agent ignore statsdport

ddtrace/tracer/option.go

@@ -522,7 +522,7 @@ func newConfig(opts ...StartOption) *config {
 			// no config defined address; use defaults
 			addr = defaultDogstatsdAddr()
 		}
-		if agentport := c.agent.StatsdPort; agentport > 0 {
+		if agentport := c.agent.StatsdPort; agentport > 0 && !c.agent.ignore {
 			// the agent reported a non-standard port
 			host, _, err := net.SplitHostPort(addr)
 			if err == nil {
@@ -625,6 +625,10 @@ type agentFeatures struct {
 
 	// featureFlags specifies all the feature flags reported by the trace-agent.
 	featureFlags map[string]struct{}
+
+	// ignore indicates that we should ignore the agent in favor of user set values.
+	// It should only be used during testing.
+	ignore bool
 }
 
 // HasFlag reports whether the agent has set the feat feature flag.
@@ -653,16 +657,18 @@ func loadAgentFeatures(agentDisabled bool, agentURL *url.URL, httpClient *http.C
 	type infoResponse struct {
 		Endpoints     []string `json:"endpoints"`
 		ClientDropP0s bool     `json:"client_drop_p0s"`
-		StatsdPort    int      `json:"statsd_port"`
 		FeatureFlags  []string `json:"feature_flags"`
+		Config        struct {
+			StatsdPort int `json:"statsd_port"`
+		} `json:"config"`
 	}
 	var info infoResponse
 	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
 		log.Error("Decoding features: %v", err)
 		return
 	}
 	features.DropP0s = info.ClientDropP0s
-	features.StatsdPort = info.StatsdPort
+	features.StatsdPort = info.Config.StatsdPort
 	for _, endpoint := range info.Endpoints {
 		switch endpoint {
 		case "/v0.6/stats":
@@ -762,6 +768,12 @@ func WithFeatureFlags(feats ...string) StartOption {
 	}
 }
 
+func withIgnoreAgent(ignore bool) StartOption {
+	return func(c *config) {
+		c.agent.ignore = ignore
+	}
+}
+
 // WithLogger sets logger as the tracer's error printer.
 // Diagnostic and startup tracer logs are prefixed to simplify the search within logs.
 // If JSON logging format is required, it's possible to wrap tracer logs using an existing JSON logger with this

ddtrace/tracer/option_test.go

@@ -157,19 +157,19 @@ func TestAutoDetectStatsd(t *testing.T) {
 	t.Run("agent", func(t *testing.T) {
 		t.Run("default", func(t *testing.T) {
 			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-				w.Write([]byte(`{"statsd_port":0}`))
+				w.Write([]byte(`{"endpoints": [], "config": {"statsd_port":0}}`))
 			}))
 			defer srv.Close()
-			cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), WithAgentTimeout(2))
+			cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), WithAgentTimeout(2), withIgnoreAgent(true))
 			testStatsd(t, cfg, net.JoinHostPort(defaultHostname, "8125"))
 		})
 
 		t.Run("port", func(t *testing.T) {
 			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-				w.Write([]byte(`{"statsd_port":8999}`))
+				w.Write([]byte(`{"endpoints": [], "config": {"statsd_port":8999}}`))
 			}))
 			defer srv.Close()
-			cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")))
+			cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), withIgnoreAgent(true))
 			testStatsd(t, cfg, net.JoinHostPort(defaultHostname, "8999"))
 		})
 	})
@@ -211,10 +211,10 @@ func TestLoadAgentFeatures(t *testing.T) {
 
 	t.Run("OK", func(t *testing.T) {
 		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-			w.Write([]byte(`{"endpoints":["/v0.6/stats"],"feature_flags":["a","b"],"client_drop_p0s":true,"statsd_port":8999}`))
+			w.Write([]byte(`{"endpoints":["/v0.6/stats"],"feature_flags":["a","b"],"client_drop_p0s":true,"config": {"statsd_port":8999}}`))
 		}))
 		defer srv.Close()
-		cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), WithAgentTimeout(2))
+		cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), WithAgentTimeout(2), withIgnoreAgent(true))
 		assert.True(t, cfg.agent.DropP0s)
 		assert.Equal(t, cfg.agent.StatsdPort, 8999)
 		assert.EqualValues(t, cfg.agent.featureFlags, map[string]struct{}{
@@ -229,10 +229,10 @@ func TestLoadAgentFeatures(t *testing.T) {
 	t.Run("discovery", func(t *testing.T) {
 		t.Setenv("DD_TRACE_FEATURES", "discovery")
 		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-			w.Write([]byte(`{"endpoints":["/v0.6/stats"],"client_drop_p0s":true,"statsd_port":8999}`))
+			w.Write([]byte(`{"endpoints":["/v0.6/stats"],"client_drop_p0s":true,"config":{"statsd_port":8999}}`))
 		}))
 		defer srv.Close()
-		cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), WithAgentTimeout(2))
+		cfg := newConfig(WithAgentAddr(strings.TrimPrefix(srv.URL, "http://")), WithAgentTimeout(2), withIgnoreAgent(true))
 		assert.True(t, cfg.agent.DropP0s)
 		assert.True(t, cfg.agent.Stats)
 		assert.Equal(t, 8999, cfg.agent.StatsdPort)