Add tracing defaults for jaeger (#934)

* Add tracing defaults for jaeger

* Fix tests

* Add comment in config file as well

config.dev.toml

@@ -119,15 +119,17 @@ GithubToken = ""
 # Env override: ATHENS_HGRC_PATH
 HGRCPath = ""
 
-# TraceExporterURL is the URL to which Athens populates distributed tracing
-# information such as Jaeger. In Stackdriver, use this as the GCP ProjectID.
-# Env override: ATHENS_TRACE_EXPORTER_URL
-TraceExporterURL = ""
-
+# Tracing is not a requirement for Athens. If the infrastructure is not set up,
+# Athens will keep on running and traces won't be exported.
 # TraceExporter is the service to which the data collected by OpenCensus can be exported to.
 # Possible values are: jaeger, datadog, and stackdriver.
 # Env overide: ATHENS_TRACE_EXPORTER
-TraceExporter = ""
+TraceExporter = "jaeger"
+
+# TraceExporterURL is the URL to which Athens populates distributed tracing
+# information such as Jaeger. In Stackdriver, use this as the GCP ProjectID.
+# Env override: ATHENS_TRACE_EXPORTER_URL
+TraceExporterURL = "http://localhost:14268"
 
 [Storage]
     # Only storage backends that are specified in Proxy.StorageType are required here

pkg/config/config_test.go

@@ -208,12 +208,14 @@ func TestParseExampleConfig(t *testing.T) {
 		TimeoutConf: TimeoutConf{
 			Timeout: 300,
 		},
-		StorageType:    "memory",
-		GlobalEndpoint: "http://localhost:3001",
-		Port:           ":3000",
-		BasicAuthUser:  "",
-		BasicAuthPass:  "",
-		Storage:        expStorage,
+		StorageType:      "memory",
+		GlobalEndpoint:   "http://localhost:3001",
+		Port:             ":3000",
+		BasicAuthUser:    "",
+		BasicAuthPass:    "",
+		Storage:          expStorage,
+		TraceExporterURL: "http://localhost:14268",
+		TraceExporter:    "jaeger",
 	}
 
 	absPath, err := filepath.Abs(exampleConfigPath)
@@ -240,7 +242,6 @@ func getEnvMap(config *Config) map[string]string {
 		"BUFFALO_LOG_LEVEL":       config.BuffaloLogLevel,
 		"ATHENS_CLOUD_RUNTIME":    config.CloudRuntime,
 		"ATHENS_TIMEOUT":          strconv.Itoa(config.Timeout),
-		"ATHENS_TRACE_EXPORTER":   config.TraceExporterURL,
 	}
 
 	envVars["ATHENS_STORAGE_TYPE"] = config.StorageType