diff --git a/src/main/java/com/google/cloud/logging/logback/TraceLoggingEventEnhancer.java b/src/main/java/com/google/cloud/logging/logback/TraceLoggingEventEnhancer.java new file mode 100644 index 000000000..e9cd8c5b8 --- /dev/null +++ b/src/main/java/com/google/cloud/logging/logback/TraceLoggingEventEnhancer.java @@ -0,0 +1,55 @@ +/* + * Copyright 2020 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.cloud.logging.logback; + +import ch.qos.logback.classic.spi.ILoggingEvent; +import com.google.cloud.logging.LogEntry; +import org.slf4j.MDC; + +/** Adds support for grouping logs by incoming http request */ +public class TraceLoggingEventEnhancer implements LoggingEventEnhancer { + + // A key used by Cloud Logging for trace Id + private static final String TRACE_ID = "logging.googleapis.trace"; + + /** + * Set the Trace ID associated with any logging done by the current thread. + * + * @param id The traceID, in the form projects/[PROJECT_ID]/traces/[TRACE_ID] + */ + public static void setCurrentTraceId(String id) { + MDC.put(TRACE_ID, id); + } + + /** + * Get the Trace ID associated with any logging done by the current thread. + * + * @return id The traceID + */ + public static String getCurrentTraceId() { + return MDC.get(TRACE_ID); + } + + @Override + public void enhanceLogEntry(LogEntry.Builder builder, ILoggingEvent e) { + Object value = e.getMDCPropertyMap().get(TRACE_ID); + String traceId = value != null ? value.toString() : null; + if (traceId != null) { + builder.setTrace(traceId); + } + } +} diff --git a/src/test/java/com/google/cloud/logging/logback/TraceLoggingEventEnhancerTest.java b/src/test/java/com/google/cloud/logging/logback/TraceLoggingEventEnhancerTest.java new file mode 100644 index 000000000..4de358073 --- /dev/null +++ b/src/test/java/com/google/cloud/logging/logback/TraceLoggingEventEnhancerTest.java @@ -0,0 +1,64 @@ +/* + * Copyright 2020 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.cloud.logging.logback; + +import static com.google.common.truth.Truth.assertThat; + +import ch.qos.logback.classic.spi.LoggingEvent; +import com.google.cloud.logging.LogEntry; +import com.google.cloud.logging.Payload.StringPayload; +import org.junit.Before; +import org.junit.Test; + +public class TraceLoggingEventEnhancerTest { + private TraceLoggingEventEnhancer classUnderTest; + + @Before + public void setUp() { + classUnderTest = new TraceLoggingEventEnhancer(); + } + + @Test + public void testEnhanceLogEntry() { + // setup + String traceId = "abc"; + TraceLoggingEventEnhancer.setCurrentTraceId(traceId); + LoggingEvent loggingEvent = new LoggingEvent(); + loggingEvent.setMessage("this is a test"); + LogEntry.Builder builder = LogEntry.newBuilder(StringPayload.of("this is a test")); + + // act + classUnderTest.enhanceLogEntry(builder, loggingEvent); + LogEntry logEntry = builder.build(); + + // assert - Trace Id should be recorded as explicit Trace field, not as a label + assertThat(traceId.equalsIgnoreCase(logEntry.getTrace())); + } + + @Test + public void testGetCurrentTraceId() { + // setup + String traceId = "abc"; + TraceLoggingEventEnhancer.setCurrentTraceId(traceId); + + // act + String currentTraceId = TraceLoggingEventEnhancer.getCurrentTraceId(); + + // assert + assertThat(traceId.equalsIgnoreCase(currentTraceId)); + } +}