Delay data sources initialization, wire ingestion to init (#5091)

* Rego: Init Datasources Late

This commit initializes the data sources functions later in the rego evaluator
lifecycle, creating them after registering the built-in library.

Signed-off-by: Adolfo García Veytia (Puerco) <[email protected]>

* Wire ingestion results to DS init

Thist commit wires the ingestion results to the data source function
initialization to make it available in the DS func call.

Signed-off-by: Adolfo García Veytia (Puerco) <[email protected]>

---------

Signed-off-by: Adolfo García Veytia (Puerco) <[email protected]>

internal/engine/eval/rego/datasources.go

@@ -12,19 +12,35 @@ import (
 	"github.com/open-policy-agent/opa/types"
 
 	v1datasources "github.com/mindersec/minder/pkg/datasources/v1"
+	"github.com/mindersec/minder/pkg/engine/v1/interfaces"
 )
 
 // RegisterDataSources implements the Eval interface.
 func (e *Evaluator) RegisterDataSources(dsr *v1datasources.DataSourceRegistry) {
+	e.datasources = dsr
+}
+
+// buildDataSourceOptions creates an options set from the functions available in
+// a data source registry.
+func buildDataSourceOptions(res *interfaces.Result, dsr *v1datasources.DataSourceRegistry) []func(*rego.Rego) {
+	opts := []func(*rego.Rego){}
+	if dsr == nil {
+		return opts
+	}
+
 	for key, dsf := range dsr.GetFuncs() {
-		e.regoOpts = append(e.regoOpts, buildFromDataSource(key, dsf))
+		opts = append(opts, buildFromDataSource(res, key, dsf))
 	}
+
+	return opts
 }
 
 // buildFromDataSource builds a rego function from a data source function.
 // It takes a DataSourceFuncDef and returns a function that can be used to
 // register the function with the rego engine.
-func buildFromDataSource(key v1datasources.DataSourceFuncKey, dsf v1datasources.DataSourceFuncDef) func(*rego.Rego) {
+func buildFromDataSource(
+	_ *interfaces.Result, key v1datasources.DataSourceFuncKey, dsf v1datasources.DataSourceFuncDef,
+) func(*rego.Rego) {
 	k := normalizeKey(key)
 	return rego.Function1(
 		&rego.Function{

internal/engine/eval/rego/eval.go

@@ -15,6 +15,7 @@ import (
 
 	eoptions "github.com/mindersec/minder/internal/engine/options"
 	minderv1 "github.com/mindersec/minder/pkg/api/protobuf/go/minder/v1"
+	v1datasources "github.com/mindersec/minder/pkg/datasources/v1"
 	"github.com/mindersec/minder/pkg/engine/v1/interfaces"
 )
 
@@ -36,9 +37,10 @@ const (
 // It initializes the rego engine and evaluates the rules
 // The default rego package is "minder"
 type Evaluator struct {
-	cfg      *Config
-	regoOpts []func(*rego.Rego)
-	reseval  resultEvaluator
+	cfg         *Config
+	regoOpts    []func(*rego.Rego)
+	reseval     resultEvaluator
+	datasources *v1datasources.DataSourceRegistry
 }
 
 // Input is the input for the rego evaluator
@@ -113,10 +115,20 @@ func (e *Evaluator) Eval(
 	// this explicitly.
 	obj := res.Object
 
-	libFuncs := instantiateRegoLib(res)
+	// Register options to expose functions
+	regoFuncOptions := []func(*rego.Rego){}
+
+	// Initialize the built-in minder library rego functions
+	regoFuncOptions = append(regoFuncOptions, instantiateRegoLib(res)...)
+
+	// If the evaluator has data sources defined, expose their functions
+	regoFuncOptions = append(regoFuncOptions, buildDataSourceOptions(res, e.datasources)...)
+
+	// Create the rego object
 	r := e.newRegoFromOptions(
-		libFuncs...,
+		regoFuncOptions...,
 	)
+
 	pq, err := r.PrepareForEval(ctx)
 	if err != nil {
 		return fmt.Errorf("could not prepare Rego: %w", err)