Moving resolver in agent

dd-java-agent/src/main/java/com/datadoghq/trace/resolver/AgentTracerConfig.java

@@ -0,0 +1,17 @@
+package com.datadoghq.trace.resolver;
+
+/**
+ * Configuration POJO for the agent
+ */
+public class AgentTracerConfig extends TracerConfig {
+
+	private boolean enableCustomTracing = false;
+
+	public boolean isEnableCustomTracing() {
+		return enableCustomTracing;
+	}
+
+	public void setEnableCustomTracing(boolean enableCustomTracing) {
+		this.enableCustomTracing = enableCustomTracing;
+	}
+}

dd-java-agent/src/main/java/com/datadoghq/trace/resolver/DDTracerResolver.java

@@ -0,0 +1,62 @@
+package com.datadoghq.trace.resolver;
+
+import java.util.List;
+import java.util.ServiceLoader;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.datadoghq.trace.DDTracer;
+import com.datadoghq.trace.integration.DDSpanContextDecorator;
+import com.google.auto.service.AutoService;
+
+import io.opentracing.NoopTracerFactory;
+import io.opentracing.Tracer;
+import io.opentracing.contrib.tracerresolver.TracerResolver;
+import io.opentracing.util.GlobalTracer;
+
+
+@AutoService(TracerResolver.class)
+public class DDTracerResolver extends TracerResolver {
+
+	private final static Logger logger = LoggerFactory.getLogger(DDTracerResolver.class);
+
+	@Override
+	protected Tracer resolve() {
+		logger.info("Creating the Datadog tracer");
+
+		//Find a resource file named dd-trace.yml
+		DDTracer tracer = null;
+		//Create tracer from resource files
+		tracer = DDTracerFactory.createFromResources();
+
+		//Create decorators from resource files
+		List<DDSpanContextDecorator> decorators = DDDecoratorsFactory.createFromResources();
+		for(DDSpanContextDecorator decorator : decorators){
+			tracer.addDecorator(decorator);
+		}
+
+		return tracer;
+	}
+
+	@SuppressWarnings("static-access")
+	public static Tracer registerTracer() {
+
+		ServiceLoader<TracerResolver> RESOLVERS = ServiceLoader.load(TracerResolver.class);
+
+		Tracer tracer = null;
+		for (TracerResolver value : RESOLVERS) {
+			tracer = value.resolveTracer();
+			if (tracer != null) {
+				break;
+			}
+		}
+
+		if (tracer == null) {
+			tracer = NoopTracerFactory.create();
+		}
+
+		GlobalTracer.register(tracer);
+		return tracer;
+	}
+}

dd-trace/src/main/java/com/datadoghq/trace/resolver/DDDecoratorsFactory.java

@@ -1,12 +1,17 @@
 package com.datadoghq.trace.resolver;
 
+import java.io.IOException;
+import java.net.URL;
 import java.util.ArrayList;
+import java.util.Enumeration;
 import java.util.List;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import com.datadoghq.trace.integration.DDSpanContextDecorator;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 
 /**
  * Create DDSpaDecorators from a valid configuration
@@ -17,6 +22,10 @@ public class DDDecoratorsFactory {
 
 	public static String DECORATORS_PACKAGE = "com.datadoghq.trace.integration.";
 
+	public static final String CONFIG_PATH = "dd-trace-decorators.yaml";
+
+	private static final ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory());
+
 	/**
 	 * Create decorators from configuration
 	 * 
@@ -39,7 +48,7 @@ public class DDDecoratorsFactory {
 				logger.warn("Cannot create decorator as the class {} is not defined. Provided configuration {}",decoratorConfig);
 				continue;
 			}
-			
+
 			DDSpanContextDecorator decorator = null;
 			try{
 				decorator = (DDSpanContextDecorator) decoratorClass.getConstructor().newInstance();
@@ -47,7 +56,7 @@ public class DDDecoratorsFactory {
 				logger.warn("Cannot create decorator as we could not invoke the default constructor. Provided configuration {}",decoratorConfig);
 				continue;
 			}
-			
+
 			//Fill with config values
 			if(decoratorConfig.getMatchingTag()!=null){
 				decorator.setMatchingTag(decoratorConfig.getMatchingTag());
@@ -61,9 +70,29 @@ public class DDDecoratorsFactory {
 			if(decoratorConfig.getSetValue()!=null){
 				decorator.setSetValue(decoratorConfig.getSetValue());
 			}
-			
+
 			decorators.add(decorator);
 		}
 		return decorators;
 	}
+
+	public static List<DDSpanContextDecorator> createFromResources(){
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+
+		List<DDSpanContextDecorator> result = new ArrayList<DDSpanContextDecorator>();
+		try{
+			Enumeration<URL> iter = classLoader.getResources(CONFIG_PATH);
+			while (iter.hasMoreElements()) {
+				TracerConfig config = objectMapper.readValue(iter.nextElement().openStream(), TracerConfig.class);
+				result = DDDecoratorsFactory.create(config.getDecorators());
+				
+				break; // ONLY the closest resource file is taken into account
+			}
+		}catch(IOException e){
+			logger.error("Could not load decorators configuration file.", e);
+		}
+
+
+		return result;
+	}
 }

dd-trace/src/main/java/com/datadoghq/trace/resolver/DDSpanDecoratorConfig.java

@@ -4,9 +4,6 @@ import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 
-/**
- * 
- */
 public class DDSpanDecoratorConfig {
 	
 	private String type;

dd-trace/src/main/java/com/datadoghq/trace/resolver/DDTracerFactory.java

@@ -1,5 +1,12 @@
 package com.datadoghq.trace.resolver;
 
+import java.io.IOException;
+import java.net.URL;
+import java.util.Enumeration;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import com.datadoghq.trace.DDTracer;
 import com.datadoghq.trace.sampling.AllSampler;
 import com.datadoghq.trace.sampling.RateSampler;
@@ -8,12 +15,20 @@ 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;
 
 /**
  * Create a tracer from a configuration file
  */
 public class DDTracerFactory {
-	
+
+	private final static Logger logger = LoggerFactory.getLogger(DDTracerFactory.class);
+
+	public static final String CONFIG_PATH = "dd-trace.yaml";
+	private static final ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory());
+
+
 	/**
 	 * Create a tracer from a TracerConfig object
 	 * 
@@ -52,4 +67,27 @@ public class DDTracerFactory {
 		return new DDTracer(defaultServiceName, writer, rateSampler);
 	}
 	
+	public static DDTracer createFromResources(){
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+		DDTracer tracer = null;
+		try {
+			Enumeration<URL> iter = classLoader.getResources(CONFIG_PATH);
+			while (iter.hasMoreElements()) {
+				TracerConfig config = objectMapper.readValue(iter.nextElement().openStream(), TracerConfig.class);
+
+				tracer = DDTracerFactory.create(config);
+
+				break; // ONLY the closest resource file is taken into account
+			}
+		} catch (IOException e) {
+			logger.error("Could not load tracer configuration file.", e);
+		}
+
+		if (tracer == null) {
+			logger.info("No valid configuration file {} found. Loading default tracer.",CONFIG_PATH);
+			tracer = new DDTracer();
+		}
+		return tracer;
+	}
+
 }

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

@@ -1,94 +0,0 @@
-package com.datadoghq.trace.resolver;
-
-import java.io.IOException;
-import java.net.URL;
-import java.util.Enumeration;
-import java.util.ServiceLoader;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.datadoghq.trace.DDTracer;
-import com.datadoghq.trace.integration.DDSpanContextDecorator;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
-import com.google.auto.service.AutoService;
-
-import io.opentracing.NoopTracerFactory;
-import io.opentracing.Tracer;
-import io.opentracing.contrib.tracerresolver.TracerResolver;
-import io.opentracing.util.GlobalTracer;
-
-
-@AutoService(TracerResolver.class)
-public class DDTracerResolver extends TracerResolver {
-
-	private final static Logger logger = LoggerFactory.getLogger(DDTracerResolver.class);
-
-	public static final String TRACER_CONFIG = "dd-trace.yaml";
-	public static final String DECORATORS_CONFIG = "dd-trace-decorators.yaml";
-
-	private final ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory());
-
-	@Override
-	protected Tracer resolve() {
-		logger.info("Creating the Datadog tracer");
-
-		//Find a resource file named dd-trace.yml
-		DDTracer tracer = null;
-		try {
-			ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
-			Enumeration<URL> iter = classLoader.getResources(TRACER_CONFIG);
-			while (iter.hasMoreElements()) {
-				TracerConfig config = objectMapper.readValue(iter.nextElement().openStream(), TracerConfig.class);
-
-				tracer = DDTracerFactory.create(config);
-
-				break; // ONLY the closest resource file is taken into account
-			}
-
-			iter = classLoader.getResources(DECORATORS_CONFIG);
-			while (iter.hasMoreElements()) {
-				TracerConfig config = objectMapper.readValue(iter.nextElement().openStream(), TracerConfig.class);
-				//Find decorators
-				if (config.getDecorators() != null) {
-					for(DDSpanContextDecorator decorator:DDDecoratorsFactory.create(config.getDecorators())){
-						tracer.addDecorator(decorator);
-					}
-				}
-				
-				break; // ONLY the closest resource file is taken into account
-			}
-		} 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;
-	}
-
-	@SuppressWarnings("static-access")
-	public static Tracer registerTracer() {
-
-		ServiceLoader<TracerResolver> RESOLVERS = ServiceLoader.load(TracerResolver.class);
-
-		Tracer tracer = null;
-		for (TracerResolver value : RESOLVERS) {
-			tracer = value.resolveTracer();
-			if (tracer != null) {
-				break;
-			}
-		}
-
-		if (tracer == null) {
-			tracer = NoopTracerFactory.create();
-		}
-
-		GlobalTracer.register(tracer);
-		return tracer;
-	}
-}