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

145 lines
5.0 KiB
Java

package com.datadoghq.trace.resolver;
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.DB;
import com.datadoghq.trace.integration.DDSpanContextDecorator;
import com.datadoghq.trace.integration.HTTP;
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.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);
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);
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 (Map<String, Object> map : config.getDecorators()) {
if (map.get("type") != null) {
DDSpanContextDecorator decorator = null;
String componentName = (String) map.get("componentName");
String desiredServiceName = (String) map.get("desiredServiceName");
if (map.get("type").equals(HTTP.class.getSimpleName())) {
decorator = new HTTP(componentName, desiredServiceName);
tracer.addDecorator(decorator);
} else if (map.get("type").equals(DB.class.getSimpleName())) {
decorator = new DB(componentName, desiredServiceName);
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;
}
}