Add config support with jsonschema validation

Signed-off-by: Per Goncalves da Silva <pegoncal@redhat.com>

Author: Per Goncalves da Silva

internal/operator-controller/rukpak/bundle/config.go

@@ -0,0 +1,201 @@
+package bundle
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/invopop/jsonschema"
+	schemavalidation "github.com/santhosh-tekuri/jsonschema/v6"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/util/validation"
+
+	"github.com/operator-framework/api/pkg/operators/v1alpha1"
+)
+
+const (
+	dns1123SubdomainFormat = "RFC-1123"
+)
+
+var unsupportedInstallModes = sets.New[v1alpha1.InstallModeType](v1alpha1.InstallModeTypeMultiNamespace)
+
+// dnsFormat checks conformity to RFC1213 lowercase dns subdomain format by any field with format 'RFC-1123'
+var dnsFormat = &schemavalidation.Format{
+	Name: dns1123SubdomainFormat,
+	Validate: func(v any) error {
+		if v == nil {
+			return nil
+		}
+		s, ok := v.(string)
+		if !ok {
+			return fmt.Errorf("invalid type %T, expected string", v)
+		}
+		errs := validation.IsDNS1123Subdomain(s)
+		if len(errs) > 0 {
+			return errors.New(strings.Join(errs, ", "))
+		}
+		return nil
+	},
+}
+
+// Config is a registry+v1 bundle configuration surface
+type Config struct {
+	// WatchNamespace is supported for certain bundles to allow the user to configure installation in Single- or OwnNamespace modes
+	// The validation behavior of this field is determined by the install modes supported by the bundle, e.g.:
+	// - If a bundle only supports AllNamespaces mode (or only OwnNamespace mode): this field will be unknown
+	// - If a bundle supports AllNamespaces and SingleNamespace install modes: this field is optional
+	// - If a bundle supports AllNamespaces and OwnNamespace: this field is optional, but if set must be equal to the install namespace
+	WatchNamespace string `json:"watchNamespace,omitempty"`
+}
+
+// ValidatedBundleConfigFromRaw returns a validated Config struct from the values given in rawConfig.
+// The applied validation will be determined by the install modes supported by the bundle
+func ValidatedBundleConfigFromRaw(rv1 RegistryV1, installNamespace string, rawConfig map[string]interface{}) (*Config, error) {
+	if len(rawConfig) == 0 {
+		return nil, nil
+	}
+
+	rawSchema := bundleConfigSchema(rv1, installNamespace)
+	if err := validateBundleConfig(rawSchema, rawConfig); err != nil {
+		return nil, fmt.Errorf("invalid configuration: %v", err)
+	}
+
+	return toConfig(rawConfig)
+}
+
+// bundleConfigSchema generates a jsonschema used to validate bundle configuration
+func bundleConfigSchema(rv1 RegistryV1, installNamespace string) []byte {
+	// configure reflector
+	r := new(jsonschema.Reflector)
+	r.ExpandedStruct = true
+	r.AllowAdditionalProperties = false
+
+	// generate base schema
+	schema := r.Reflect(&Config{})
+
+	// apply bundle rawConfig based mutations for watchNamespace
+	configureWatchNamespaceProperty(rv1, installNamespace, schema)
+
+	// return schema
+	out, err := schema.MarshalJSON()
+	if err != nil {
+		panic(err)
+	}
+	return out
+}
+
+// configureWatchNamespaceProperty modifies schema to configure the watchNamespace config property based on
+// the install modes supported by the bundle marking the field required or optional, or restricting the possible values
+// it can take
+func configureWatchNamespaceProperty(rv1 RegistryV1, installNamespace string, schema *jsonschema.Schema) {
+	supportedInstallModes := sets.New[v1alpha1.InstallModeType]()
+	for _, im := range rv1.CSV.Spec.InstallModes {
+		if im.Supported && !unsupportedInstallModes.Has(im.Type) {
+			supportedInstallModes.Insert(im.Type)
+		}
+	}
+
+	allSupported := supportedInstallModes.Has(v1alpha1.InstallModeTypeAllNamespaces)
+	singleSupported := supportedInstallModes.Has(v1alpha1.InstallModeTypeSingleNamespace)
+	ownSupported := supportedInstallModes.Has(v1alpha1.InstallModeTypeOwnNamespace)
+
+	if len(supportedInstallModes) == 0 {
+		panic("bundle does not support any supported install modes")
+	}
+
+	// no watchNamespace rawConfig parameter if bundle only supports AllNamespaces or OwnNamespace install modes
+	if len(supportedInstallModes) == 1 && (allSupported || ownSupported) {
+		schema.Properties.Delete("watchNamespace")
+		return
+	}
+
+	watchNamespaceProperty, ok := schema.Properties.Get("watchNamespace")
+	if !ok {
+		panic("watchNamespace not found in schema")
+	}
+
+	watchNamespaceProperty.Format = dns1123SubdomainFormat
+
+	// required or optional
+	if !allSupported && singleSupported {
+		schema.Required = append(schema.Required, "watchNamespace")
+	} else {
+		// note: the library currently doesn't support jsonschema.Types
+		// this is the current workaround for declaring optional/nullable fields
+		// https://github.com/invopop/jsonschema/issues/115
+		watchNamespaceProperty.Extras = map[string]any{
+			"type": []string{"string", "null"},
+		}
+	}
+
+	// must be the install namespace
+	if allSupported && ownSupported && !singleSupported {
+		watchNamespaceProperty.Enum = []any{
+			installNamespace,
+			nil,
+		}
+	}
+}
+
+// validateBundleConfig validates the bundle rawConfig
+func validateBundleConfig(rawSchema []byte, rawConfig map[string]interface{}) error {
+	schema, err := schemavalidation.UnmarshalJSON(strings.NewReader(string(rawSchema)))
+	if err != nil {
+		return err
+	}
+
+	compiler := schemavalidation.NewCompiler()
+	compiler.RegisterFormat(dnsFormat)
+	compiler.AssertFormat()
+	if err := compiler.AddResource("schema.json", schema); err != nil {
+		return err
+	}
+	compiledSchema, err := compiler.Compile("schema.json")
+	if err != nil {
+		return err
+	}
+
+	return formatJSONSchemaValidationError(compiledSchema.Validate(rawConfig))
+}
+
+// toConfig converts rawConfig into a Config struct
+func toConfig(rawConfig map[string]interface{}) (*Config, error) {
+	cfg := Config{}
+	dataBytes, err := json.Marshal(rawConfig)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(dataBytes, &cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return &cfg, nil
+}
+
+// formatJSONSchemaValidationError extracts and formats the jsonschema validation errors given by the underlying library
+func formatJSONSchemaValidationError(err error) error {
+	var validationErr *schemavalidation.ValidationError
+	if !errors.As(err, &validationErr) {
+		return err
+	}
+	var errs []error
+	for _, cause := range validationErr.Causes {
+		if cause == nil || cause.BasicOutput() == nil {
+			continue
+		}
+
+		output := cause.BasicOutput()
+		instanceLocation := strings.ReplaceAll(output.InstanceLocation, "/", ".")
+		if instanceLocation == "" {
+			errs = append(errs, fmt.Errorf("%v", output.Error))
+		} else {
+			errs = append(errs, fmt.Errorf("at path %q: %s", instanceLocation, output.Error))
+		}
+	}
+	if len(errs) > 0 {
+		return errors.Join(errs...)
+	}
+	return err
+}