Refactor log4jX instrumentations

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/log/LogContextScopeListener.java

@@ -7,7 +7,7 @@ import lombok.extern.slf4j.Slf4j;
 
 /**
  * A scope listener that receives the MDC/ThreadContext put and receive methods and update the trace
- * and span reference anytime a new scope is activated.
+ * and span reference anytime a new scope is activated or closed.
  */
 @Slf4j
 public class LogContextScopeListener implements ScopeListener {

dd-java-agent/instrumentation/log4j1/log4j1.gradle

@@ -15,7 +15,7 @@ muzzle {
 configurations {
   // In order to test the real log4j library we need to remove the log4j transitive dependency
   // dependency brought in by :dd-java-agent:testing over 'log4j-over-slf4j' which would shadow
-  // the log4j module under test.
+  // the log4j module under test using a proxy to slf4j instead.
   testCompile.exclude group: 'org.slf4j', module: 'log4j-over-slf4j'
 }
 

dd-java-agent/instrumentation/log4j1/src/main/java/datadog/trace/instrumentation/log4j1/Log4j1MDCInstrumentation.java

@@ -20,21 +20,18 @@ import net.bytebuddy.matcher.ElementMatcher;
 public class Log4j1MDCInstrumentation extends Instrumenter.Default {
   public static final String MDC_INSTRUMENTATION_NAME = "log4j-mdc";
 
-  private static final String mdcClassName = "org.apache.log4j.MDC";
-
   public Log4j1MDCInstrumentation() {
     super(MDC_INSTRUMENTATION_NAME);
   }
 
   @Override
   protected boolean defaultEnabled() {
-    return Config.getBooleanSettingFromEnvironment(
-        Config.LOGS_INJECTION_ENABLED, Config.DEFAULT_LOGS_INJECTION_ENABLED);
+    return Config.get().isLogsInjectionEnabled();
   }
 
   @Override
   public ElementMatcher<? super TypeDescription> typeMatcher() {
-    return named(mdcClassName);
+    return named("org.apache.log4j.MDC");
   }
 
   @Override

dd-java-agent/instrumentation/log4j1/src/main/java/datadoggggg/trace/instrumentation/log4j1/something/SomeClass.java

@@ -1,18 +0,0 @@
-package datadoggggg.trace.instrumentation.log4j1.something;
-
-public class SomeClass {
-
-  private static SomeClass instance = new SomeClass();
-
-  public SomeClass() {
-    System.out.println("SomeClass Constructor.......!!!!!!!");
-  }
-
-  public static void put() {
-    instance.doSomething();
-  }
-
-  public void doSomething() {
-    System.out.println("SomeClass Doing something............");
-  }
-}

dd-java-agent/instrumentation/log4j1/src/test/groovy/Log4j1MDCTest.groovy

@@ -9,7 +9,9 @@ import java.util.concurrent.atomic.AtomicReference
 class Log4j1MDCTest extends AgentTestRunner {
 
   static {
+    ConfigUtils.updateConfig {
       System.setProperty("dd.logs.injection", "true")
+    }
   }
 
   def "MDC shows trace and span ids for active scope"() {

dd-java-agent/instrumentation/log4j2/log4j2.gradle

@@ -7,7 +7,7 @@ ext {
 configurations {
   // In order to test the real log4j library we need to remove the log4j transitive dependency
   // dependency brought in by :dd-java-agent:testing over 'log4j-over-slf4j' which would shadow
-  // the log4j module under test.
+  // the log4j module under test using a proxy to slf4j instead.
   testCompile.exclude group: 'org.slf4j', module: 'log4j-over-slf4j'
 }
 

dd-java-agent/instrumentation/log4j2/src/main/java/datadog/trace/instrumentation/log4j2/ThreadContextInstrumentation.java

@@ -22,21 +22,18 @@ import net.bytebuddy.utility.JavaModule;
 public class ThreadContextInstrumentation extends Instrumenter.Default {
   public static final String MDC_INSTRUMENTATION_NAME = "log4j-thread-context";
 
-  private static final String mdcClassName = "org.apache.logging.log4j.ThreadContext";
-
   public ThreadContextInstrumentation() {
     super(MDC_INSTRUMENTATION_NAME);
   }
 
   @Override
   protected boolean defaultEnabled() {
-    return Config.getBooleanSettingFromEnvironment(
-        Config.LOGS_INJECTION_ENABLED, Config.DEFAULT_LOGS_INJECTION_ENABLED);
+    return Config.get().isLogsInjectionEnabled();
   }
 
   @Override
   public ElementMatcher<? super TypeDescription> typeMatcher() {
-    return named(mdcClassName);
+    return named("org.apache.logging.log4j.ThreadContext");
   }
 
   @Override

dd-java-agent/instrumentation/log4j2/src/test/groovy/Log4jThreadContextTest.groovy

@@ -10,7 +10,9 @@ import java.util.concurrent.atomic.AtomicReference
 class Log4jThreadContextTest extends AgentTestRunner {
 
   static {
+    ConfigUtils.updateConfig {
       System.setProperty("dd.logs.injection", "true")
+    }
   }
 
   def "ThreadContext shows trace and span ids for active scope"() {