Use config for trace url (#681)

* Use config for trace url

* pr updates

* fix typo

* fix typo

cmd/proxy/actions/app.go

@@ -90,7 +90,7 @@ func App(conf *config.Config) (*buffalo.App, error) {
 	}
 
 	// Register exporter to export traces
-	exporter, err := observ.RegisterTraceExporter(Service, ENV)
+	exporter, err := observ.RegisterTraceExporter(conf.TraceExporterURL, Service, ENV)
 	if err != nil {
 		lggr.SystemErr(err)
 	} else {

config.example.toml

@@ -69,7 +69,6 @@ Timeout = 300
 # Env override: ATHENS_ENABLE_CSRF_PROTECTION
 EnableCSRFProtection = false
 
-
 [Proxy]
     # StorageType sets the type of storage backend the proxy will use.
     # Possible values are memory, disk, mongo, gcp, minio
@@ -128,6 +127,11 @@ EnableCSRFProtection = false
     # Env override: ATHENS_NETRC_PATH
     NETRCPath = ""
 
+    # TraceExporterURL is the URL to which Athens populates distributed tracing 
+    # information such as Jaeger. 
+    # Env override: ATHENS_TRACE_EXPORTER
+    TraceExporterURL = ""
+
 [Olympus]
     # StorageType sets the type of storage backend Olympus will use.
     # Possible values are memory, disk, mongo, postgres, sqlite, cockroach, mysql

pkg/config/env/trace.go

@@ -1,8 +0,0 @@
-package env
-
-import "os"
-
-// TraceExporterURL returns where the trace is stored to
-func TraceExporterURL() string {
-	return os.Getenv("TRACE_EXPORTER")
-}

pkg/config/parse.go

@@ -25,6 +25,7 @@ type Config struct {
 	CloudRuntime         string `validate:"required" envconfig:"ATHENS_CLOUD_RUNTIME"`
 	FilterFile           string `envconfig:"ATHENS_FILTER_FILE"`
 	EnableCSRFProtection bool   `envconfig:"ATHENS_ENABLE_CSRF_PROTECTION"`
+	TraceExporterURL     string `envconfig:"ATHENS_TRACE_EXPORTER"`
 	Proxy                *ProxyConfig
 	Olympus              *OlympusConfig `validate:"-"` // ignoring validation until Olympus is up.
 	Storage              *StorageConfig

pkg/config/parse_test.go

@@ -351,6 +351,7 @@ func getEnvMap(config *Config) map[string]string {
 		"ATHENS_FILTER_FILE":            config.FilterFile,
 		"ATHENS_TIMEOUT":                strconv.Itoa(config.Timeout),
 		"ATHENS_ENABLE_CSRF_PROTECTION": strconv.FormatBool(config.EnableCSRFProtection),
+		"ATHENS_TRACE_EXPORTER":         config.TraceExporterURL,
 	}
 
 	proxy := config.Proxy

pkg/observ/tracing.go

@@ -5,7 +5,6 @@ import (
 	"net/http"
 
 	"github.com/gobuffalo/buffalo"
-	"github.com/gomods/athens/pkg/config/env"
 	"github.com/gomods/athens/pkg/errors"
 	"go.opencensus.io/exporter/jaeger"
 	"go.opencensus.io/trace"
@@ -20,15 +19,14 @@ type observabilityContext struct {
 // RegisterTraceExporter returns a jaeger exporter for exporting traces to opencensus.
 // It should in the future have a nice sampling rate defined
 // TODO: Extend beyond jaeger
-func RegisterTraceExporter(service, ENV string) (*(jaeger.Exporter), error) {
+func RegisterTraceExporter(URL, service, ENV string) (*(jaeger.Exporter), error) {
 	const op errors.Op = "RegisterTracer"
-	collectorEndpointURI := env.TraceExporterURL()
-	if collectorEndpointURI == "" {
+	if URL == "" {
 		return nil, errors.E(op, "Exporter URL is empty. Traces won't be exported")
 	}
 
 	je, err := jaeger.NewExporter(jaeger.Options{
-		Endpoint:    collectorEndpointURI,
+		Endpoint:    URL,
 		ServiceName: service,
 	})