feat: add a composite service to provide fallback mechanisms

1 files changed, 34 insertions, 0 deletions

diff --git a/pkg/authz/composite_check_service.go b/pkg/authz/composite_check_service.go
new file mode 100644
index 0000000..5dfdfa8
--- /dev/null
+++ b/pkg/authz/composite_check_service.go
@@ -0,0 +1,34 @@
+package authz
+
+import (
+	"context"
+	"errors"
+
+	auth "github.com/envoyproxy/go-control-plane/envoy/service/auth/v3"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/pkg/pls"
+)
+
+type CompositeCheckService struct {
+	services []auth.AuthorizationServer
+	auth.UnimplementedAuthorizationServer
+}
+
+func NewCheckService(services []auth.AuthorizationServer) auth.AuthorizationServer {
+	return &CompositeCheckService{
+		services: services,
+	}
+}
+
+func (svc *CompositeCheckService) Check(ctx context.Context, request *auth.CheckRequest) (*auth.CheckResponse, error) {
+	for _, client := range svc.services {
+		response, err := client.Check(ctx, request)
+		if err != nil {
+			pls.LogError(ctx, err)
+			continue
+		}
+
+		return response, err
+	}
+
+	return nil, errors.New("Unable to perform check")
+}