feat(jaeger-v2): Create default config for all-in-one (#4842)

## Which problem is this PR solving?
In Jaeger V1 the all-in-one binary can be run without any arguments /
configuration, but since `jaeger-v2` is built on OTel Collector it
requires a config file. This is unnecessary friction for local /
development use of all-in-one.

## Description of the changes
- Allows all-in-one with memory storage to be run without any additional
config file
- Hardcodes a configuration in the code, relying on default
configuration from each component.

## How was this change tested?
- Ran locally
```
$ go run -tags=ui ./cmd/jaeger-v2
```

---------

Signed-off-by: Yuri Shkuro <github@ysh.us>

cmd/jaeger-v2/internal/all-in-one/.nocover

@@ -0,0 +1 @@
+FIXME

cmd/jaeger-v2/internal/all-in-one/config.go

@@ -0,0 +1,133 @@
+// Copyright (c) 2023 The Jaeger Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package allinone
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configtelemetry"
+	"go.opentelemetry.io/collector/otelcol"
+	"go.opentelemetry.io/collector/service"
+	"go.opentelemetry.io/collector/service/extensions"
+	"go.opentelemetry.io/collector/service/pipelines"
+	"go.opentelemetry.io/collector/service/telemetry"
+	"go.uber.org/zap/zapcore"
+
+	"github.com/jaegertracing/jaeger/cmd/jaeger-v2/internal/exporters/storageexporter"
+	"github.com/jaegertracing/jaeger/cmd/jaeger-v2/internal/extension/jaegerquery"
+	"github.com/jaegertracing/jaeger/cmd/jaeger-v2/internal/extension/jaegerstorage"
+)
+
+type configProvider struct {
+	watcher chan error
+}
+
+var _ otelcol.ConfigProvider = (*configProvider)(nil)
+
+// NewConfigProvider creates a new ConfigProvider.
+func NewConfigProvider() *configProvider {
+	return &configProvider{
+		watcher: make(chan error, 1),
+	}
+}
+
+func (cp *configProvider) Get(ctx context.Context, factories otelcol.Factories) (*otelcol.Config, error) {
+	cfg := &otelcol.Config{
+		Service:    cp.makeServiceConfig(),
+		Extensions: make(map[component.ID]component.Config),
+		Receivers:  make(map[component.ID]component.Config),
+		Processors: make(map[component.ID]component.Config),
+		Exporters:  make(map[component.ID]component.Config),
+	}
+	defaultConfigs("extension", cfg.Service.Extensions, cfg.Extensions, factories.Extensions)
+	for _, pipeCfg := range cfg.Service.Pipelines {
+		defaultConfigs("receiver", pipeCfg.Receivers, cfg.Receivers, factories.Receivers)
+		defaultConfigs("processor", pipeCfg.Processors, cfg.Processors, factories.Processors)
+		defaultConfigs("exporter", pipeCfg.Exporters, cfg.Exporters, factories.Exporters)
+	}
+	return cfg, nil
+}
+
+func defaultConfigs[TFactory component.Factory](
+	componentType string,
+	comps []component.ID,
+	outCfg map[component.ID]component.Config,
+	factories map[component.Type]TFactory,
+) error {
+	for _, compID := range comps {
+		f, ok := factories[compID.Type()]
+		if !ok {
+			return fmt.Errorf("no factory registered for %s %v", componentType, compID)
+		}
+		cfg := f.CreateDefaultConfig()
+		outCfg[compID] = cfg
+	}
+	return nil
+}
+
+// makeServiceConfig creates default config that contains
+// all standard all-in-one extensions and pipelines.
+func (cp *configProvider) makeServiceConfig() service.Config {
+	return service.Config{
+		Extensions: extensions.Config([]component.ID{
+			jaegerstorage.ID,
+			jaegerquery.ID,
+		}),
+		Pipelines: pipelines.Config(map[component.ID]*pipelines.PipelineConfig{
+			component.NewID("traces"): {
+				Receivers: []component.ID{
+					component.NewID("otlp"),
+					component.NewID("jaeger"),
+					component.NewID("zipkin"),
+				},
+				Processors: []component.ID{
+					component.NewID("batch"),
+				},
+				Exporters: []component.ID{
+					storageexporter.ID,
+				},
+			},
+		}),
+		// OTel Collector currently (v0.87) hardcodes telemetry settings, this is a copy.
+		// https://github.com/open-telemetry/opentelemetry-collector/blob/35512c466577036b0cc306673d2d4ad039c77f1c/otelcol/unmarshaler.go#L43
+		Telemetry: telemetry.Config{
+			Logs: telemetry.LogsConfig{
+				Level:       zapcore.InfoLevel,
+				Development: false,
+				Encoding:    "console",
+				Sampling: &telemetry.LogsSamplingConfig{
+					Enabled:    true,
+					Tick:       10 * time.Second,
+					Initial:    10,
+					Thereafter: 100,
+				},
+				OutputPaths:       []string{"stderr"},
+				ErrorOutputPaths:  []string{"stderr"},
+				DisableCaller:     false,
+				DisableStacktrace: false,
+				InitialFields:     map[string]any(nil),
+			},
+			Metrics: telemetry.MetricsConfig{
+				Level: configtelemetry.LevelNone,
+				// Address: ":8888",
+			},
+			// TODO initialize tracer
+		},
+	}
+}
+
+// Watch implements otelcol.ConfigProvider.
+// The returned channel is never written to, as there is no configuration to watch.
+func (cp *configProvider) Watch() <-chan error {
+	return cp.watcher
+}
+
+// Shutdown implements otelcol.ConfigProvider.
+func (cp *configProvider) Shutdown(ctx context.Context) error {
+	close(cp.watcher)
+	return nil
+}

cmd/jaeger-v2/internal/command.go

@@ -5,11 +5,13 @@ package internal
 
 import (
 	"log"
+	"strings"
 
 	"github.com/spf13/cobra"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/otelcol"
 
+	allinone "github.com/jaegertracing/jaeger/cmd/jaeger-v2/internal/all-in-one"
 	"github.com/jaegertracing/jaeger/pkg/version"
 )
 
@@ -21,20 +23,47 @@ func Command() *cobra.Command {
 		log.Fatalf("failed to build components: %v", err)
 	}
 
-	versionInfo := version.Get()
-
 	info := component.BuildInfo{
 		Command:     "jaeger-v2",
 		Description: description,
-		Version:     versionInfo.GitVersion,
+		Version:     version.Get().String(),
+	}
+
+	settings := otelcol.CollectorSettings{
+		BuildInfo: info,
+		Factories: factories,
 	}
 
-	cmd := otelcol.NewCommand(
-		otelcol.CollectorSettings{
-			BuildInfo: info,
-			Factories: factories,
-		},
-	)
+	cmd := otelcol.NewCommand(settings)
+
+	// We want to support running the binary in all-in-one mode without a config file.
+	// Since there are no explicit hooks in OTel Collector for that today (as of v0.87),
+	// we intercept the official RunE implementation and check if any --config flags are
+	// present in the args. If not, we pass a custom ConfigProvider, and create the
+	// collector manually. Unfortunately, `set`(ings) is passed to NewCommand above
+	// by value, otherwise we could've overwritten it in the interceptor and then delegated
+	// back to the official RunE.
+	otelRunE := cmd.RunE
+	cmd.RunE = func(cmd *cobra.Command, args []string) error {
+		configProvided := false
+		for _, arg := range args {
+			if strings.HasPrefix(arg, "--config") {
+				configProvided = true
+				break
+			}
+		}
+		if configProvided {
+			return otelRunE(cmd, args)
+		}
+		log.Print("No '--config' flags detected, using default All-in-One configuration with memory storage.")
+		log.Print("To customize All-in-One behavior, pass a proper configuration.")
+		settings.ConfigProvider = allinone.NewConfigProvider()
+		col, err := otelcol.NewCollector(settings)
+		if err != nil {
+			return err
+		}
+		return col.Run(cmd.Context())
+	}
 
 	cmd.Short = description
 	cmd.Long = description

cmd/jaeger-v2/internal/exporters/storageexporter/factory.go

@@ -10,11 +10,16 @@ import (
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/exporter"
 	"go.opentelemetry.io/collector/exporter/exporterhelper"
+
+	"github.com/jaegertracing/jaeger/cmd/jaeger-v2/internal/extension/jaegerstorage"
 )
 
 // componentType is the name of this extension in configuration.
 const componentType = component.Type("jaeger_storage_exporter")
 
+// ID is the identifier of this extension.
+var ID = component.NewID(componentType)
+
 // NewFactory creates a factory for jaeger_storage_exporter.
 func NewFactory() exporter.Factory {
 	return exporter.NewFactory(
@@ -25,7 +30,9 @@ func NewFactory() exporter.Factory {
 }
 
 func createDefaultConfig() component.Config {
-	return &Config{}
+	return &Config{
+		TraceStorage: jaegerstorage.DefaultMemoryStore,
+	}
 }
 
 func createTracesExporter(ctx context.Context, set exporter.CreateSettings, config component.Config) (exporter.Traces, error) {

cmd/jaeger-v2/internal/extension/jaegerquery/factory.go

@@ -10,18 +10,23 @@ import (
 	"go.opentelemetry.io/collector/config/confighttp"
 	"go.opentelemetry.io/collector/extension"
 
+	"github.com/jaegertracing/jaeger/cmd/jaeger-v2/internal/extension/jaegerstorage"
 	"github.com/jaegertracing/jaeger/ports"
 )
 
 // componentType is the name of this extension in configuration.
 const componentType = component.Type("jaeger_query")
 
+// ID is the identifier of this extension.
+var ID = component.NewID(componentType)
+
 func NewFactory() extension.Factory {
 	return extension.NewFactory(componentType, createDefaultConfig, createExtension, component.StabilityLevelBeta)
 }
 
 func createDefaultConfig() component.Config {
 	return &Config{
+		TraceStorage: jaegerstorage.DefaultMemoryStore,
 		HTTPServerSettings: confighttp.HTTPServerSettings{
 			Endpoint: ports.PortToHostPort(ports.QueryHTTP),
 		},

cmd/jaeger-v2/internal/extension/jaegerstorage/factory.go

@@ -8,10 +8,20 @@ import (
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/extension"
+
+	memoryCfg "github.com/jaegertracing/jaeger/pkg/memory/config"
+)
+
+const (
+	// componentType is the name of this extension in configuration.
+	componentType = component.Type("jaeger_storage")
+
+	// DefaultMemoryStore is the name of the memory storage included in the default configuration.
+	DefaultMemoryStore = "memstore"
 )
 
-// componentType is the name of this extension in configuration.
-const componentType = component.Type("jaeger_storage")
+// ID is the identifier of this extension.
+var ID = component.NewID(componentType)
 
 func NewFactory() extension.Factory {
 	return extension.NewFactory(
@@ -23,7 +33,13 @@ func NewFactory() extension.Factory {
 }
 
 func createDefaultConfig() component.Config {
-	return &Config{}
+	return &Config{
+		Memory: map[string]memoryCfg.Configuration{
+			DefaultMemoryStore: {
+				MaxTraces: 100_000,
+			},
+		},
+	}
 }
 
 // createExtension creates the extension based on this config.

pkg/version/build.go

@@ -69,7 +69,7 @@ func NewInfoMetrics(metricsFactory metrics.Factory) *InfoMetrics {
 
 func (i Info) String() string {
 	return fmt.Sprintf(
-		"application version: git-commit=%s, git-version=%s, build-date=%s",
+		"git-commit=%s, git-version=%s, build-date=%s",
 		i.GitCommit, i.GitVersion, i.BuildDate,
 	)
 }

pkg/version/command.go

@@ -25,7 +25,7 @@ import (
 // Command creates version command
 func Command() *cobra.Command {
 	info := Get()
-	log.Println(info)
+	log.Println("applicatio version:", info)
 	return &cobra.Command{
 		Use:   "version",
 		Short: "Print the version.",