Add reva-gateway endpoint to service discovery

Reva can't be wrapped as a go-micro service due to private apis. We workaround byy manually registering the address and port in the service-registry.

pkg/service/external/external.go

@@ -0,0 +1,66 @@
+package external
+
+import (
+	"context"
+	"time"
+
+	"github.com/micro/go-micro/broker"
+	"github.com/micro/go-micro/v2/registry"
+	"github.com/owncloud/ocis-pkg/v2/log"
+)
+
+// RegisterGRPCEndpoint publishes an arbitrary endpoint to the service-registry. This allows to query nodes of
+// non-micro GRPC-services like reva. No health-checks are done, thus the caller is responsible for canceling.
+//
+func RegisterGRPCEndpoint(ctx context.Context, serviceID string, uuid string, addr string, logger log.Logger) error {
+	node := &registry.Node{
+		Id:       serviceID + "-" + uuid,
+		Address:  addr,
+		Metadata: make(map[string]string),
+	}
+	node.Metadata["broker"] = broker.String()
+	node.Metadata["registry"] = registry.String()
+	node.Metadata["server"] = "grpc"
+	node.Metadata["transport"] = "grpc"
+	node.Metadata["protocol"] = "grpc"
+
+	service := &registry.Service{
+		Name:      serviceID,
+		Version:   "",
+		Nodes:     []*registry.Node{node},
+		Endpoints: make([]*registry.Endpoint, 0),
+	}
+
+	rOpts := []registry.RegisterOption{registry.RegisterTTL(time.Minute)}
+
+	logger.Info().Msgf("Registering external service %v@%v", node.Id, node.Address)
+
+	if err := registry.Register(service, rOpts...); err != nil {
+		logger.Fatal().Err(err).Msgf("Registration error for external service %v", serviceID)
+	}
+
+	t := time.NewTicker(time.Second * 30)
+
+	go func() {
+		for {
+			select {
+			case <-t.C:
+				logger.Debug().Interface("service", service).Msg("Refreshing external service-registration")
+				err := registry.Register(service, rOpts...)
+				if err != nil {
+					logger.Error().Err(err).Msgf("Registration error for external service %v", serviceID)
+				}
+			case <-ctx.Done():
+				logger.Debug().Interface("service", service).Msg("Unregistering")
+				t.Stop()
+				err := registry.Deregister(service)
+				if err != nil {
+					logger.Err(err).Msgf("Error unregistering external service %v", serviceID)
+				}
+
+			}
+		}
+	}()
+
+	return nil
+}

pkg/service/external/external_test.go

@@ -0,0 +1,56 @@
+package external
+
+import (
+	"context"
+	"testing"
+
+	"github.com/micro/go-micro/v2/registry"
+	"github.com/owncloud/ocis-pkg/v2/log"
+)
+
+func TestRegisterGRPCEndpoint(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	err := RegisterGRPCEndpoint(ctx, "test", "1234", "192.168.0.1:777", log.Logger{})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	s, err := registry.GetService("test")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	if len(s) != 1 {
+		t.Errorf("Expected exactly one service to be returned got %v", len(s))
+	}
+
+	if len(s[0].Nodes) != 1 {
+		t.Errorf("Expected exactly one node to be returned got %v", len(s[0].Nodes))
+	}
+
+	testSvc := s[0]
+	if testSvc.Name != "test" {
+		t.Errorf("Expected service name to be 'test' got %v", s[0].Name)
+	}
+
+	testNode := testSvc.Nodes[0]
+
+	if testNode.Address != "192.168.0.1:777" {
+		t.Errorf("Expected node address to be '192.168.0.1:777' got %v", testNode.Address)
+	}
+
+	if testNode.Id != "test-1234" {
+		t.Errorf("Expected node id to be 'test-1234' got %v", testNode.Id)
+	}
+
+	cancel()
+
+	s, err = registry.GetService("test")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	if len(s) != 0 {
+		t.Errorf("Deregister on cancelation failed. Result-length should be zero, got %v", len(s))
+	}
+}