Fix NPE when traces collection is disabled

src/main/java/org/datadog/jenkins/plugins/datadog/DatadogClient.java

@@ -142,20 +142,23 @@ public ServiceCheck.Status toServiceCheckStatus(){
      * Start the trace of a certain Jenkins build.
      * @param buildData
      * @param run
+     * @return a boolean to signify the success or failure of the request.
      */
-    void startBuildTrace(BuildData buildData, Run<?, ?> run);
+    boolean startBuildTrace(BuildData buildData, Run<?, ?> run);
 
     /**
      * Finish the trace of a certain Jenkins build.
      * @param buildData
+     * @return a boolean to signify the success or failure of the request.
      */
-    void finishBuildTrace(BuildData buildData, Run<?, ?> run);
+    boolean finishBuildTrace(BuildData buildData, Run<?, ?> run);
 
     /**
      * Send all traces related to a certain Jenkins pipeline.
      * @param run a particular execution of a Jenkins build
      * @param flowNode current flowNode
+     * @return a boolean to signify the success or failure of the request.
      */
-    void sendPipelineTrace(Run<?, ?> run, FlowNode flowNode);
+    boolean sendPipelineTrace(Run<?, ?> run, FlowNode flowNode);
 
 }

src/main/java/org/datadog/jenkins/plugins/datadog/clients/DatadogHttpClient.java

@@ -657,18 +657,21 @@ private String getJenkinsVersion(){
     }
 
     @Override
-    public void startBuildTrace(BuildData buildData, Run run) {
+    public boolean startBuildTrace(BuildData buildData, Run run) {
         logger.fine("Traces are only available using Datadog Agent.");
+        return false;
     }
 
     @Override
-    public void finishBuildTrace(BuildData buildData, Run<?, ?> run) {
+    public boolean finishBuildTrace(BuildData buildData, Run<?, ?> run) {
         logger.fine("Traces are only available using Datadog Agent.");
+        return false;
     }
 
     @Override
-    public void sendPipelineTrace(Run<?, ?> run, FlowNode flowNode) {
+    public boolean sendPipelineTrace(Run<?, ?> run, FlowNode flowNode) {
         logger.fine("Traces are only available using Datadog Agent.");
+        return false;
     }
 
 }

src/main/java/org/datadog/jenkins/plugins/datadog/clients/DogStatsDClient.java

@@ -474,18 +474,57 @@ public boolean sendLogs(String payload) {
     }
 
     @Override
-    public void startBuildTrace(BuildData buildData, Run<?, ?> run) {
-        traceBuildLogic.startBuildTrace(buildData, run);
+    public boolean startBuildTrace(BuildData buildData, Run<?, ?> run) {
+        try {
+            boolean status = reinitializeTracer(false);
+            if(!status) {
+                return false;
+            }
+
+            logger.fine("Started build trace");
+            this.traceBuildLogic.startBuildTrace(buildData, run);
+            return true;
+        } catch (Exception e) {
+            DatadogUtilities.severe(logger, e, null);
+            reinitializeTracer(true);
+            return false;
+        }
     }
 
+
     @Override
-    public void finishBuildTrace(BuildData buildData, Run<?, ?> run) {
-        traceBuildLogic.finishBuildTrace(buildData, run);
+    public boolean finishBuildTrace(BuildData buildData, Run<?, ?> run) {
+        try {
+            boolean status = reinitializeTracer(false);
+            if(!status) {
+                return false;
+            }
+            logger.fine("Finished build trace");
+            this.traceBuildLogic.finishBuildTrace(buildData, run);
+            return true;
+        } catch (Exception e) {
+            DatadogUtilities.severe(logger, e, null);
+            reinitializeTracer(true);
+            return false;
+        }
     }
 
     @Override
-    public void sendPipelineTrace(Run<?, ?> run, FlowNode flowNode) {
-        tracePipelineLogic.execute(run, flowNode);
+    public boolean sendPipelineTrace(Run<?, ?> run, FlowNode flowNode) {
+        try {
+            boolean status = reinitializeTracer(false);
+            if(!status) {
+                return false;
+            }
+
+            logger.fine("Send pipeline traces.");
+            this.tracePipelineLogic.execute(run, flowNode);
+            return true;
+        } catch (Exception e){
+            DatadogUtilities.severe(logger, e, null);
+            reinitializeTracer(true);
+            return false;
+        }
     }
 
 

src/test/java/org/datadog/jenkins/plugins/datadog/clients/DatadogClientStub.java

@@ -172,18 +172,21 @@ public boolean sendLogs(String payloadLogs) {
     }
 
     @Override
-    public void startBuildTrace(BuildData buildData, Run<?, ?> run) {
+    public boolean startBuildTrace(BuildData buildData, Run<?, ?> run) {
         this.traceBuildLogic.startBuildTrace(buildData, run);
+        return true;
     }
 
     @Override
-    public void finishBuildTrace(BuildData buildData, Run<?, ?> run) {
+    public boolean finishBuildTrace(BuildData buildData, Run<?, ?> run) {
         this.traceBuildLogic.finishBuildTrace(buildData, run);
+        return true;
     }
 
     @Override
-    public void sendPipelineTrace(Run<?, ?> run, FlowNode flowNode) {
+    public boolean sendPipelineTrace(Run<?, ?> run, FlowNode flowNode) {
         this.tracePipelineLogic.execute(run, flowNode);
+        return true;
     }
 
     public ListWriter tracerWriter() {