[jaeger-v2] Add support for artificial jaeger storage receiver (#5242)

## Which problem is this PR solving?
- Part of #4843
- Separate Jaeger storage receiver PR from and will be used by jaeger-v2
Kafka PR #4971

## Description of the changes
- Implement Jaeger storage receiver to be used by Jaeger-v2 Kafka
integration test.

## How was this change tested?
- Added some unit tests.

## Checklist
- [x] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [x] I have signed all commits
- [x] I have added unit tests for the new functionality
- [x] I have run lint and test steps successfully
  - for `jaeger`: `make lint test`
  - for `jaeger-ui`: `yarn lint` and `yarn test`

---------

Signed-off-by: James Ryans <james.ryans2012@gmail.com>

cmd/jaeger/integration/receivers/storagereceiver/README.md

@@ -0,0 +1,23 @@
+# Storage Receiver
+
+`storagereceiver` is a fake receiver that creates an artificial stream of traces by:
+
+- repeatedly querying one of Jaeger storage backends for all traces (by service).
+- tracking new traces / spans and passing them to the next component in the pipeline.
+
+# Getting Started
+
+The following settings are required:
+
+- `trace_storage` (no default): name of a storage backend defined in `jaegerstorage` extension
+
+The following settings can be optionally configured:
+
+- `pull_interval` (default = 0s): The delay between each iteration of pulling traces.
+
+```yaml
+receivers:
+  jaeger_storage_receiver:
+    trace_storage: external-storage
+    pull_interval: 0s
+```

cmd/jaeger/integration/receivers/storagereceiver/config.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storagereceiver
+
+import (
+	"time"
+
+	"github.com/asaskevich/govalidator"
+)
+
+type Config struct {
+	TraceStorage string        `valid:"required" mapstructure:"trace_storage"`
+	PullInterval time.Duration `mapstructure:"pull_interval"`
+}
+
+func (cfg *Config) Validate() error {
+	_, err := govalidator.ValidateStruct(cfg)
+	return err
+}

cmd/jaeger/integration/receivers/storagereceiver/config_test.go

@@ -0,0 +1,66 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storagereceiver
+
+import (
+	"errors"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/confmap/confmaptest"
+)
+
+func TestLoadConfig(t *testing.T) {
+	t.Parallel()
+
+	cm, err := confmaptest.LoadConf(filepath.Join("testdata", "config.yaml"))
+	require.NoError(t, err)
+
+	tests := []struct {
+		id          component.ID
+		expected    component.Config
+		expectedErr error
+	}{
+		{
+			id:          component.NewIDWithName(componentType, ""),
+			expectedErr: errors.New("non zero value required"),
+		},
+		{
+			id: component.NewIDWithName(componentType, "defaults"),
+			expected: &Config{
+				TraceStorage: "storage",
+				PullInterval: 0,
+			},
+		},
+		{
+			id: component.NewIDWithName(componentType, "filled"),
+			expected: &Config{
+				TraceStorage: "storage",
+				PullInterval: 2 * time.Second,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.id.String(), func(t *testing.T) {
+			factory := NewFactory()
+			cfg := factory.CreateDefaultConfig()
+
+			sub, err := cm.Sub(tt.id.String())
+			require.NoError(t, err)
+			require.NoError(t, component.UnmarshalConfig(sub, cfg))
+
+			if tt.expectedErr != nil {
+				require.ErrorContains(t, component.ValidateConfig(cfg), tt.expectedErr.Error())
+			} else {
+				require.NoError(t, component.ValidateConfig(cfg))
+				assert.Equal(t, tt.expected, cfg)
+			}
+		})
+	}
+}

cmd/jaeger/integration/receivers/storagereceiver/factory.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storagereceiver
+
+import (
+	"context"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/consumer"
+	"go.opentelemetry.io/collector/receiver"
+)
+
+// componentType is the name of this extension in configuration.
+const componentType = component.Type("jaeger_storage_receiver")
+
+func NewFactory() receiver.Factory {
+	return receiver.NewFactory(
+		componentType,
+		createDefaultConfig,
+		receiver.WithTraces(createTracesReceiver, component.StabilityLevelDevelopment),
+	)
+}
+
+func createDefaultConfig() component.Config {
+	return &Config{}
+}
+
+func createTracesReceiver(ctx context.Context, set receiver.CreateSettings, config component.Config, nextConsumer consumer.Traces) (receiver.Traces, error) {
+	cfg := config.(*Config)
+
+	return newTracesReceiver(cfg, set, nextConsumer)
+}

cmd/jaeger/integration/receivers/storagereceiver/factory_test.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storagereceiver
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/receiver/receivertest"
+)
+
+func TestCreateDefaultConfig(t *testing.T) {
+	cfg := createDefaultConfig().(*Config)
+	require.NotNil(t, cfg, "failed to create default config")
+	require.NoError(t, componenttest.CheckConfigStruct(cfg))
+}
+
+func TestCreateTracesReceiver(t *testing.T) {
+	cfg := createDefaultConfig().(*Config)
+	f := NewFactory()
+	r, err := f.CreateTracesReceiver(context.Background(), receivertest.NewNopCreateSettings(), cfg, nil)
+	require.NoError(t, err)
+	assert.NotNil(t, r)
+}

cmd/jaeger/integration/receivers/storagereceiver/package_test.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storagereceiver
+
+import (
+	"testing"
+
+	"github.com/jaegertracing/jaeger/pkg/testutils"
+)
+
+func TestMain(m *testing.M) {
+	testutils.VerifyGoLeaks(m)
+}

cmd/jaeger/integration/receivers/storagereceiver/receiver.go

@@ -0,0 +1,138 @@
+// Copyright (c) 2024 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package storagereceiver
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	jaeger2otlp "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/jaeger"
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/consumer"
+	"go.opentelemetry.io/collector/receiver"
+	"go.uber.org/zap"
+
+	"github.com/jaegertracing/jaeger/cmd/jaeger/internal/extension/jaegerstorage"
+	"github.com/jaegertracing/jaeger/model"
+	"github.com/jaegertracing/jaeger/storage/spanstore"
+)
+
+type storageReceiver struct {
+	cancelConsumeLoop context.CancelFunc
+	config            *Config
+	settings          receiver.CreateSettings
+	consumedTraces    map[model.TraceID]*consumedTrace
+	nextConsumer      consumer.Traces
+	spanReader        spanstore.Reader
+}
+
+type consumedTrace struct {
+	spanIDs map[model.SpanID]struct{}
+}
+
+func newTracesReceiver(config *Config, set receiver.CreateSettings, nextConsumer consumer.Traces) (*storageReceiver, error) {
+	return &storageReceiver{
+		config:         config,
+		settings:       set,
+		consumedTraces: make(map[model.TraceID]*consumedTrace),
+		nextConsumer:   nextConsumer,
+	}, nil
+}
+
+func (r *storageReceiver) Start(ctx context.Context, host component.Host) error {
+	f, err := jaegerstorage.GetStorageFactory(r.config.TraceStorage, host)
+	if err != nil {
+		return fmt.Errorf("cannot find storage factory: %w", err)
+	}
+
+	if r.spanReader, err = f.CreateSpanReader(); err != nil {
+		return fmt.Errorf("cannot create span reader: %w", err)
+	}
+
+	ctx, cancel := context.WithCancel(ctx)
+	r.cancelConsumeLoop = cancel
+
+	go func() {
+		if err := r.consumeLoop(ctx); err != nil {
+			r.settings.ReportStatus(component.NewFatalErrorEvent(err))
+		}
+	}()
+
+	return nil
+}
+
+func (r *storageReceiver) consumeLoop(ctx context.Context) error {
+	for {
+		services, err := r.spanReader.GetServices(ctx)
+		if err != nil {
+			r.settings.Logger.Error("Failed to get services from consumer", zap.Error(err))
+			return err
+		}
+
+		for _, svc := range services {
+			if err := r.consumeTraces(ctx, svc); err != nil {
+				r.settings.Logger.Error("Failed to consume traces from consumer", zap.Error(err))
+			}
+		}
+
+		select {
+		case <-ctx.Done():
+			r.settings.Logger.Info("Consumer stopped")
+			return nil
+		default:
+			time.Sleep(r.config.PullInterval)
+		}
+	}
+}
+
+func (r *storageReceiver) consumeTraces(ctx context.Context, serviceName string) error {
+	traces, err := r.spanReader.FindTraces(ctx, &spanstore.TraceQueryParameters{
+		ServiceName: serviceName,
+	})
+	if err != nil {
+		return err
+	}
+
+	for _, trace := range traces {
+		traceID := trace.Spans[0].TraceID
+		if _, ok := r.consumedTraces[traceID]; !ok {
+			r.consumedTraces[traceID] = &consumedTrace{
+				spanIDs: make(map[model.SpanID]struct{}),
+			}
+		}
+		r.consumeSpans(ctx, r.consumedTraces[traceID], trace.Spans)
+	}
+
+	return nil
+}
+
+func (r *storageReceiver) consumeSpans(ctx context.Context, tc *consumedTrace, spans []*model.Span) error {
+	// Spans are consumed one at a time because we don't know whether all spans
+	// in a trace have been completely exported
+	for _, span := range spans {
+		if _, ok := tc.spanIDs[span.SpanID]; !ok {
+			tc.spanIDs[span.SpanID] = struct{}{}
+			td, err := jaeger2otlp.ProtoToTraces([]*model.Batch{
+				{
+					Spans:   []*model.Span{span},
+					Process: span.Process,
+				},
+			})
+			if err != nil {
+				return err
+			}
+			r.nextConsumer.ConsumeTraces(ctx, td)
+		}
+	}
+
+	return nil
+}
+
+func (r *storageReceiver) Shutdown(_ context.Context) error {
+	if r.cancelConsumeLoop != nil {
+		r.cancelConsumeLoop()
+	}
+	return nil
+}