Add entity properties to rego evaluation context.

This change adds the entity's properties as defined by the provider to
the REGO evaluation context, making it possible to use them as
arguments to e.g. data sources.

internal/engine/eval/rego/eval.go

@@ -12,6 +12,7 @@ import (
 	"github.com/open-policy-agent/opa/rego"
 	"github.com/open-policy-agent/opa/topdown/print"
 	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/types/known/structpb"
 
 	eoptions "github.com/mindersec/minder/internal/engine/options"
 	minderv1 "github.com/mindersec/minder/pkg/api/protobuf/go/minder/v1"
@@ -49,6 +50,9 @@ type Input struct {
 	Profile map[string]any `json:"profile"`
 	// Ingested is the values set for the ingested data
 	Ingested any `json:"ingested"`
+	// Properties contains the entity's properties as defined by
+	// the provider
+	Properties map[string]any `json:"properties"`
 	// OutputFormat is the format to output violations in
 	OutputFormat ConstraintsViolationsFormat `json:"output_format"`
 }
@@ -134,14 +138,31 @@ func (e *Evaluator) Eval(
 		return nil, fmt.Errorf("could not prepare Rego: %w", err)
 	}
 
-	rs, err := pq.Eval(ctx, rego.EvalInput(&Input{
+	input := &Input{
 		Profile:      pol,
 		Ingested:     obj,
 		OutputFormat: e.cfg.ViolationFormat,
-	}))
+	}
+
+	enrichInputWithEntityProps(input, entity)
+	rs, err := pq.Eval(ctx, rego.EvalInput(input))
 	if err != nil {
 		return nil, fmt.Errorf("error evaluating profile. Might be wrong input: %w", err)
 	}
 
 	return e.reseval.parseResult(rs, entity)
 }
+
+type propertiesFetcher interface {
+	GetProperties() *structpb.Struct
+}
+
+func enrichInputWithEntityProps(
+	input *Input,
+	entity protoreflect.ProtoMessage,
+) {
+	switch entity := entity.(type) {
+	case propertiesFetcher:
+		input.Properties = entity.GetProperties().AsMap()
+	}
+}