Chore: Init auth model on server side (#95142)

* Chore: Init auth model on server side

* fix linter

pkg/services/authz/zanzana.go

@@ -56,7 +56,10 @@ func ProvideZanzana(cfg *setting.Cfg, db db.DB, features featuremgmt.FeatureTogg
 			return nil, fmt.Errorf("failed to start zanzana: %w", err)
 		}
 
-		srv := zanzana.NewAuthzServer(openfga)
+		srv, err := zanzana.NewAuthzServer(cfg, openfga)
+		if err != nil {
+			return nil, fmt.Errorf("failed to start zanzana: %w", err)
+		}
 		channel := &inprocgrpc.Channel{}
 		openfgav1.RegisterOpenFGAServiceServer(channel, openfga)
 		authzv1.RegisterAuthzServiceServer(channel, srv)
@@ -114,7 +117,10 @@ func (z *Zanzana) start(ctx context.Context) error {
 		return fmt.Errorf("failed to start zanzana: %w", err)
 	}
 
-	srv := zanzana.NewAuthzServer(openfga)
+	srv, err := zanzana.NewAuthzServer(z.cfg, openfga)
+	if err != nil {
+		return fmt.Errorf("failed to start zanzana: %w", err)
+	}
 
 	tracingCfg, err := tracing.ProvideTracingConfig(z.cfg)
 	if err != nil {

pkg/services/authz/zanzana/server.go

@@ -1,6 +1,8 @@
 package zanzana
 
 import (
+	"fmt"
+
 	openfgav1 "github.com/openfga/api/proto/openfga/v1"
 	"github.com/openfga/openfga/pkg/server"
 	"github.com/openfga/openfga/pkg/storage"
@@ -16,8 +18,16 @@ func NewOpenFGAServer(cfg *setting.Cfg, store storage.OpenFGADatastore, logger l
 	return zserver.NewOpenFGA(&cfg.Zanzana, store, logger)
 }
 
-func NewAuthzServer(openfga openfgav1.OpenFGAServiceServer) *zserver.Server {
-	return zserver.NewAuthz(openfga)
+func NewAuthzServer(cfg *setting.Cfg, openfga openfgav1.OpenFGAServiceServer) (*zserver.Server, error) {
+	stackID := cfg.StackID
+	if stackID == "" {
+		stackID = "default"
+	}
+
+	return zserver.NewAuthz(
+		openfga,
+		zserver.WithTenantID(fmt.Sprintf("stack-%s", stackID)),
+	)
 }
 
 func StartOpenFGAHttpSever(cfg *setting.Cfg, srv grpcserver.Provider, logger log.Logger) error {

pkg/services/authz/zanzana/server/authz_server.go

@@ -2,12 +2,18 @@ package server
 
 import (
 	"context"
+	"errors"
+	"fmt"
 
 	authzv1 "github.com/grafana/authlib/authz/proto/v1"
 	openfgav1 "github.com/openfga/api/proto/openfga/v1"
+	"github.com/openfga/language/pkg/go/transformer"
 	"go.opentelemetry.io/otel"
+	"google.golang.org/protobuf/types/known/wrapperspb"
 
+	"github.com/grafana/grafana/pkg/infra/log"
 	authzextv1 "github.com/grafana/grafana/pkg/services/authz/zanzana/proto/v1"
+	"github.com/grafana/grafana/pkg/services/authz/zanzana/schema"
 )
 
 var _ authzv1.AuthzServiceServer = (*Server)(nil)
@@ -15,18 +21,179 @@ var _ authzextv1.AuthzExtentionServiceServer = (*Server)(nil)
 
 var tracer = otel.Tracer("github.com/grafana/grafana/pkg/services/authz/zanzana/server")
 
-func NewAuthz(openfga openfgav1.OpenFGAServiceServer) *Server {
-	return &Server{openfga: openfga}
-}
+var errStoreNotFound = errors.New("store not found")
 
 type Server struct {
 	authzv1.UnimplementedAuthzServiceServer
 	authzextv1.UnimplementedAuthzExtentionServiceServer
 
 	openfga openfgav1.OpenFGAServiceServer
+
+	logger   log.Logger
+	modules  []transformer.ModuleFile
+	tenantID string
+	storeID  string
+	modelID  string
+}
+
+type ServerOption func(s *Server)
+
+func WithTenantID(tenantID string) ServerOption {
+	return func(s *Server) {
+		s.tenantID = tenantID
+	}
+}
+
+func WithLogger(logger log.Logger) ServerOption {
+	return func(s *Server) {
+		s.logger = logger
+	}
+}
+
+func WithSchema(modules []transformer.ModuleFile) ServerOption {
+	return func(s *Server) {
+		s.modules = modules
+	}
+}
+
+func NewAuthz(openfga openfgav1.OpenFGAServiceServer, opts ...ServerOption) (*Server, error) {
+	s := &Server{openfga: openfga}
+
+	for _, o := range opts {
+		o(s)
+	}
+
+	if s.logger == nil {
+		s.logger = log.New("authz-server")
+	}
+
+	if s.tenantID == "" {
+		s.tenantID = "stack-default"
+	}
+
+	if len(s.modules) == 0 {
+		s.modules = schema.SchemaModules
+	}
+
+	ctx := context.Background()
+	store, err := s.getOrCreateStore(ctx, s.tenantID)
+	if err != nil {
+		return nil, err
+	}
+
+	s.storeID = store.GetId()
+
+	modelID, err := s.loadModel(ctx, s.storeID, s.modules)
+	if err != nil {
+		return nil, err
+	}
+
+	s.modelID = modelID
+
+	return s, nil
 }
 
 func (s *Server) Check(ctx context.Context, r *authzv1.CheckRequest) (*authzv1.CheckResponse, error) {
 	tracer.Start(ctx, "authzServer.Check")
+
 	return &authzv1.CheckResponse{}, nil
 }
+
+func (s *Server) getOrCreateStore(ctx context.Context, name string) (*openfgav1.Store, error) {
+	store, err := s.getStore(ctx, name)
+
+	if errors.Is(err, errStoreNotFound) {
+		var res *openfgav1.CreateStoreResponse
+		res, err = s.openfga.CreateStore(ctx, &openfgav1.CreateStoreRequest{Name: name})
+		if res != nil {
+			store = &openfgav1.Store{
+				Id:        res.GetId(),
+				Name:      res.GetName(),
+				CreatedAt: res.GetCreatedAt(),
+			}
+		}
+	}
+
+	return store, err
+}
+
+func (s *Server) getStore(ctx context.Context, name string) (*openfgav1.Store, error) {
+	var continuationToken string
+
+	// OpenFGA client does not support any filters for stores.
+	// We should create an issue to support some way to get stores by name.
+	// For now we need to go thourh all stores until we find a match or we hit the end.
+	for {
+		res, err := s.openfga.ListStores(ctx, &openfgav1.ListStoresRequest{
+			PageSize:          &wrapperspb.Int32Value{Value: 20},
+			ContinuationToken: continuationToken,
+		})
+
+		if err != nil {
+			return nil, fmt.Errorf("failed to initiate zanzana tenant: %w", err)
+		}
+
+		for _, s := range res.GetStores() {
+			if s.GetName() == name {
+				return s, nil
+			}
+		}
+
+		// we have no more stores to check
+		if res.GetContinuationToken() == "" {
+			return nil, errStoreNotFound
+		}
+
+		continuationToken = res.GetContinuationToken()
+	}
+}
+
+func (s *Server) loadModel(ctx context.Context, storeID string, modules []transformer.ModuleFile) (string, error) {
+	var continuationToken string
+
+	model, err := schema.TransformModulesToModel(modules)
+	if err != nil {
+		return "", err
+	}
+
+	for {
+		// ReadAuthorizationModels returns authorization models for a store sorted in descending order of creation.
+		// So with a pageSize of 1 we will get the latest model.
+		res, err := s.openfga.ReadAuthorizationModels(ctx, &openfgav1.ReadAuthorizationModelsRequest{
+			StoreId:           storeID,
+			PageSize:          &wrapperspb.Int32Value{Value: 20},
+			ContinuationToken: continuationToken,
+		})
+
+		if err != nil {
+			return "", fmt.Errorf("failed to load authorization model: %w", err)
+		}
+
+		for _, m := range res.GetAuthorizationModels() {
+			// If provided dsl is equal to a stored dsl we use that as the authorization id
+			if schema.EqualModels(m, model) {
+				return m.GetId(), nil
+			}
+		}
+
+		// If we have not found any matching authorization model we break the loop and create a new one
+		if res.GetContinuationToken() == "" {
+			break
+		}
+
+		continuationToken = res.GetContinuationToken()
+	}
+
+	writeRes, err := s.openfga.WriteAuthorizationModel(ctx, &openfgav1.WriteAuthorizationModelRequest{
+		StoreId:         s.storeID,
+		TypeDefinitions: model.GetTypeDefinitions(),
+		SchemaVersion:   model.GetSchemaVersion(),
+		Conditions:      model.GetConditions(),
+	})
+
+	if err != nil {
+		return "", fmt.Errorf("failed to load authorization model: %w", err)
+	}
+
+	return writeRes.GetAuthorizationModelId(), nil
+}