config.yaml: categorize and reorganize YAML file

Categorize namespaces of each item into: - exporters - interceptors - zpages which aesthetically looks nicer than the original but also gives users better context and control over what the agent does. For example here is the new configuration file: ```yaml interceptors: opencensus: address: "127.0.0.1:55678" exporters: stackdriver: project: "project-id" enable_tracing: true zipkin: endpoint: "http://localhost:9411/api/v2/spans" datadog: enable_tracing: false zpages: port: 55679 ``` Fixes census-instrumentation#90
RenaultAI · Oct 18, 2018 · d243c31 · d243c31
1 parent 3cd221b
commit d243c31
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Showing 6 changed files with 106 additions and 54 deletions.
diff --git a/README.md b/README.md
@@ -261,12 +261,13 @@ it with the exporter and interceptor configurations.
 For example, to allow trace exporting to Stackdriver and Zipkin:
 
 ```yaml
-stackdriver:
-  project: "your-project-id"
-  enable_traces: true
+exporters:
+    stackdriver:
+        project: "your-project-id"
+        enable_traces: true
 
-zipkin:
-  endpoint: "http://localhost:9411/api/v2/spans"
+    zipkin:
+        endpoint: "http://localhost:9411/api/v2/spans"
 ```
 
 #### <a name="agent-config-interceptors"></a>Interceptors

diff --git a/cmd/ocagent/config.go b/cmd/ocagent/config.go
@@ -23,14 +23,36 @@ import (
 	"github.com/census-instrumentation/opencensus-service/exporter/exporterparser"
 )
 
+// We expect the configuration.yaml file to look like this:
+//
+//  interceptors:
+//      opencensus:
+//          port: <port>
+//      zipkin:
+//          reporter: <address>
+//
+//  exporters:
+//      stackdriver:
+//          project: <project_id>
+//          enable_tracing: true
+//      zipkin:
+//          endpoint: "http://localhost:9411/api/v2/spans"
+//
+//  zpages:
+//      port: 55679
+
 const (
 	defaultOCInterceptorAddress = "localhost:55678"
 	defaultZPagesPort           = 55679
 )
 
 type config struct {
-	OpenCensusInterceptorConfig *interceptorConfig `yaml:"opencensus_interceptor"`
-	ZPagesConfig                *zPagesConfig      `yaml:"zpages"`
+	Interceptors *interceptors `yaml:"interceptors"`
+	ZPages       *zPagesConfig `yaml:"zpages"`
+}
+
+type interceptors struct {
+	OpenCensusInterceptor *interceptorConfig `yaml:"opencensus"`
 }
 
 type interceptorConfig struct {
@@ -44,26 +66,30 @@ type zPagesConfig struct {
 }
 
 func (c *config) ocInterceptorAddress() string {
-	if c == nil || c.OpenCensusInterceptorConfig == nil || c.OpenCensusInterceptorConfig.Address == "" {
+	if c == nil || c.Interceptors == nil {
+		return defaultOCInterceptorAddress
+	}
+	inCfg := c.Interceptors
+	if inCfg.OpenCensusInterceptor == nil || inCfg.OpenCensusInterceptor.Address == "" {
 		return defaultOCInterceptorAddress
 	}
-	return c.OpenCensusInterceptorConfig.Address
+	return inCfg.OpenCensusInterceptor.Address
 }
 
 func (c *config) zPagesDisabled() bool {
 	if c == nil {
 		return true
 	}
-	return c.ZPagesConfig != nil && c.ZPagesConfig.Disabled
+	return c.ZPages != nil && c.ZPages.Disabled
 }
 
 func (c *config) zPagesPort() (int, bool) {
 	if c.zPagesDisabled() {
 		return -1, false
 	}
 	port := defaultZPagesPort
-	if c != nil && c.ZPagesConfig != nil && c.ZPagesConfig.Port > 0 {
-		port = c.ZPagesConfig.Port
+	if c != nil && c.ZPages != nil && c.ZPages.Port > 0 {
+		port = c.ZPages.Port
 	}
 	return port, true
 }
@@ -94,10 +120,19 @@ func exportersFromYAMLConfig(config []byte) (traceExporters []exporter.TraceExpo
 		if err != nil {
 			log.Fatalf("Failed to create config for %q: %v", cfg.name, err)
 		}
+		nonNilExporters := 0
 		for _, te := range tes {
 			if te != nil {
 				traceExporters = append(traceExporters, te)
+				nonNilExporters += 1
+			}
+		}
+		if nonNilExporters > 0 {
+			pluralization := "exporter"
+			if nonNilExporters > 1 {
+				pluralization = "exporters"
 			}
+			log.Printf("%q trace-%s enabled", cfg.name, pluralization)
 		}
 		for _, doneFn := range tesDoneFns {
 			doneFns = append(doneFns, doneFn)

diff --git a/cmd/ocagent/config.yaml b/cmd/ocagent/config.yaml
@@ -1,12 +1,14 @@
-opencensus_interceptor:
-  address: "127.0.0.1:55678"
+interceptors:
+    opencensus:
+        address: "127.0.0.1:55678"
 
-stackdriver:
-  project: "project-id"
-  enable_tracing: true
+exporters:
+    stackdriver:
+        project: "project-id"
+        enable_tracing: true
 
-zipkin:
-  endpoint: "http://localhost:9411/api/v2/spans"
+    zipkin:
+        endpoint: "http://localhost:9411/api/v2/spans"
 
 zpages:
-  port: 55679
+    port: 55679
diff --git a/exporter/exporterparser/datadog.go b/exporter/exporterparser/datadog.go
@@ -24,37 +24,42 @@ import (
 	"github.com/census-instrumentation/opencensus-service/exporter"
 )
 
-type dataDogConfig struct {
-	Datadog *struct {
-		// Namespace specifies the namespaces to which metric keys are appended.
-		Namespace string `yaml:"namespace,omitempty"`
+type datadogConfig struct {
+	// Namespace specifies the namespaces to which metric keys are appended.
+	Namespace string `yaml:"namespace,omitempty"`
 
-		// TraceAddr specifies the host[:port] address of the Datadog Trace Agent.
-		// It defaults to localhost:8126.
-		TraceAddr string `yaml:"trace_addr,omitempty"`
+	// TraceAddr specifies the host[:port] address of the Datadog Trace Agent.
+	// It defaults to localhost:8126.
+	TraceAddr string `yaml:"trace_addr,omitempty"`
 
-		// MetricsAddr specifies the host[:port] address for DogStatsD. It defaults
-		// to localhost:8125.
-		MetricsAddr string `yaml:"metrics_addr,omitempty"`
+	// MetricsAddr specifies the host[:port] address for DogStatsD. It defaults
+	// to localhost:8125.
+	MetricsAddr string `yaml:"metrics_addr,omitempty"`
 
-		// Tags specifies a set of global tags to attach to each metric.
-		Tags []string `yaml:"tags,omitempty"`
+	// Tags specifies a set of global tags to attach to each metric.
+	Tags []string `yaml:"tags,omitempty"`
 
-		EnableTracing bool `yaml:"enable_tracing,omitempty"`
-	} `yaml:"datadog,omitempty"`
+	EnableTracing bool `yaml:"enable_tracing,omitempty"`
 }
 
 type datadogExporter struct {
 	exporter *datadog.Exporter
 }
 
 func DatadogTraceExportersFromYAML(config []byte) (tes []exporter.TraceExporter, doneFns []func() error, err error) {
-	var c dataDogConfig
-	if err := yamlUnmarshal(config, &c); err != nil {
+	var cfg struct {
+		Exporters *struct {
+			Datadog *datadogConfig `yaml:"datadog"`
+		} `yaml:"exporters"`
+	}
+	if err := yamlUnmarshal(config, &cfg); err != nil {
 		return nil, nil, err
 	}
+	if cfg.Exporters == nil {
+		return nil, nil, nil
+	}
 
-	dc := c.Datadog
+	dc := cfg.Exporters.Datadog
 	if dc == nil {
 		return nil, nil, nil
 	}

diff --git a/exporter/exporterparser/stackdriver.go b/exporter/exporterparser/stackdriver.go
@@ -26,10 +26,8 @@ import (
 )
 
 type stackdriverConfig struct {
-	Stackdriver *struct {
-		ProjectID     string `yaml:"project,omitempty"`
-		EnableTracing bool   `yaml:"enable_tracing,omitempty"`
-	} `yaml:"stackdriver,omitempty"`
+	ProjectID     string `yaml:"project,omitempty"`
+	EnableTracing bool   `yaml:"enable_tracing,omitempty"`
 }
 
 type stackdriverExporter struct {
@@ -39,12 +37,18 @@ type stackdriverExporter struct {
 var _ exporter.TraceExporter = (*stackdriverExporter)(nil)
 
 func StackdriverTraceExportersFromYAML(config []byte) (tes []exporter.TraceExporter, doneFns []func() error, err error) {
-	var c stackdriverConfig
-	if err := yamlUnmarshal(config, &c); err != nil {
+	var cfg struct {
+		Exporters *struct {
+			Stackdriver *stackdriverConfig `yaml:"stackdriver"`
+		} `yaml:"exporters"`
+	}
+	if err := yamlUnmarshal(config, &cfg); err != nil {
 		return nil, nil, err
 	}
-
-	sc := c.Stackdriver
+	if cfg.Exporters == nil {
+		return nil, nil, nil
+	}
+	sc := cfg.Exporters.Stackdriver
 	if sc == nil {
 		return nil, nil, nil
 	}

diff --git a/exporter/exporterparser/zipkin.go b/exporter/exporterparser/zipkin.go
@@ -28,27 +28,32 @@ import (
 )
 
 type zipkinConfig struct {
-	Zipkin *struct {
-		ServiceName      string `yaml:"service_name,omitempty"`
-		Endpoint         string `yaml:"endpoint,omitempty"`
-		LocalEndpointURI string `yaml:"local_endpoint,omitempty"`
-	} `yaml:"zipkin,omitempty"`
+	ServiceName      string `yaml:"service_name,omitempty"`
+	Endpoint         string `yaml:"endpoint,omitempty"`
+	LocalEndpointURI string `yaml:"local_endpoint,omitempty"`
 }
 
 type zipkinExporter struct {
 	exporter *zipkin.Exporter
 }
 
 func ZipkinExportersFromYAML(config []byte) (tes []exporter.TraceExporter, doneFns []func() error, err error) {
-	var c zipkinConfig
-	if err := yamlUnmarshal(config, &c); err != nil {
+	var cfg struct {
+		Exporters *struct {
+			Zipkin *zipkinConfig `yaml:"zipkin"`
+		} `yaml:"exporters"`
+	}
+	if err := yamlUnmarshal(config, &cfg); err != nil {
 		return nil, nil, err
 	}
+	if cfg.Exporters == nil {
+		return nil, nil, nil
+	}
 
-	if c.Zipkin == nil {
+	zc := cfg.Exporters.Zipkin
+	if zc == nil {
 		return nil, nil, nil
 	}
-	zc := c.Zipkin
 	endpoint := "http://localhost:9411/api/v2/spans"
 	if zc.Endpoint != "" {
 		endpoint = zc.Endpoint