Extract service.pipelines interface, add skeleton graph implementation (

#6764)

service/graph.go

@@ -0,0 +1,45 @@
+// Copyright The OpenTelemetry Authors
+//
+// 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 service // import "go.opentelemetry.io/collector/service"
+
+import (
+	"context"
+	"net/http"
+
+	"go.opentelemetry.io/collector/component"
+)
+
+var _ pipelines = (*pipelinesGraph)(nil)
+
+type pipelinesGraph struct{}
+
+func (g *pipelinesGraph) StartAll(ctx context.Context, host component.Host) error {
+	// TODO actual implementation
+	return nil
+}
+
+func (g *pipelinesGraph) ShutdownAll(ctx context.Context) error {
+	// TODO actual implementation
+	return nil
+}
+
+func (g *pipelinesGraph) GetExporters() map[component.DataType]map[component.ID]component.Component {
+	// TODO actual implementation
+	return make(map[component.DataType]map[component.ID]component.Component)
+}
+
+func (g *pipelinesGraph) HandleZPages(w http.ResponseWriter, r *http.Request) {
+	// TODO actual implementation
+}

service/host.go

@@ -36,7 +36,7 @@ type serviceHost struct {
 
 	buildInfo component.BuildInfo
 
-	pipelines         *builtPipelines
+	pipelines
 	serviceExtensions *extensions.Extensions
 }
 

service/pipelines.go

@@ -23,6 +23,7 @@ import (
 	"go.uber.org/multierr"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/connector"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/exporter"
 	"go.opentelemetry.io/collector/processor"
@@ -39,6 +40,15 @@ const (
 	zComponentKind = "zcomponentkind"
 )
 
+type pipelines interface {
+	StartAll(ctx context.Context, host component.Host) error
+	ShutdownAll(ctx context.Context) error
+	GetExporters() map[component.DataType]map[component.ID]component.Component
+	HandleZPages(w http.ResponseWriter, r *http.Request)
+}
+
+var _ pipelines = (*builtPipelines)(nil)
+
 // baseConsumer redeclared here since not public in consumer package. May consider to make that public.
 type baseConsumer interface {
 	Capabilities() consumer.Capabilities
@@ -187,13 +197,14 @@ type pipelinesSettings struct {
 	Receivers  *receiver.Builder
 	Processors *processor.Builder
 	Exporters  *exporter.Builder
+	Connectors *connector.Builder
 
 	// PipelineConfigs is a map of component.ID to PipelineConfig.
 	PipelineConfigs map[component.ID]*PipelineConfig
 }
 
 // buildPipelines builds all pipelines from config.
-func buildPipelines(ctx context.Context, set pipelinesSettings) (*builtPipelines, error) {
+func buildPipelines(ctx context.Context, set pipelinesSettings) (pipelines, error) {
 	exps := &builtPipelines{
 		telemetry:    set.Telemetry,
 		allReceivers: make(map[component.DataType]map[component.ID]component.Component),

service/pipelines_test.go

@@ -181,7 +181,7 @@ func TestBuildPipelines(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			// Build the pipeline
-			pipelines, err := buildPipelines(context.Background(), pipelinesSettings{
+			pips, err := buildPipelines(context.Background(), pipelinesSettings{
 				Telemetry: componenttest.NewNopTelemetrySettings(),
 				BuildInfo: component.NewDefaultBuildInfo(),
 				Receivers: receiver.NewBuilder(
@@ -211,7 +211,9 @@ func TestBuildPipelines(t *testing.T) {
 				PipelineConfigs: test.pipelineConfigs,
 			})
 			assert.NoError(t, err)
+			assert.IsType(t, &builtPipelines{}, pips)
 
+			pipelines := pips.(*builtPipelines)
 			assert.NoError(t, pipelines.StartAll(context.Background(), componenttest.NewNopHost()))
 
 			for dt, pipeline := range test.pipelineConfigs {