Added dd-trace.yaml config file resolution in resolver + default service name in tracer

pom.xml

@@ -18,6 +18,11 @@
 			<artifactId>jackson-databind</artifactId>
 			<version>2.8.8</version>
 		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.dataformat</groupId>
+			<artifactId>jackson-dataformat-yaml</artifactId>
+			<version>2.8.8</version>
+		</dependency>
 		
 		<!-- Logging dependencies -->
 		<dependency>
@@ -40,7 +45,7 @@
 		<dependency>
 			<groupId>io.opentracing.contrib</groupId>
 			<artifactId>opentracing-tracerresolver</artifactId>
-            <version>0.0.3</version>
+			<version>0.1.0</version>
 		</dependency>
 
 		<dependency>

src/main/java/com/datadoghq/trace/DDTracer.java

@@ -14,7 +14,7 @@ import com.datadoghq.trace.propagation.Codec;
 import com.datadoghq.trace.propagation.HTTPCodec;
 import com.datadoghq.trace.sampling.AllSampler;
 import com.datadoghq.trace.sampling.Sampler;
-import com.datadoghq.trace.writer.LoggingWritter;
+import com.datadoghq.trace.writer.DDAgentWriter;
 import com.datadoghq.trace.writer.Writer;
 
 import io.opentracing.Span;
@@ -36,6 +36,11 @@ public class DDTracer implements io.opentracing.Tracer {
      */
     private final Sampler sampler;
     
+    /**
+     * Default service name if none provided on the trace or span
+     */
+    private final String defaultServiceName;
+
     /**
      * Span context decorators
      */
@@ -45,15 +50,29 @@ public class DDTracer implements io.opentracing.Tracer {
     private final static Logger logger = LoggerFactory.getLogger(DDTracer.class);
     private final CodecRegistry registry;
     
+    public static final String UNASSIGNED_DEFAULT_SERVICE_NAME = "unnamed-java-app";
+    public static final Writer UNASSIGNED_WRITER = new DDAgentWriter();
+    public static final Sampler UNASSIGNED_SAMPLER = new AllSampler();
+
     /**
      * Default constructor, trace/spans are logged, no trace/span dropped
      */
     public DDTracer() {
-        this(new LoggingWritter(), new AllSampler());
+        this(UNASSIGNED_WRITER);
+    }
+    
+    public DDTracer(Writer writer) {
+        this(writer, new AllSampler());
     }
 
     public DDTracer(Writer writer, Sampler sampler) {
+        this(UNASSIGNED_DEFAULT_SERVICE_NAME,writer,sampler);
+    }
+    
+    public DDTracer(String defaultServiceName,Writer writer, Sampler sampler) {
+    	this.defaultServiceName = defaultServiceName;
         this.writer = writer;
+        this.writer.start();
         this.sampler = sampler;
         registry = new CodecRegistry();
         registry.register(Format.Builtin.HTTP_HEADERS, new HTTPCodec());
@@ -261,8 +280,12 @@ public class DDTracer implements io.opentracing.Tracer {
             }
 
             String serviceName = this.serviceName;
-            if (serviceName == null && this.parent != null) {
+            if (serviceName == null) {
+                if(p != null){
                 	serviceName = p.getServiceName();
+                }else{
+                	serviceName = defaultServiceName;
+                }
             }
 
             //this.operationName, this.tags,

src/main/java/com/datadoghq/trace/integration/DBServiceDecorator.java

@@ -40,4 +40,12 @@ public class DBServiceDecorator implements DDSpanContextDecorator {
 			context.setResourceName(String.valueOf(value));
 		}
 	}
+	
+	public String getComponentName() {
+		return componentName;
+	}
+
+	public String getDesiredServiceName() {
+		return desiredServiceName;
+	}
 }

src/main/java/com/datadoghq/trace/integration/HTTPServiceDecorator.java

@@ -48,4 +48,12 @@ public class HTTPServiceDecorator implements DDSpanContextDecorator {
 			}
 		}
 	}
+	
+	public String getComponentName() {
+		return componentName;
+	}
+
+	public String getDesiredServiceName() {
+		return desiredServiceName;
+	}
 }

src/main/java/com/datadoghq/trace/resolver/DDTracerResolver.java

@@ -1,9 +1,30 @@
 package com.datadoghq.trace.resolver;
 
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Enumeration;
+import java.util.Map;
+import java.util.ServiceLoader;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import com.datadoghq.trace.DDTracer;
+import com.datadoghq.trace.integration.DBServiceDecorator;
+import com.datadoghq.trace.integration.DDSpanContextDecorator;
+import com.datadoghq.trace.integration.HTTPServiceDecorator;
 import com.datadoghq.trace.sampling.AllSampler;
+import com.datadoghq.trace.sampling.RateSampler;
+import com.datadoghq.trace.sampling.Sampler;
 import com.datadoghq.trace.writer.DDAgentWriter;
+import com.datadoghq.trace.writer.DDApi;
+import com.datadoghq.trace.writer.LoggingWritter;
+import com.datadoghq.trace.writer.Writer;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import com.google.auto.service.AutoService;
+
 import io.opentracing.Tracer;
 import io.opentracing.contrib.tracerresolver.TracerResolver;
 
@@ -11,9 +32,97 @@ import io.opentracing.contrib.tracerresolver.TracerResolver;
 @AutoService(TracerResolver.class)
 public class DDTracerResolver extends TracerResolver{
 
+	private final static Logger logger = LoggerFactory.getLogger(DDTracerResolver.class);
+	
+//	private static final ServiceLoader<Writer> WRITERS = ServiceLoader.load(Writer.class);
+//	private static final ServiceLoader<Sampler> SAMPLERS = ServiceLoader.load(Sampler.class);
+//	private static final ServiceLoader<DDSpanContextDecorator> DECORATORS = ServiceLoader.load(DDSpanContextDecorator.class);
+	
+	public static final String TRACER_CONFIG = "dd-trace.yaml";
+	private final ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory());
+	
     @Override
     protected Tracer resolve() {
-        // TODO find a way to close the reader ...
-        return new DDTracer(new DDAgentWriter(), new AllSampler());
+    	logger.info("Creating the Datadog tracer");
+    	
+    	//Find a resource file named dd-trace.yml
+    	DDTracer tracer = null;
+    	try {
+			Enumeration<URL> iter = Thread.currentThread().getContextClassLoader().getResources(TRACER_CONFIG);
+			while (iter.hasMoreElements()) {
+				
+				TracerConfig config = objectMapper.readValue(new File(iter.nextElement().getFile()),TracerConfig.class);
+				
+				String defaultServiceName = config.getDefaultServiceName()!=null?config.getDefaultServiceName():DDTracer.UNASSIGNED_DEFAULT_SERVICE_NAME;
+				
+				//Create writer
+				Writer writer = DDTracer.UNASSIGNED_WRITER;
+				if(config.getWriter()!=null &&config.getWriter().get("type")!=null){
+					String type = (String) config.getWriter().get("type");
+					if(type.equals(DDAgentWriter.class.getSimpleName())){
+						String host = config.getWriter().get("host")!=null?(String)config.getWriter().get("host"):DDAgentWriter.DEFAULT_HOSTNAME;
+						Integer port = config.getWriter().get("port")!=null?(Integer)config.getWriter().get("port"):DDAgentWriter.DEFAULT_PORT;
+						DDApi api = new DDApi(host, port);
+						writer = new DDAgentWriter(api);
+					}else if(type.equals(LoggingWritter.class.getSimpleName())){
+						writer = new LoggingWritter();
+					}
+				}
+				
+				//Create sampler
+				Sampler rateSampler = DDTracer.UNASSIGNED_SAMPLER;
+				if(config.getSampler()!=null && config.getSampler().get("type")!=null){
+					String type = (String) config.getSampler().get("type");
+					if(type.equals(AllSampler.class.getSimpleName())){
+						rateSampler = new AllSampler();
+					}else if(type.equals(RateSampler.class.getSimpleName())){
+						rateSampler = new RateSampler((Double)config.getSampler().get("rate"));
+					}
+				}
+				
+				//Create tracer
+				tracer = new DDTracer(defaultServiceName,writer,rateSampler);
+				
+				//Find decorators
+				if(config.getDecorators()!=null){
+					for(Map<String,Object> map : config.getDecorators()){
+						if(map.get("type")!=null){
+							DDSpanContextDecorator decorator = null;
+							String componentName = (String) map.get("componentName");
+							String desiredServiceName = map.get("desiredServiceName")!=null?(String) map.get("desiredServiceName"):(String) map.get("componentName");
+							
+							if(map.get("type").equals(HTTPServiceDecorator.class.getSimpleName())){
+								decorator = new HTTPServiceDecorator(componentName,desiredServiceName);
+								tracer.addDecorator(decorator);
+							}else if(map.get("type").equals(DBServiceDecorator.class.getSimpleName())){
+								decorator = new DBServiceDecorator(componentName,desiredServiceName);
+								tracer.addDecorator(decorator);
+							}
+						}
+					}
+				}
+				
+				break;
+			}
+		} catch (IOException e) {
+			logger.error("Could not load tracer configuration file. Loading default tracer.",e);
+		}
+    	
+    	if(tracer==null){
+    		logger.info("No valid configuration file 'dd-trace.yaml' found. Loading default tracer.");
+    		tracer = new DDTracer();
+    	}
+    	
+        return tracer;
+    }
+    
+    
+   
+    public static void main(String[] args){
+    	 ServiceLoader<TracerResolver> RESOLVERS = ServiceLoader.load(TracerResolver.class);
+         
+         for (TracerResolver value : RESOLVERS){
+        	 value.resolveTracer();
+         }
     }
 }

src/main/java/com/datadoghq/trace/resolver/TracerConfig.java

@@ -0,0 +1,39 @@
+package com.datadoghq.trace.resolver;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Tracer configuration
+ */
+public class TracerConfig {
+	private String defaultServiceName;
+	private Map<String,Object> writer;
+	private Map<String,Object> sampler;
+	private List<Map<String,Object>> decorators;
+	
+	public String getDefaultServiceName() {
+		return defaultServiceName;
+	}
+	public void setDefaultServiceName(String defaultServiceName) {
+		this.defaultServiceName = defaultServiceName;
+	}
+	public Map<String, Object> getWriter() {
+		return writer;
+	}
+	public void setWriter(Map<String, Object> writer) {
+		this.writer = writer;
+	}
+	public Map<String, Object> getSampler() {
+		return sampler;
+	}
+	public void setSampler(Map<String, Object> sampler) {
+		this.sampler = sampler;
+	}
+	public List<Map<String, Object>> getDecorators() {
+		return decorators;
+	}
+	public void setDecorators(List<Map<String, Object>> decorators) {
+		this.decorators = decorators;
+	}
+}

src/main/java/com/datadoghq/trace/sampling/RateSampler.java

@@ -1,10 +1,13 @@
 package com.datadoghq.trace.sampling;
 
 
-import io.opentracing.Span;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.auto.service.AutoService;
+
+import io.opentracing.Span;
+
 
 /**
  * This sampler sample the traces at a predefined rate.
@@ -12,6 +15,7 @@ import org.slf4j.LoggerFactory;
  * Keep (100 * `sample_rate`)% of the traces.
  * It samples randomly, its main purpose is to reduce the instrumentation footprint.
  */
+@AutoService(Sampler.class)
 public class RateSampler implements Sampler {
 
 

src/main/java/com/datadoghq/trace/writer/DDAgentWriter.java

@@ -4,6 +4,8 @@ import io.opentracing.Span;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.auto.service.AutoService;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.*;
@@ -14,6 +16,7 @@ import java.util.concurrent.*;
  * It handles writes asynchronuously so the calling threads are automatically released. However, if too much spans are collected
  * the writers can reach a state where it is forced to drop incoming spans.
  */
+@AutoService(Writer.class)
 public class DDAgentWriter implements Writer {
 
     private static final Logger logger = LoggerFactory.getLogger(DDAgentWriter.class.getName());
@@ -21,8 +24,8 @@ public class DDAgentWriter implements Writer {
     /**
      * Default location of the DD agent
      */
-    private static final String DEFAULT_HOSTNAME = "localhost";
-    private static final int DEFAULT_PORT = 8126;
+    public static final String DEFAULT_HOSTNAME = "localhost";
+    public static final int DEFAULT_PORT = 8126;
 
     /**
      * Maximum number of spans kept in memory
@@ -64,9 +67,6 @@ public class DDAgentWriter implements Writer {
 
         tokens = new Semaphore(DEFAULT_MAX_SPANS);
         traces = new ArrayBlockingQueue<List<Span>>(DEFAULT_MAX_SPANS);
-
-        executor.submit(new SpansSendingTask());
-
     }
 
     /* (non-Javadoc)
@@ -83,6 +83,14 @@ public class DDAgentWriter implements Writer {
         }
     }
     
+    /* (non-Javadoc)
+     * @see com.datadoghq.trace.writer.Writer#start()
+     */
+    @Override
+	public void start() {
+    	executor.submit(new SpansSendingTask());
+	}
+
     /* (non-Javadoc)
      * @see com.datadoghq.trace.Writer#close()
      */

src/main/java/com/datadoghq/trace/writer/LoggingWritter.java

@@ -5,8 +5,11 @@ import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.auto.service.AutoService;
+
 import io.opentracing.Span;
 
+@AutoService(Writer.class)
 public class LoggingWritter implements Writer{
 
 	private static final Logger logger = LoggerFactory.getLogger(LoggingWritter.class.getName());
@@ -20,4 +23,9 @@ public class LoggingWritter implements Writer{
 	public void close() {
 		logger.info("close()");
 	}
+
+	@Override
+	public void start() {
+		logger.info("start()");
+	}
 }

src/main/java/com/datadoghq/trace/writer/Writer.java

@@ -16,6 +16,11 @@ public interface Writer {
      */
     void write(List<Span> trace);
     
+    /**
+     * Start the writer
+     */
+    void start();
+
     /**
      * Indicates to the writer that no future writing will come and it should terminates all connections and tasks
      */

src/test/java/com/datadoghq/trace/DDSpanTest.java

@@ -59,9 +59,10 @@ public class DDSpanTest {
 
         final String expectedName = "operationName";
 
-        DDSpan span = new DDTracer().buildSpan(expectedName).withServiceName("foo").start();
+        DDSpan span = new DDTracer().buildSpan(expectedName).start();
         // ResourceName = expectedName
         assertThat(span.getResourceName()).isEqualTo(expectedName);
+        assertThat(span.getServiceName()).isEqualTo(DDTracer.UNASSIGNED_DEFAULT_SERVICE_NAME);
 
         // ResourceName = expectedResourceName
         final String expectedResourceName = "fake";
@@ -71,6 +72,7 @@ public class DDSpanTest {
                 .withServiceName("foo").start();
 
         assertThat(span.getResourceName()).isEqualTo(expectedResourceName);
+        assertThat(span.getServiceName()).isEqualTo("foo");
 
     }
 

src/test/java/com/datadoghq/trace/resolver/TracerResolverTest.java

@@ -0,0 +1,30 @@
+package com.datadoghq.trace.resolver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.List;
+
+import org.junit.Test;
+
+import com.datadoghq.trace.DDTracer;
+import com.datadoghq.trace.integration.DDSpanContextDecorator;
+import com.datadoghq.trace.integration.HTTPServiceDecorator;
+
+public class TracerResolverTest {
+
+	@Test
+	public void test() {
+		DDTracerResolver tracerResolver = new DDTracerResolver();
+		DDTracer tracer = (DDTracer) tracerResolver.resolve();
+		
+		List<DDSpanContextDecorator> decorators = tracer.getSpanContextDecorators();
+		
+		assertThat(decorators.size()).isEqualTo(1);
+		DDSpanContextDecorator decorator = decorators.get(0);
+		assertThat(decorator.getClass()).isEqualTo(HTTPServiceDecorator.class);
+		HTTPServiceDecorator httpServiceDecorator = (HTTPServiceDecorator) decorator;
+		assertThat(httpServiceDecorator.getComponentName()).isEqualTo("hello");
+		assertThat(httpServiceDecorator.getDesiredServiceName()).isEqualTo("world");
+	}
+
+}

src/test/java/com/datadoghq/trace/writer/impl/DDAgentWriterTest.java

@@ -47,6 +47,7 @@ public class DDAgentWriterTest {
 		mockedAPI = mock(DDApi.class);
 		when(mockedAPI.sendTraces(traces)).thenReturn(true);
 		ddAgentWriter = new DDAgentWriter(mockedAPI);
+		ddAgentWriter.start();
 	}
 
 	@Test

src/test/resources/dd-trace.yaml

@@ -0,0 +1,13 @@
+defaultServiceName: java-app
+writer:
+  type: DDAgentWriter
+  host: localhost
+  port: 10000
+sampler:
+  type: AllSampler
+decorators:
+  - type: HTTPServiceDecorator
+    componentName: hello
+    desiredServiceName: world
+    
+