From 9159627434955e8d36e0bf1ffaf9ad3b27331158 Mon Sep 17 00:00:00 2001
From: Tony Redondo <tony.redondo@datadoghq.com>
Date: Tue, 10 Dec 2024 23:25:53 +0100
Subject: [PATCH] [v2] fix(ddtrace/tracer): Disable agent features and remote
 configuration in CI Visibility agentless mode

---
 ddtrace/tracer/option.go | 26 +++++++++++++-------------
 ddtrace/tracer/tracer.go | 13 +++++++++++++
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/ddtrace/tracer/option.go b/ddtrace/tracer/option.go
index afba52a0d8..9377dea837 100644
--- a/ddtrace/tracer/option.go
+++ b/ddtrace/tracer/option.go
@@ -531,8 +531,19 @@ func newConfig(opts ...StartOption) (*config, error) {
 	if c.debug {
 		log.SetLevel(log.LevelDebug)
 	}
-	// if using stdout or traces are disabled, agent is disabled
-	agentDisabled := c.logToStdout || !c.enabled.current
+
+	// Check if CI Visibility mode is enabled
+	if internal.BoolEnv(constants.CIVisibilityEnabledEnvironmentVariable, false) {
+		c.ciVisibilityEnabled = true               // Enable CI Visibility mode
+		c.httpClientTimeout = time.Second * 45     // Increase timeout up to 45 seconds (same as other tracers in CIVis mode)
+		c.logStartup = false                       // If we are in CI Visibility mode we don't want to log the startup to stdout to avoid polluting the output
+		ciTransport := newCiVisibilityTransport(c) // Create a default CI Visibility Transport
+		c.transport = ciTransport                  // Replace the default transport with the CI Visibility transport
+		c.ciVisibilityAgentless = ciTransport.agentless
+	}
+
+	// if using stdout or traces are disabled, or we are in ci visibility agentless mode, agent is disabled
+	agentDisabled := c.logToStdout || !c.enabled.current || c.ciVisibilityAgentless
 	c.agent = loadAgentFeatures(agentDisabled, c.agentURL, c.httpClient)
 	info, ok := debug.ReadBuildInfo()
 	if !ok {
@@ -550,17 +561,6 @@ func newConfig(opts ...StartOption) (*config, error) {
 	// This allows persisting the initial value of globalTags for future resets and updates.
 	globalTagsOrigin := c.globalTags.cfgOrigin
 	c.initGlobalTags(c.globalTags.get(), globalTagsOrigin)
-
-	// Check if CI Visibility mode is enabled
-	if internal.BoolEnv(constants.CIVisibilityEnabledEnvironmentVariable, false) {
-		c.ciVisibilityEnabled = true               // Enable CI Visibility mode
-		c.httpClientTimeout = time.Second * 45     // Increase timeout up to 45 seconds (same as other tracers in CIVis mode)
-		c.logStartup = false                       // If we are in CI Visibility mode we don't want to log the startup to stdout to avoid polluting the output
-		ciTransport := newCiVisibilityTransport(c) // Create a default CI Visibility Transport
-		c.transport = ciTransport                  // Replace the default transport with the CI Visibility transport
-		c.ciVisibilityAgentless = ciTransport.agentless
-	}
-
 	return c, nil
 }
 
diff --git a/ddtrace/tracer/tracer.go b/ddtrace/tracer/tracer.go
index bd28385f2d..fdaf9d808a 100644
--- a/ddtrace/tracer/tracer.go
+++ b/ddtrace/tracer/tracer.go
@@ -203,6 +203,19 @@ func Start(opts ...StartOption) error {
 	if t.dataStreams != nil {
 		t.dataStreams.Start()
 	}
+	if t.config.ciVisibilityAgentless {
+		// CI Visibility agentless mode doesn't require remote configuration.
+
+		// start instrumentation telemetry unless it is disabled through the
+		// DD_INSTRUMENTATION_TELEMETRY_ENABLED env var
+		startTelemetry(t.config)
+
+		// start appsec
+		appsec.Start(t.config.appsecStartOptions...)
+		globalinternal.SetTracerInitialized(true)
+		return nil
+	}
+
 	// Start AppSec with remote configuration
 	cfg := remoteconfig.DefaultClientConfig()
 	cfg.AgentURL = t.config.agentURL.String()