[sdk-vpp#314] Add label chain elements and condition

.golangci.yml

@@ -285,3 +285,6 @@ issues:
     - path: pkg/networkservice/common/switchcase/.*_test.go
       linters:
         - dupl
+    - path: pkg/networkservice/common/label/.*_test.go
+      linters:
+        - dupl

pkg/networkservice/common/label/client.go

@@ -0,0 +1,50 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package label
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+	"google.golang.org/protobuf/types/known/emptypb"
+
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+)
+
+type labelClient struct {
+	label, value string
+}
+
+// NewClient returns new server marking Connections with label
+func NewClient(label, value string) networkservice.NetworkServiceClient {
+	return &labelClient{
+		label: label,
+		value: value,
+	}
+}
+
+func (s *labelClient) Request(ctx context.Context, request *networkservice.NetworkServiceRequest, opts ...grpc.CallOption) (*networkservice.Connection, error) {
+	store(ctx, s.label, s.value)
+	return next.Client(ctx).Request(ctx, request, opts...)
+}
+
+func (s *labelClient) Close(ctx context.Context, conn *networkservice.Connection, opts ...grpc.CallOption) (*emptypb.Empty, error) {
+	store(ctx, s.label, s.value)
+	return next.Client(ctx).Close(ctx, conn, opts...)
+}

pkg/networkservice/common/label/client_test.go

@@ -0,0 +1,90 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package label_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/label"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/null"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/switchcase"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/updatepath"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/adapters"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/checks/checkcontext"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
+)
+
+func TestLabelClient(t *testing.T) {
+	const labelKey = "key"
+	const labelValue = "value"
+
+	c := next.NewNetworkServiceClient(
+		updatepath.NewClient("name"),
+		metadata.NewClient(),
+		label.NewClient(labelKey, labelValue),
+		switchcase.NewClient(
+			&switchcase.ClientCase{
+				Condition: label.Condition(labelKey, "invalid"),
+				Client: checkcontext.NewClient(t, func(t *testing.T, _ context.Context) {
+					require.Fail(t, "invalid label selected for client branch")
+				}),
+			},
+			&switchcase.ClientCase{
+				Condition: label.Condition(labelKey, labelValue),
+				Client:    null.NewClient(),
+			},
+			&switchcase.ClientCase{
+				Condition: switchcase.Default,
+				Client: checkcontext.NewClient(t, func(t *testing.T, _ context.Context) {
+					require.Fail(t, "no label selected for client branch")
+				}),
+			},
+		),
+		adapters.NewServerToClient(
+			switchcase.NewServer(
+				&switchcase.ServerCase{
+					Condition: label.Condition(labelKey, "invalid"),
+					Server: checkcontext.NewServer(t, func(t *testing.T, _ context.Context) {
+						require.Fail(t, "invalid label selected for server branch")
+					}),
+				},
+				&switchcase.ServerCase{
+					Condition: label.Condition(labelKey, labelValue),
+					Server:    null.NewServer(),
+				},
+				&switchcase.ServerCase{
+					Condition: switchcase.Default,
+					Server: checkcontext.NewServer(t, func(t *testing.T, _ context.Context) {
+						require.Fail(t, "no label selected for server branch")
+					}),
+				},
+			),
+		),
+	)
+
+	_, err := c.Request(context.Background(), new(networkservice.NetworkServiceRequest))
+	require.NoError(t, err)
+
+	_, err = c.Close(context.Background(), new(networkservice.Connection))
+	require.NoError(t, err)
+}

pkg/networkservice/common/label/condition.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package label
+
+import (
+	"context"
+
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/common/switchcase"
+)
+
+// Condition returns condition validating if Connection is marked with label
+func Condition(label, value string) switchcase.Condition {
+	return func(ctx context.Context, _ *networkservice.Connection) bool {
+		return load(ctx, label) == value
+	}
+}

pkg/networkservice/common/label/doc.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package label provides chain elements for marking Connection with label and switchcase.Condition for selecting branch
+// by label
+package label

pkg/networkservice/common/label/gen.go

@@ -0,0 +1,25 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package label
+
+import (
+	"sync"
+)
+
+//go:generate go-syncmap -output string_map.gen.go -type stringMap<string,string>
+
+type stringMap sync.Map

pkg/networkservice/common/label/metadata.go

@@ -0,0 +1,41 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package label
+
+import (
+	"context"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
+)
+
+type keyType struct{}
+
+func store(ctx context.Context, label, value string) {
+	v, _ := metadata.Map(ctx, false).LoadOrStore(keyType{}, new(stringMap))
+	labels := v.(*stringMap)
+
+	labels.Store(label, value)
+}
+
+func load(ctx context.Context, label string) string {
+	v, _ := metadata.Map(ctx, false).LoadOrStore(keyType{}, new(stringMap))
+	labels := v.(*stringMap)
+
+	value, _ := labels.Load(label)
+
+	return value
+}

pkg/networkservice/common/label/server.go

@@ -0,0 +1,49 @@
+// Copyright (c) 2021 Doc.ai and/or its affiliates.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at:
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package label
+
+import (
+	"context"
+
+	"google.golang.org/protobuf/types/known/emptypb"
+
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+)
+
+type labelServer struct {
+	label, value string
+}
+
+// NewServer returns new server marking Connections with label
+func NewServer(label, value string) networkservice.NetworkServiceServer {
+	return &labelServer{
+		label: label,
+		value: value,
+	}
+}
+
+func (s *labelServer) Request(ctx context.Context, request *networkservice.NetworkServiceRequest) (*networkservice.Connection, error) {
+	store(ctx, s.label, s.value)
+	return next.Server(ctx).Request(ctx, request)
+}
+
+func (s *labelServer) Close(ctx context.Context, conn *networkservice.Connection) (*emptypb.Empty, error) {
+	store(ctx, s.label, s.value)
+	return next.Server(ctx).Close(ctx, conn)
+}