
-        if spec := kwargs.pop("spec", None):
-            kwargs.update(unnest_data({"spec": spec}))
-        super().__init__(**kwargs)
-
-    class Meta:
-        abstract = True
-
-
-def duplicate_field(field_name, model):
-    field = model._meta.get_field(field_name)
-    new_field = type(field).__new__(type(field))
-    new_field.__dict__.update(field.__dict__)
-    new_field.model = None
-    new_field.auto_created = False
-    return new_field
-
-
-def generate_django_model(schema, group, version, kind):
-    """
-    Generates a virtual Django model from a Kubernetes CRD's OpenAPI v3 schema.
-    """
-    # We always need these three fields to know our own name and our full namespace
-    model_fields = {"__module__": "crd_models"}
-    for field_name in ("name", "context"):
-        model_fields[field_name] = duplicate_field(field_name, ServiceInstance)
-
-    # All other fields are generated from the schema, except for the
-    # resourceRef object
-    spec = schema["properties"].get("spec") or {}
-    spec["properties"].pop("resourceRef", None)
-    model_fields.update(build_object_fields(spec, "spec", parent_required=False))
-
-    # Store the original schema on the model class
-    model_fields["SCHEMA"] = schema
-
-    meta_class = type("Meta", (), {"app_label": "crd_models"})
-    model_fields["Meta"] = meta_class
-
-    # create the model class
-    model_name = kind
-    model_class = type(model_name, (CRDModel,), model_fields)
-    return model_class
-
-
-def build_object_fields(schema, name, verbose_name_prefix=None, parent_required=False):
-    required_fields = schema.get("required") or []
-    properties = schema.get("properties") or {}
-    fields = {}
-
-    for field_name, field_schema in properties.items():
-        is_required = field_name in required_fields or parent_required
-        full_name = f"{name}.{field_name}"
-        result = get_django_field(
-            field_schema,
-            is_required,
-            field_name,
-            full_name,
-            verbose_name_prefix=verbose_name_prefix,
-        )
-        if isinstance(result, dict):
-            fields.update(result)
-        else:
-            fields[full_name] = result
-    return fields
-
-
-def deslugify(title):
-    """
-    Convert camelCase, PascalCase, or snake_case to human-readable title.
-    Handles known acronyms (e.g., postgreSQLParameters -> PostgreSQL Parameters).
-    """
-    ACRONYMS = {
-        # Database systems
-        "SQL": "SQL",
-        "MYSQL": "MySQL",
-        "POSTGRESQL": "PostgreSQL",
-        "MARIADB": "MariaDB",
-        "MSSQL": "MSSQL",
-        "MONGODB": "MongoDB",
-        "REDIS": "Redis",
-        # Protocols
-        "HTTP": "HTTP",
-        "HTTPS": "HTTPS",
-        "FTP": "FTP",
-        "SFTP": "SFTP",
-        "SSH": "SSH",
-        "TLS": "TLS",
-        "SSL": "SSL",
-        # APIs
-        "API": "API",
-        "REST": "REST",
-        "GRPC": "gRPC",
-        "GRAPHQL": "GraphQL",
-        # Networking
-        "URL": "URL",
-        "URI": "URI",
-        "FQDN": "FQDN",
-        "DNS": "DNS",
-        "IP": "IP",
-        "TCP": "TCP",
-        "UDP": "UDP",
-        # Data formats
-        "JSON": "JSON",
-        "XML": "XML",
-        "YAML": "YAML",
-        "CSV": "CSV",
-        "HTML": "HTML",
-        "CSS": "CSS",
-        # Hardware
-        "CPU": "CPU",
-        "RAM": "RAM",
-        "GPU": "GPU",
-        "SSD": "SSD",
-        "HDD": "HDD",
-        # Identifiers
-        "ID": "ID",
-        "UUID": "UUID",
-        "GUID": "GUID",
-        "ARN": "ARN",
-        # Cloud providers
-        "AWS": "AWS",
-        "GCP": "GCP",
-        "AZURE": "Azure",
-        "IBM": "IBM",
-        # Kubernetes/Cloud
-        "DB": "DB",
-        "PVC": "PVC",
-        "PV": "PV",
-        "VPN": "VPN",
-        # Auth
-        "OS": "OS",
-        "LDAP": "LDAP",
-        "SAML": "SAML",
-        "OAUTH": "OAuth",
-        "JWT": "JWT",
-        # AWS Services
-        "S3": "S3",
-        "EC2": "EC2",
-        "RDS": "RDS",
-        "EBS": "EBS",
-        "IAM": "IAM",
-    }
-
-    if "_" in title:
-        # Handle snake_case
-        title = title.replace("_", " ")
-        words = title.split()
-    else:
-        # Handle camelCase/PascalCase with smart splitting
-        # This regex splits on:
-        # - Transition from lowercase to uppercase (camelCase)
-        # - Transition from multiple uppercase to an uppercase followed by lowercase (SQLParameters -> SQL Parameters)
-        words = re.findall(r"[A-Z]+(?=[A-Z][a-z]|\b)|[A-Z][a-z]+|[a-z]+|[0-9]+", title)
-
-    # Merge adjacent words if they form a known compound acronym (e.g., postgre + SQL = PostgreSQL)
-    merged_words = []
-    i = 0
-    while i < len(words):
-        if i < len(words) - 1:
-            # Check if current word + next word form a known acronym
-            combined = (words[i] + words[i + 1]).upper()
-            if combined in ACRONYMS:
-                merged_words.append(combined)
-                i += 2
-                continue
-        merged_words.append(words[i])
-        i += 1
-
-    # Capitalize each word, using proper casing for known acronyms
-    result = []
-    for word in merged_words:
-        word_upper = word.upper()
-        if word_upper in ACRONYMS:
-            result.append(ACRONYMS[word_upper])
-        else:
-            result.append(word.capitalize())
-
-    return " ".join(result)
-
-
-def get_django_field(
-    field_schema, is_required, field_name, full_name, verbose_name_prefix=None
-):
-    field_type = field_schema.get("type") or "string"
-    format = field_schema.get("format")
-    verbose_name_prefix = verbose_name_prefix or ""
-    verbose_name = f"{verbose_name_prefix} {deslugify(field_name)}".strip()
-
-    # Pass down the requirement status from parent to child fields
-    kwargs = {
-        "blank": not is_required,  # All fields are optional by default
-        "null": not is_required,
-        "help_text": field_schema.get("description"),
-        "validators": [],
-        "verbose_name": verbose_name,
-        "default": field_schema.get("default"),
-    }
-
-    if minimum := field_schema.get("minimum"):
-        kwargs["validators"].append(MinValueValidator(minimum))
-    if maximum := field_schema.get("maximum"):
-        kwargs["validators"].append(MaxValueValidator(maximum))
-
-    if field_type == "string":
-        if format == "date-time":
-            return models.DateTimeField(**kwargs)
-        elif format == "date":
-            return models.DateField(**kwargs)
-        else:
-            max_length = field_schema.get("max_length") or 255
-            if pattern := field_schema.get("pattern"):
-                kwargs["validators"].append(RegexValidator(regex=pattern))
-            if choices := field_schema.get("enum"):
-                kwargs["choices"] = ((choice, choice) for choice in choices)
-            return models.CharField(max_length=max_length, **kwargs)
-    elif field_type == "integer":
-        return models.IntegerField(**kwargs)
-    elif field_type == "number":
-        return models.FloatField(**kwargs)
-    elif field_type == "boolean":
-        return models.BooleanField(**kwargs)
-    elif field_type == "object":
-        # Here we pass down the requirement status to nested objects
-        return build_object_fields(
-            field_schema,
-            full_name,
-            verbose_name_prefix=f"{verbose_name}:",
-            parent_required=is_required,
-        )
-    elif field_type == "array":
-        kwargs["help_text"] = field_schema.get("description") or _("List of values")
-        field = models.JSONField(**kwargs)
-        formfield_kwargs = {
-            "label": field.verbose_name,
-            "required": not field.blank,
-        }
-
-        array_validation = {}
-        if min_items := field_schema.get("min_items"):
-            array_validation["min_items"] = min_items
-        if max_items := field_schema.get("max_items"):
-            array_validation["max_items"] = max_items
-        if unique_items := field_schema.get("unique_items"):
-            array_validation["unique_items"] = unique_items
-        if items_schema := field_schema.get("items"):
-            array_validation["items_schema"] = items_schema
-        if array_validation:
-            formfield_kwargs["array_validation"] = array_validation
-
-        field.formfield = lambda: DynamicArrayField(**formfield_kwargs)
-
-        return field
-    return models.CharField(max_length=255, **kwargs)
-
-
-def unnest_data(data):
-    result = {}
-
-    def _flatten_dict(d, parent_key=""):
-        for key, value in d.items():
-            new_key = f"{parent_key}.{key}" if parent_key else key
-            if isinstance(value, dict):
-                _flatten_dict(value, new_key)
-            else:
-                result[new_key] = value
-
-    _flatten_dict(data)
-    return result
 
 
 class FormGeneratorMixin:
-    IS_CUSTOM_FORM = False
+    """Shared base class for ModelForm classes based on our generated CRD models.
+    There are two relevant child classes:
+        - CrdModelFormMixin: For fully auto-generated forms from the spec
+        - CustomFormMixin: For forms built from form_config settings.
+    """
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -570,6 +297,11 @@ class CustomFormMixin(FormGeneratorMixin):
                     )
                 elif field_type == "array":
                     field.widget = DynamicArrayWidget()
+                elif field_type == "choice":
+                    if hasattr(field, "choices") and field.choices:
+                        field._controlplane_choices = list(field.choices)
+                    if custom_choices := field_config.get("choices"):
+                        field.choices = [tuple(choice) for choice in custom_choices]
 
                 if field_type == "number":
                     min_val = field_config.get("min_value")
@@ -578,12 +310,17 @@ class CustomFormMixin(FormGeneratorMixin):
                     validators = []
                     if min_val is not None:
                         validators.append(MinValueValidator(min_val))
+                        field.widget.attrs["min"] = min_val
                     if max_val is not None:
                         validators.append(MaxValueValidator(max_val))
+                        field.widget.attrs["max"] = max_val
 
                     if validators:
                         field.validators.extend(validators)
 
+                if "default_value" in field_config and field.initial is None:
+                    field.initial = field_config["default_value"]
+
                 field.controlplane_field_mapping = field_name
 
     def get_fieldsets(self):
@@ -603,6 +340,25 @@ class CustomFormMixin(FormGeneratorMixin):
 
         return fieldsets
 
+    def clean(self):
+        cleaned_data = super().clean()
+
+        for field_name, field in self.fields.items():
+            if hasattr(field, "_controlplane_choices"):
+                value = cleaned_data.get(field_name)
+                if value:
+                    valid_values = [choice[0] for choice in field._controlplane_choices]
+                    if value not in valid_values:
+                        self.add_error(
+                            field_name,
+                            forms.ValidationError(
+                                f"'{value}' is not a valid choice. "
+                                f"Must be one of: {valid_values.join(', ')}"
+                            ),
+                        )
+
+        return cleaned_data
+
     def get_nested_data(self):
         nested = {}
         for field_name in self.fields.keys():

src/servala/core/crd/models.py

@@ -0,0 +1,167 @@
+from django.core.validators import MaxValueValidator, MinValueValidator, RegexValidator
+from django.db import models
+from django.utils.translation import gettext_lazy as _
+
+from servala.core.crd.utils import deslugify
+from servala.core.models import ServiceInstance
+from servala.frontend.forms.widgets import DynamicArrayField
+
+
+class CRDModel(models.Model):
+    """Base class for all virtual CRD models"""
+
+    def __init__(self, **kwargs):
+        if spec := kwargs.pop("spec", None):
+            kwargs.update(unnest_data({"spec": spec}))
+        super().__init__(**kwargs)
+
+    class Meta:
+        abstract = True
+
+
+def generate_django_model(schema, group, version, kind):
+    """
+    Generates a virtual Django model from a Kubernetes CRD's OpenAPI v3 schema.
+    """
+    # We always need these three fields to know our own name and our full namespace
+    model_fields = {"__module__": "crd_models"}
+    for field_name in ("name", "context"):
+        model_fields[field_name] = duplicate_field(field_name, ServiceInstance)
+
+    # All other fields are generated from the schema, except for the
+    # resourceRef object
+    spec = schema["properties"].get("spec") or {}
+    spec["properties"].pop("resourceRef", None)
+    model_fields.update(build_object_fields(spec, "spec", parent_required=False))
+
+    # Store the original schema on the model class
+    model_fields["SCHEMA"] = schema
+
+    meta_class = type("Meta", (), {"app_label": "crd_models"})
+    model_fields["Meta"] = meta_class
+
+    # create the model class
+    model_name = kind
+    model_class = type(model_name, (CRDModel,), model_fields)
+    return model_class
+
+
+def duplicate_field(field_name, model):
+    field = model._meta.get_field(field_name)
+    new_field = type(field).__new__(type(field))
+    new_field.__dict__.update(field.__dict__)
+    new_field.model = None
+    new_field.auto_created = False
+    return new_field
+
+
+def build_object_fields(schema, name, verbose_name_prefix=None, parent_required=False):
+    required_fields = schema.get("required") or []
+    properties = schema.get("properties") or {}
+    fields = {}
+
+    for field_name, field_schema in properties.items():
+        is_required = field_name in required_fields or parent_required
+        full_name = f"{name}.{field_name}"
+        result = get_django_field(
+            field_schema,
+            is_required,
+            field_name,
+            full_name,
+            verbose_name_prefix=verbose_name_prefix,
+        )
+        if isinstance(result, dict):
+            fields.update(result)
+        else:
+            fields[full_name] = result
+    return fields
+
+
+def get_django_field(
+    field_schema, is_required, field_name, full_name, verbose_name_prefix=None
+):
+    field_type = field_schema.get("type") or "string"
+    format = field_schema.get("format")
+    verbose_name_prefix = verbose_name_prefix or ""
+    verbose_name = f"{verbose_name_prefix} {deslugify(field_name)}".strip()
+
+    # Pass down the requirement status from parent to child fields
+    kwargs = {
+        "blank": not is_required,  # All fields are optional by default
+        "null": not is_required,
+        "help_text": field_schema.get("description"),
+        "validators": [],
+        "verbose_name": verbose_name,
+        "default": field_schema.get("default"),
+    }
+
+    if minimum := field_schema.get("minimum"):
+        kwargs["validators"].append(MinValueValidator(minimum))
+    if maximum := field_schema.get("maximum"):
+        kwargs["validators"].append(MaxValueValidator(maximum))
+
+    if field_type == "string":
+        if format == "date-time":
+            return models.DateTimeField(**kwargs)
+        elif format == "date":
+            return models.DateField(**kwargs)
+        else:
+            max_length = field_schema.get("max_length") or 255
+            if pattern := field_schema.get("pattern"):
+                kwargs["validators"].append(RegexValidator(regex=pattern))
+            if choices := field_schema.get("enum"):
+                kwargs["choices"] = ((choice, choice) for choice in choices)
+            return models.CharField(max_length=max_length, **kwargs)
+    elif field_type == "integer":
+        return models.IntegerField(**kwargs)
+    elif field_type == "number":
+        return models.FloatField(**kwargs)
+    elif field_type == "boolean":
+        return models.BooleanField(**kwargs)
+    elif field_type == "object":
+        # Here we pass down the requirement status to nested objects
+        return build_object_fields(
+            field_schema,
+            full_name,
+            verbose_name_prefix=f"{verbose_name}:",
+            parent_required=is_required,
+        )
+    elif field_type == "array":
+        kwargs["help_text"] = field_schema.get("description") or _("List of values")
+        field = models.JSONField(**kwargs)
+        formfield_kwargs = {
+            "label": field.verbose_name,
+            "required": not field.blank,
+        }
+
+        array_validation = {}
+        if min_items := field_schema.get("min_items"):
+            array_validation["min_items"] = min_items
+        if max_items := field_schema.get("max_items"):
+            array_validation["max_items"] = max_items
+        if unique_items := field_schema.get("unique_items"):
+            array_validation["unique_items"] = unique_items
+        if items_schema := field_schema.get("items"):
+            array_validation["items_schema"] = items_schema
+        if array_validation:
+            formfield_kwargs["array_validation"] = array_validation
+
+        field.formfield = lambda: DynamicArrayField(**formfield_kwargs)
+
+        return field
+    return models.CharField(max_length=255, **kwargs)
+
+
+def unnest_data(data):
+    result = {}
+
+    def _flatten_dict(d, parent_key=""):
+        for key, value in d.items():
+            new_key = f"{parent_key}.{key}" if parent_key else key
+            if isinstance(value, dict):
+                _flatten_dict(value, new_key)
+            else:
+                result[new_key] = value
+
+    _flatten_dict(data)
+    return result

src/servala/core/crd/utils.py

@@ -0,0 +1,115 @@
+import re
+
+
+def deslugify(title):
+    """
+    Convert camelCase, PascalCase, or snake_case to human-readable title.
+    Handles known acronyms (e.g., postgreSQLParameters -> PostgreSQL Parameters).
+    """
+    ACRONYMS = {
+        # Database systems
+        "SQL": "SQL",
+        "MYSQL": "MySQL",
+        "POSTGRESQL": "PostgreSQL",
+        "MARIADB": "MariaDB",
+        "MSSQL": "MSSQL",
+        "MONGODB": "MongoDB",
+        "REDIS": "Redis",
+        # Protocols
+        "HTTP": "HTTP",
+        "HTTPS": "HTTPS",
+        "FTP": "FTP",
+        "SFTP": "SFTP",
+        "SSH": "SSH",
+        "TLS": "TLS",
+        "SSL": "SSL",
+        # APIs
+        "API": "API",
+        "REST": "REST",
+        "GRPC": "gRPC",
+        "GRAPHQL": "GraphQL",
+        # Networking
+        "URL": "URL",
+        "URI": "URI",
+        "FQDN": "FQDN",
+        "DNS": "DNS",
+        "IP": "IP",
+        "TCP": "TCP",
+        "UDP": "UDP",
+        # Data formats
+        "JSON": "JSON",
+        "XML": "XML",
+        "YAML": "YAML",
+        "CSV": "CSV",
+        "HTML": "HTML",
+        "CSS": "CSS",
+        # Hardware
+        "CPU": "CPU",
+        "RAM": "RAM",
+        "GPU": "GPU",
+        "SSD": "SSD",
+        "HDD": "HDD",
+        # Identifiers
+        "ID": "ID",
+        "UUID": "UUID",
+        "GUID": "GUID",
+        "ARN": "ARN",
+        # Cloud providers
+        "AWS": "AWS",
+        "GCP": "GCP",
+        "AZURE": "Azure",
+        "IBM": "IBM",
+        # Kubernetes/Cloud
+        "DB": "DB",
+        "PVC": "PVC",
+        "PV": "PV",
+        "VPN": "VPN",
+        # Auth
+        "OS": "OS",
+        "LDAP": "LDAP",
+        "SAML": "SAML",
+        "OAUTH": "OAuth",
+        "JWT": "JWT",
+        # AWS Services
+        "S3": "S3",
+        "EC2": "EC2",
+        "RDS": "RDS",
+        "EBS": "EBS",
+        "IAM": "IAM",
+    }
+
+    if "_" in title:
+        # Handle snake_case
+        title = title.replace("_", " ")
+        words = title.split()
+    else:
+        # Handle camelCase/PascalCase with smart splitting
+        # This regex splits on:
+        # - Transition from lowercase to uppercase (camelCase)
+        # - Transition from multiple uppercase to an uppercase followed by lowercase (SQLParameters -> SQL Parameters)
+        words = re.findall(r"[A-Z]+(?=[A-Z][a-z]|\b)|[A-Z][a-z]+|[a-z]+|[0-9]+", title)
+
+    # Merge adjacent words if they form a known compound acronym (e.g., postgre + SQL = PostgreSQL)
+    merged_words = []
+    i = 0
+    while i < len(words):
+        if i < len(words) - 1:
+            # Check if current word + next word form a known acronym
+            combined = (words[i] + words[i + 1]).upper()
+            if combined in ACRONYMS:
+                merged_words.append(combined)
+                i += 2
+                continue
+        merged_words.append(words[i])
+        i += 1
+
+    # Capitalize each word, using proper casing for known acronyms
+    result = []
+    for word in merged_words:
+        word_upper = word.upper()
+        if word_upper in ACRONYMS:
+            result.append(ACRONYMS[word_upper])
+        else:
+            result.append(word.capitalize())
+
+    return " ".join(result)

src/servala/core/forms.py

@@ -218,6 +218,11 @@ class ServiceDefinitionAdminForm(forms.ModelForm):
                         )
                     )
 
+                if field.get("type") == "choice" and field.get("choices"):
+                    self._validate_choice_field(
+                        field, mapping, spec_schema, "spec", errors
+                    )
+
         if "name" not in included_mappings:
             raise forms.ValidationError(
                 {
@@ -230,6 +235,62 @@ class ServiceDefinitionAdminForm(forms.ModelForm):
         if errors:
             raise forms.ValidationError({"form_config": errors})
 
+    def _validate_choice_field(self, field, mapping, spec_schema, prefix, errors):
+        if not mapping:
+            return
+
+        field_schema = self._get_field_schema(spec_schema, mapping, prefix)
+        if not field_schema:
+            return
+
+        control_plane_choices = field_schema.get("enum", [])
+        if not control_plane_choices:
+            return
+
+        custom_choices = field.get("choices", [])
+        custom_choice_values = [choice[0] for choice in custom_choices]
+
+        invalid_choices = [
+            value
+            for value in custom_choice_values
+            if value not in control_plane_choices
+        ]
+
+        if invalid_choices:
+            field_name = field.get("label", mapping)
+            errors.append(
+                _(
+                    "Field '{}' has invalid choice values: {}. "
+                    "Valid choices from control plane are: {}"
+                ).format(
+                    field_name,
+                    ", ".join(f"'{c}'" for c in invalid_choices),
+                    ", ".join(f"'{c}'" for c in control_plane_choices),
+                )
+            )
+
+    def _get_field_schema(self, schema, field_path, prefix):
+        if not field_path or not schema:
+            return None
+
+        if field_path.startswith(prefix + "."):
+            field_path = field_path[len(prefix) + 1 :]
+
+        parts = field_path.split(".")
+        current_schema = schema
+
+        for part in parts:
+            if not isinstance(current_schema, dict):
+                return None
+
+            properties = current_schema.get("properties", {})
+            if part not in properties:
+                return None
+
+            current_schema = properties[part]
+
+        return current_schema
+
     def _extract_field_paths(self, schema, prefix=""):
         paths = set()
 

src/servala/core/migrations/0012_remove_advanced_fields.py

@@ -7,7 +7,7 @@ from django.db import migrations, models
 class Migration(migrations.Migration):
 
     dependencies = [
-        ("core", "0011_alter_organizationorigin_billing_entity"),
+        ("core", "0012_convert_user_info_to_array"),
     ]
 
     operations = [

src/servala/core/schemas/form_config_schema.json

@@ -48,21 +48,21 @@
                   "description": "Dot-notation path mapping to Kubernetes spec field (e.g., 'spec.parameters.service.fqdn')"
                 },
                 "max_length": {
-                  "type": "integer",
+                  "type": ["integer", "null"],
                   "description": "Maximum length for text/textarea fields",
                   "minimum": 1
                 },
                 "rows": {
-                  "type": "integer",
+                  "type": ["integer", "null"],
                   "description": "Number of rows for textarea fields",
                   "minimum": 1
                 },
                 "min_value": {
-                  "type": "number",
+                  "type": ["number", "null"],
                   "description": "Minimum value for number fields"
                 },
                 "max_value": {
-                  "type": "number",
+                  "type": ["number", "null"],
                   "description": "Maximum value for number fields"
                 },
                 "choices": {
@@ -76,12 +76,12 @@
                   }
                 },
                 "min_values": {
-                  "type": "integer",
+                  "type": ["integer", "null"],
                   "description": "Minimum number of values for array fields",
                   "minimum": 0
                 },
                 "max_values": {
-                  "type": "integer",
+                  "type": ["integer", "null"],
                   "description": "Maximum number of values for array fields",
                   "minimum": 1
                 },
@@ -92,6 +92,10 @@
                     "type": "string",
                     "enum": ["email", "fqdn", "url", "ipv4", "ipv6"]
                   }
+                },
+                "default_value": {
+                  "type": "string",
+                  "description": "Default value for the field when creating new instances"
                 }
               }
             }

src/servala/frontend/templates/includes/tabbed_fieldset_form.html

@@ -82,10 +82,11 @@
             </div>
         {% endif %}
     </div>
-    {% if form and expert_form %}
+    {% if expert_form %}
         <div id="expert-form-container"
              class="expert-crd-form"
-             style="display:none">
+             style="{% if form %}display:none{% endif %}">
+            {% if expert_form and expert_form.context %}{{ expert_form.context }}{% endif %}
             <ul class="nav nav-tabs" id="expertTab" role="tablist">
                 {% for fieldset in expert_form.get_fieldsets %}
                     {% if not fieldset.hidden %}
@@ -143,6 +144,7 @@
                value="{% if form_submit_label %}{{ form_submit_label }}{% else %}{% translate "Save" %}{% endif %}" />
     </div>
 </form>
+<script defer src="{% static 'js/bootstrap-tabs.js' %}"></script>
 {% if form %}
     <script defer src="{% static 'js/expert-mode.js' %}"></script>
 {% endif %}

src/servala/static/js/bootstrap-tabs.js

@@ -0,0 +1,30 @@
+// Bootstrap 5 automatically initializes tabs with data-bs-toggle="tab"
+// but we need to ensure they work after HTMX swaps
+(function() {
+    'use strict';
+
+    const initBootstrapTabs = () => {
+        const customTabList = document.querySelectorAll('#myTab button[data-bs-toggle="tab"]');
+        customTabList.forEach(function(tabButton) {
+            new bootstrap.Tab(tabButton);
+        });
+
+        const expertTabList = document.querySelectorAll('#expertTab button[data-bs-toggle="tab"]');
+        expertTabList.forEach(function(tabButton) {
+            new bootstrap.Tab(tabButton);
+        });
+    }
+
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', initBootstrapTabs);
+    } else {
+        initBootstrapTabs();
+    }
+
+    document.addEventListener('htmx:afterSwap', function(event) {
+        if (event.detail.target.id === 'service-form' ||
+            event.detail.target.classList.contains('crd-form')) {
+            initBootstrapTabs();
+        }
+    });
+})();

src/tests/test_form_config.py

@@ -0,0 +1,635 @@
+from unittest.mock import Mock
+
+import jsonschema
+from django.core.validators import MaxValueValidator, MinValueValidator
+from django.db import models
+
+from servala.core.crd import generate_custom_form_class
+from servala.core.forms import ServiceDefinitionAdminForm
+from servala.core.models import ControlPlaneCRD
+
+
+def test_custom_model_form_class_is_none_when_no_form_config():
+    crd = Mock(spec=ControlPlaneCRD)
+    service_def = Mock()
+    service_def.form_config = None
+    crd.service_definition = service_def
+    crd.django_model = Mock()
+
+    if not (
+        crd.django_model
+        and crd.service_definition
+        and crd.service_definition.form_config
+        and crd.service_definition.form_config.get("fieldsets")
+    ):
+        result = None
+    else:
+        result = generate_custom_form_class(
+            crd.service_definition.form_config, crd.django_model
+        )
+
+    assert result is None
+
+
+def test_custom_model_form_class_returns_class_when_form_config_exists():
+
+    crd = Mock(spec=ControlPlaneCRD)
+    service_def = Mock()
+    service_def.form_config = {
+        "fieldsets": [
+            {
+                "title": "General",
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "required": True,
+                    }
+                ],
+            }
+        ]
+    }
+    crd.service_definition = service_def
+
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+
+        class Meta:
+            app_label = "test"
+
+    crd.django_model = TestModel
+
+    if not (
+        crd.django_model
+        and crd.service_definition
+        and crd.service_definition.form_config
+        and crd.service_definition.form_config.get("fieldsets")
+    ):
+        result = None
+    else:
+        result = generate_custom_form_class(
+            crd.service_definition.form_config, crd.django_model
+        )
+
+    assert result is not None
+    assert hasattr(result, "form_config")
+
+
+def test_form_config_schema_validates_minimal_config():
+    form = ServiceDefinitionAdminForm()
+    schema = form.form_config_schema
+
+    minimal_config = {
+        "fieldsets": [
+            {
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Service Name",
+                        "controlplane_field_mapping": "spec.serviceName",
+                    }
+                ]
+            }
+        ]
+    }
+
+    jsonschema.validate(instance=minimal_config, schema=schema)
+
+
+def test_form_config_schema_validates_config_with_null_integers():
+    form = ServiceDefinitionAdminForm()
+    schema = form.form_config_schema
+
+    config_with_nulls = {
+        "fieldsets": [
+            {
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Service Name",
+                        "controlplane_field_mapping": "spec.serviceName",
+                        "max_length": None,
+                        "required": False,
+                    },
+                    {
+                        "type": "textarea",
+                        "label": "Description",
+                        "controlplane_field_mapping": "spec.description",
+                        "rows": None,
+                        "max_length": None,
+                    },
+                    {
+                        "type": "number",
+                        "label": "Port",
+                        "controlplane_field_mapping": "spec.port",
+                        "min_value": None,
+                        "max_value": None,
+                    },
+                    {
+                        "type": "array",
+                        "label": "Tags",
+                        "controlplane_field_mapping": "spec.tags",
+                        "min_values": None,
+                        "max_values": None,
+                    },
+                ]
+            }
+        ]
+    }
+
+    jsonschema.validate(instance=config_with_nulls, schema=schema)
+
+
+def test_form_config_schema_validates_full_config():
+    form = ServiceDefinitionAdminForm()
+    schema = form.form_config_schema
+
+    full_config = {
+        "fieldsets": [
+            {
+                "title": "Service Configuration",
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Service Name",
+                        "controlplane_field_mapping": "spec.serviceName",
+                        "help_text": "Enter a unique service name",
+                        "required": True,
+                        "max_length": 100,
+                    },
+                    {
+                        "type": "email",
+                        "label": "Admin Email",
+                        "controlplane_field_mapping": "spec.adminEmail",
+                        "help_text": "Contact email for service administrator",
+                        "required": True,
+                        "max_length": 255,
+                    },
+                    {
+                        "type": "textarea",
+                        "label": "Description",
+                        "controlplane_field_mapping": "spec.description",
+                        "help_text": "Describe the service purpose",
+                        "required": False,
+                        "rows": 5,
+                        "max_length": 500,
+                    },
+                    {
+                        "type": "number",
+                        "label": "Port",
+                        "controlplane_field_mapping": "spec.port",
+                        "help_text": "Service port number",
+                        "required": True,
+                        "min_value": 1,
+                        "max_value": 65535,
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "spec.environment",
+                        "help_text": "Deployment environment",
+                        "required": True,
+                        "choices": [
+                            ["dev", "Development"],
+                            ["staging", "Staging"],
+                            ["prod", "Production"],
+                        ],
+                    },
+                    {
+                        "type": "checkbox",
+                        "label": "Enable Monitoring",
+                        "controlplane_field_mapping": "spec.monitoring.enabled",
+                        "help_text": "Enable service monitoring",
+                        "required": False,
+                    },
+                    {
+                        "type": "array",
+                        "label": "Tags",
+                        "controlplane_field_mapping": "spec.tags",
+                        "help_text": "Service tags for organization",
+                        "required": False,
+                        "min_values": 0,
+                        "max_values": 10,
+                    },
+                ],
+            }
+        ]
+    }
+    jsonschema.validate(instance=full_config, schema=schema)
+
+
+def test_choice_field_uses_custom_choices_from_form_config():
+    """Test that choice fields use custom choices when provided in form_config"""
+
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+        environment = models.CharField(
+            max_length=20,
+            choices=[
+                ("dev", "Development"),
+                ("staging", "Staging"),
+                ("prod", "Production"),
+                ("test", "Testing"),
+            ],
+        )
+
+        class Meta:
+            app_label = "test"
+
+    form_config = {
+        "fieldsets": [
+            {
+                "title": "General",
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "required": True,
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "environment",
+                        "required": True,
+                        "choices": [["dev", "Development"], ["prod", "Production"]],
+                    },
+                ],
+            }
+        ]
+    }
+
+    form_class = generate_custom_form_class(form_config, TestModel)
+    form = form_class()
+
+    environment_field = form.fields["environment"]
+    assert list(environment_field.choices) == [
+        ("dev", "Development"),
+        ("prod", "Production"),
+    ]
+
+    assert hasattr(environment_field, "_controlplane_choices")
+    assert len(environment_field._controlplane_choices) == 5  # 4 choices + empty choice
+
+
+def test_choice_field_uses_control_plane_choices_when_no_custom_choices():
+
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+        environment = models.CharField(
+            max_length=20,
+            choices=[
+                ("dev", "Development"),
+                ("staging", "Staging"),
+                ("prod", "Production"),
+            ],
+        )
+
+        class Meta:
+            app_label = "test"
+
+    form_config = {
+        "fieldsets": [
+            {
+                "title": "General",
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "required": True,
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "environment",
+                        "required": True,
+                    },
+                ],
+            }
+        ]
+    }
+
+    form_class = generate_custom_form_class(form_config, TestModel)
+    form = form_class()
+
+    environment_field = form.fields["environment"]
+    choices_list = list(environment_field.choices)
+    assert len(choices_list) == 4  # 3 choices + empty choice
+    assert ("dev", "Development") in choices_list
+
+
+def test_choice_field_validates_against_control_plane_choices():
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+        environment = models.CharField(
+            max_length=20,
+            choices=[
+                ("dev", "Development"),
+                ("staging", "Staging"),
+                ("prod", "Production"),
+            ],
+        )
+
+        class Meta:
+            app_label = "test"
+
+    form_config = {
+        "fieldsets": [
+            {
+                "title": "General",
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "required": True,
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "environment",
+                        "required": True,
+                        "choices": [["dev", "Development"], ["prod", "Production"]],
+                    },
+                ],
+            }
+        ]
+    }
+
+    form_class = generate_custom_form_class(form_config, TestModel)
+
+    form = form_class(data={"name": "test-service", "environment": "dev"})
+    form.fields["context"].required = False  # Skip context validation
+    assert form.is_valid(), f"Form should be valid but has errors: {form.errors}"
+
+    form = form_class(data={"name": "test-service", "environment": "prod"})
+    form.fields["context"].required = False  # Skip context validation
+    assert form.is_valid(), f"Form should be valid but has errors: {form.errors}"
+
+    form = form_class(data={"name": "test-service", "environment": "invalid"})
+    form.fields["context"].required = False  # Skip context validation
+    assert not form.is_valid()
+    assert "environment" in form.errors
+
+
+def test_admin_form_validates_choice_values_against_schema():
+
+    form = ServiceDefinitionAdminForm()
+    mock_crd = Mock()
+    mock_crd.resource_schema = {
+        "properties": {
+            "spec": {
+                "properties": {
+                    "environment": {
+                        "type": "string",
+                        "enum": ["dev", "staging", "prod"],
+                    }
+                }
+            }
+        }
+    }
+
+    valid_form_config = {
+        "fieldsets": [
+            {
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "spec.environment",
+                        "choices": [["dev", "Development"], ["prod", "Production"]],
+                    },
+                ]
+            }
+        ]
+    }
+
+    spec_schema = mock_crd.resource_schema["properties"]["spec"]
+    errors = []
+
+    for field in valid_form_config["fieldsets"][0]["fields"]:
+        if field.get("type") == "choice":
+            form._validate_choice_field(
+                field, field["controlplane_field_mapping"], spec_schema, "spec", errors
+            )
+
+    assert len(errors) == 0, f"Expected no errors but got: {errors}"
+
+    invalid_form_config = {
+        "fieldsets": [
+            {
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "spec.environment",
+                        "choices": [
+                            ["dev", "Development"],
+                            ["invalid", "Invalid Environment"],
+                        ],
+                    },
+                ]
+            }
+        ]
+    }
+
+    errors = []
+
+    for field in invalid_form_config["fieldsets"][0]["fields"]:
+        if field.get("type") == "choice":
+            form._validate_choice_field(
+                field, field["controlplane_field_mapping"], spec_schema, "spec", errors
+            )
+
+    assert len(errors) > 0, "Expected validation errors but got none"
+    error_message = str(errors[0])
+    assert "invalid" in error_message.lower()
+    assert "Environment" in error_message
+
+
+def test_number_field_min_max_sets_widget_attributes():
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+        port = models.IntegerField()
+        replica_count = models.IntegerField()
+
+        class Meta:
+            app_label = "test"
+
+    form_config = {
+        "fieldsets": [
+            {
+                "title": "General",
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "required": True,
+                    },
+                    {
+                        "type": "number",
+                        "label": "Port",
+                        "controlplane_field_mapping": "port",
+                        "required": True,
+                        "min_value": 1,
+                        "max_value": 65535,
+                    },
+                    {
+                        "type": "number",
+                        "label": "Replicas",
+                        "controlplane_field_mapping": "replica_count",
+                        "required": True,
+                        "min_value": 1,
+                        "max_value": 10,
+                    },
+                ],
+            }
+        ]
+    }
+
+    form_class = generate_custom_form_class(form_config, TestModel)
+    form = form_class()
+
+    port_field = form.fields["port"]
+    assert port_field.widget.attrs.get("min") == 1
+    assert port_field.widget.attrs.get("max") == 65535
+
+    replica_field = form.fields["replica_count"]
+    assert replica_field.widget.attrs.get("min") == 1
+    assert replica_field.widget.attrs.get("max") == 10
+
+    port_validators = port_field.validators
+    assert any(
+        isinstance(v, MinValueValidator) and v.limit_value == 1 for v in port_validators
+    )
+    assert any(
+        isinstance(v, MaxValueValidator) and v.limit_value == 65535
+        for v in port_validators
+    )
+
+
+def test_default_value_for_all_field_types():
+
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+        description = models.TextField()
+        port = models.IntegerField()
+        environment = models.CharField(
+            max_length=20,
+            choices=[
+                ("dev", "Development"),
+                ("staging", "Staging"),
+                ("prod", "Production"),
+            ],
+        )
+        monitoring_enabled = models.BooleanField()
+        tags = models.JSONField()
+
+        class Meta:
+            app_label = "test"
+
+    form_config = {
+        "fieldsets": [
+            {
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "default_value": "default-name",
+                    },
+                    {
+                        "type": "textarea",
+                        "label": "Description",
+                        "controlplane_field_mapping": "description",
+                        "default_value": "Default description text",
+                    },
+                    {
+                        "type": "number",
+                        "label": "Port",
+                        "controlplane_field_mapping": "port",
+                        "default_value": "8080",
+                    },
+                    {
+                        "type": "choice",
+                        "label": "Environment",
+                        "controlplane_field_mapping": "environment",
+                        "default_value": "dev",
+                    },
+                    {
+                        "type": "checkbox",
+                        "label": "Enable Monitoring",
+                        "controlplane_field_mapping": "monitoring_enabled",
+                        "default_value": "true",
+                    },
+                    {
+                        "type": "array",
+                        "label": "Tags",
+                        "controlplane_field_mapping": "tags",
+                        "default_value": "tag1,tag2,tag3",
+                    },
+                ],
+            }
+        ]
+    }
+
+    form_class = generate_custom_form_class(form_config, TestModel)
+    form = form_class()
+
+    assert form.fields["name"].initial == "default-name"
+    assert form.fields["description"].initial == "Default description text"
+    assert form.fields["port"].initial == "8080"
+    assert form.fields["environment"].initial == "dev"
+    assert form.fields["monitoring_enabled"].initial == "true"
+    assert form.fields["tags"].initial == "tag1,tag2,tag3"
+
+
+def test_default_value_not_override_existing_instance():
+
+    class TestModel(models.Model):
+        name = models.CharField(max_length=100)
+        port = models.IntegerField()
+
+        class Meta:
+            app_label = "test"
+
+    form_config = {
+        "fieldsets": [
+            {
+                "fields": [
+                    {
+                        "type": "text",
+                        "label": "Name",
+                        "controlplane_field_mapping": "name",
+                        "default_value": "default-name",
+                    },
+                    {
+                        "type": "number",
+                        "label": "Port",
+                        "controlplane_field_mapping": "port",
+                        "default_value": "8080",
+                    },
+                ],
+            }
+        ]
+    }
+
+    instance = TestModel(name="existing-name", port=3000)
+    form_class = generate_custom_form_class(form_config, TestModel)
+    form = form_class(instance=instance)
+
+    assert form.initial["name"] == "existing-name"
+    assert form.initial["port"] == 3000