Add support for W3C traceparent HTTP header

cf-java-logging-support-core/beats/app-logs/docs/fields.asciidoc

@@ -91,6 +91,19 @@ required: False
 A unique identifier that can be used to correlate multiple messages to a request.
 
 
+==== w3c_traceparent
+
+type: string
+
+example: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01
+
+required: False
+
+The content of the W3C traceparent header as defined in 
+https://www.w3.org/TR/trace-context/#traceparent-header.
+The traceparent allows correlation of logs to the request.
+
+
 ==== sap_passport
 
 type: string

cf-java-logging-support-core/beats/app-logs/etc/app-logs.template.json

@@ -198,6 +198,11 @@
           "index": "not_analyzed",
           "type": "string"
         },
+        "w3c_traceparent": {
+          "doc_values": true,
+          "index": "not_analyzed",
+          "type": "string"
+        },
         "written_at": {
           "doc_values": true,
           "ignore_malformed": true,

cf-java-logging-support-core/beats/app-logs/etc/fields.yml

@@ -76,6 +76,15 @@ ctx:
       description: |
         A unique identifier that can be used to correlate multiple messages to a request.
 
+    - name: "w3c_traceparent"
+      type: string
+      required: false
+      example: "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01"
+      description: |
+        The content of the W3C traceparent header as defined in 
+        https://www.w3.org/TR/trace-context/#traceparent-header.
+        The traceparent allows correlation of logs to the request.
+
     - name: "sap_passport"
       type: string
       required: false

cf-java-logging-support-core/beats/request-metrics/docs/fields.asciidoc

@@ -100,6 +100,19 @@ required: False
 A unique identifier that can be used to correlate multiple messages to a request.
 
 
+==== w3c_traceparent
+
+type: string
+
+example: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01
+
+required: False
+
+The content of the W3C traceparent header as defined in 
+https://www.w3.org/TR/trace-context/#traceparent-header.
+The traceparent allows correlation of logs to the request.
+
+
 ==== sap_passport
 
 type: string

cf-java-logging-support-core/beats/request-metrics/etc/fields.yml

@@ -85,6 +85,15 @@ ctx:
       description: |
         A unique identifier that can be used to correlate multiple messages to a request.
 
+    - name: "w3c_traceparent"
+      type: string
+      required: false
+      example: "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01"
+      description: |
+        The content of the W3C traceparent header as defined in 
+        https://www.w3.org/TR/trace-context/#traceparent-header.
+        The traceparent allows correlation of logs to the request.
+
     - name: "sap_passport"
       type: string
       required: false

cf-java-logging-support-core/beats/request-metrics/etc/request-metrics.template.json

@@ -263,6 +263,11 @@
           "index": "not_analyzed",
           "type": "string"
         },
+        "w3c_traceparent": {
+          "doc_values": true,
+          "index": "not_analyzed",
+          "type": "string"
+        },
         "written_at": {
           "doc_values": true,
           "ignore_malformed": true,

cf-java-logging-support-core/src/main/java/com/sap/hcp/cf/logging/common/Fields.java

@@ -13,6 +13,7 @@ public interface Fields {
   public String WRITTEN_TS = "written_ts";
   public String CORRELATION_ID = "correlation_id";
   public String REQUEST_ID = "request_id";
+  public String W3C_TRACEPARENT = "w3c_traceparent";
   public String SAP_PASSPORT = "sap_passport";
   public String SAP_PASSPORT_ACTION = "sap_passport_Action";
   public String SAP_PASSPORT_ACTIONTYPE = "sap_passport_ActionType";

cf-java-logging-support-core/src/main/java/com/sap/hcp/cf/logging/common/request/HttpHeaders.java

@@ -36,6 +36,7 @@ public enum HttpHeaders implements HttpHeader {
                                                X_VCAP_REQUEST_ID("x-vcap-request-id", Fields.REQUEST_ID, true), //
                                                CORRELATION_ID("X-CorrelationID", Fields.CORRELATION_ID, true,
                                                               X_VCAP_REQUEST_ID), //
+                                               W3C_TRACEPARENT("traceparent", Fields.W3C_TRACEPARENT, true),
                                                SAP_PASSPORT("sap-passport", Fields.SAP_PASSPORT, true), //
                                                TENANT_ID("tenantid", Fields.TENANT_ID, true); //
 

cf-java-logging-support-core/src/test/java/com/sap/hcp/cf/logging/common/request/HttpHeadersTest.java

@@ -24,7 +24,7 @@ public void resetLogContext() {
 
     @Test
     public void hasCorrectNumberOfTypes() throws Exception {
-        assertThat(HttpHeaders.values().length, is(equalTo(19)));
+        assertThat(HttpHeaders.values().length, is(equalTo(20)));
     }
 
     @Test
@@ -34,6 +34,7 @@ public void hasCorrectNames() throws Exception {
         assertThat(HttpHeaders.CORRELATION_ID.getName(), is("X-CorrelationID"));
         assertThat(HttpHeaders.REFERER.getName(), is("referer"));
         assertThat(HttpHeaders.TENANT_ID.getName(), is("tenantid"));
+        assertThat(HttpHeaders.W3C_TRACEPARENT.getName(), is("traceparent"));
         assertThat(HttpHeaders.X_CUSTOM_HOST.getName(), is("x-custom-host"));
         assertThat(HttpHeaders.X_FORWARDED_FOR.getName(), is("x-forwarded-for"));
         assertThat(HttpHeaders.X_FORWARDED_HOST.getName(), is("x-forwarded-host"));
@@ -56,6 +57,7 @@ public void hasCorrectFields() throws Exception {
         assertThat(HttpHeaders.CORRELATION_ID.getField(), is(Fields.CORRELATION_ID));
         assertThat(HttpHeaders.REFERER.getField(), is(nullValue()));
         assertThat(HttpHeaders.TENANT_ID.getField(), is(Fields.TENANT_ID));
+        assertThat(HttpHeaders.W3C_TRACEPARENT.getField(), is(Fields.W3C_TRACEPARENT));
         assertThat(HttpHeaders.X_CUSTOM_HOST.getField(), is(Fields.X_CUSTOM_HOST));
         assertThat(HttpHeaders.X_FORWARDED_FOR.getField(), is(Fields.X_FORWARDED_FOR));
         assertThat(HttpHeaders.X_FORWARDED_HOST.getField(), is(Fields.X_FORWARDED_HOST));
@@ -93,6 +95,7 @@ public void hasCorrectAliases() throws Exception {
         assertThat(HttpHeaders.CORRELATION_ID.getAliases(), containsInAnyOrder(HttpHeaders.X_VCAP_REQUEST_ID));
         assertThat(HttpHeaders.REFERER.getAliases(), is(empty()));
         assertThat(HttpHeaders.TENANT_ID.getAliases(), is(empty()));
+        assertThat(HttpHeaders.W3C_TRACEPARENT.getAliases(), is(empty()));
         assertThat(HttpHeaders.X_CUSTOM_HOST.getAliases(), is(empty()));
         assertThat(HttpHeaders.X_FORWARDED_FOR.getAliases(), is(empty()));
         assertThat(HttpHeaders.X_FORWARDED_HOST.getAliases(), is(empty()));
@@ -111,7 +114,8 @@ public void hasCorrectAliases() throws Exception {
     @Test
     public void propagatesCorrectHeaders() throws Exception {
         assertThat(HttpHeaders.propagated(), containsInAnyOrder(HttpHeaders.CORRELATION_ID, HttpHeaders.SAP_PASSPORT,
-                                                                HttpHeaders.TENANT_ID, HttpHeaders.X_VCAP_REQUEST_ID));
+                                                                HttpHeaders.TENANT_ID, HttpHeaders.W3C_TRACEPARENT,
+                                                                HttpHeaders.X_VCAP_REQUEST_ID));
     }
 
 }

cf-java-logging-support-servlet/src/main/java/com/sap/hcp/cf/logging/servlet/filter/CorrelationIdFilter.java

@@ -1,8 +1,11 @@
 package com.sap.hcp.cf.logging.servlet.filter;
 
 import static com.sap.hcp.cf.logging.common.customfields.CustomField.customField;
+import static com.sap.hcp.cf.logging.common.request.HttpHeaders.W3C_TRACEPARENT;
+import static java.util.Optional.ofNullable;
 
 import java.util.UUID;
+import java.util.function.Predicate;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -25,13 +28,19 @@ public class CorrelationIdFilter extends AbstractLoggingFilter {
 
     private static final Logger LOG = LoggerFactory.getLogger(CorrelationIdFilter.class);
     private HttpHeader correlationHeader;
+    private HttpHeader traceparentHeader;
 
     public CorrelationIdFilter() {
         this(HttpHeaders.CORRELATION_ID);
     }
 
     public CorrelationIdFilter(HttpHeader correlationHeader) {
+        this(correlationHeader, W3C_TRACEPARENT);
+    }
+
+    public CorrelationIdFilter(HttpHeader correlationHeader, HttpHeader traceparentHeader) {
         this.correlationHeader = correlationHeader;
+        this.traceparentHeader = traceparentHeader;
     }
 
     @Override
@@ -43,7 +52,10 @@ protected void beforeFilter(HttpServletRequest request, HttpServletResponse resp
 
     private String determineCorrelationId(HttpServletRequest request) {
         String correlationId = HttpHeaderUtilities.getHeaderValue(request, correlationHeader);
-        if (correlationId == null || correlationId.isEmpty() || correlationId.equals(Defaults.UNKNOWN)) {
+        if (isBlankOrDefault(correlationId)) {
+            correlationId = getCorrelationIdFromTraceparent(request);
+        }
+        if (isBlankOrDefault(correlationId)) {
             correlationId = String.valueOf(UUID.randomUUID());
             // add correlation-id as custom field, since it is added to MDC only
             // in the next step
@@ -53,6 +65,25 @@ private String determineCorrelationId(HttpServletRequest request) {
         return correlationId;
     }
 
+    private boolean isBlankOrDefault(String value) {
+        return value == null || value.isEmpty() || value.equals(Defaults.UNKNOWN);
+    }
+
+    private String getCorrelationIdFromTraceparent(HttpServletRequest request) {
+        String traceparent = HttpHeaderUtilities.getHeaderValue(request, traceparentHeader);
+        return ofNullable(traceparent).filter(not(this::isBlankOrDefault)).map(this::parseTraceparent).orElse(
+                                                                                                                        null);
+    }
+
+    private <T> Predicate<T> not(Predicate<T> p) {
+        return p.negate();
+    }
+
+    private String parseTraceparent(String value) {
+        String[] tokens = value.split("-");
+        return tokens.length >= 2 ? tokens[1] : null;
+    }
+
     private void addCorrelationIdHeader(HttpServletResponse response, String correlationId) {
         if (!response.isCommitted() && response.getHeader(correlationHeader.getName()) == null) {
             response.setHeader(correlationHeader.getName(), correlationId);
@@ -63,5 +94,4 @@ private void addCorrelationIdHeader(HttpServletResponse response, String correla
     protected void cleanup(HttpServletRequest request, HttpServletResponse response) {
         LogContext.remove(correlationHeader.getField());
     }
-
 }

cf-java-logging-support-servlet/src/test/java/com/sap/hcp/cf/logging/servlet/filter/CorrelationIdFilterTest.java

@@ -29,7 +29,9 @@
 @RunWith(MockitoJUnitRunner.class)
 public class CorrelationIdFilterTest {
 
-    private static String KNOWN_CORRELATION_ID = UUID.randomUUID().toString();
+    private static final String KNOWN_CORRELATION_ID = UUID.randomUUID().toString();
+    private static final String KNOWN_TRACE_ID = "4bf92f3577b34da6a3ce929d0e0e4736";
+    private static final String KNOWN_TRACEPARENT = "00-" + KNOWN_TRACE_ID + "-00f067aa0ba902b7-01";
 
     @Mock
     private HttpServletRequest request;
@@ -108,13 +110,40 @@ public void doesNotOverwriteCorrelationIdInResponse() throws Exception {
     }
 
     @Test
-    public void usesCustomHeader() throws Exception {
-        HttpHeader myHeader = new HttpTestHeader("my-header", "my-field", null, false);
-        when(request.getHeader("my-header")).thenReturn(KNOWN_CORRELATION_ID);
+    public void usesCustomCorrelationIdHeader() throws Exception {
+        HttpHeader myCorrelationIdHeader = new HttpTestHeader("my-correlationId-header", "my-correlationId-field", null,
+                                                              false);
+        HttpHeader myTraceparentHeader = new HttpTestHeader("my-traceparent-header", "my-traceparent-field", null,
+                                                            false);
+        when(request.getHeader("my-correlationId-header")).thenReturn(KNOWN_CORRELATION_ID);
+        when(request.getHeader("my-traceparent-header")).thenReturn(KNOWN_TRACEPARENT);
+
+        new CorrelationIdFilter(myCorrelationIdHeader, myTraceparentHeader).doFilter(request, response, chain);
+
+        assertThat(mdcExtractor.getField("my-correlationId-field"), is(equalTo(KNOWN_CORRELATION_ID)));
+        verify(response).setHeader("my-correlationId-header", KNOWN_CORRELATION_ID);
+    }
+
+    @Test
+    public void usesCustomTraceparentHeader() throws Exception {
+        HttpHeader myCorrelationIdHeader = new HttpTestHeader("my-correlationId-header", "my-correlationId-field", null,
+                                                              false);
+        HttpHeader myTraceparentHeader = new HttpTestHeader("my-traceparent-header", "my-traceparent-field", null,
+                                                            false);
+        when(request.getHeader("my-traceparent-header")).thenReturn(KNOWN_TRACEPARENT);
 
-        new CorrelationIdFilter(myHeader).doFilter(request, response, chain);
+        new CorrelationIdFilter(myCorrelationIdHeader, myTraceparentHeader).doFilter(request, response, chain);
+
+        assertThat(mdcExtractor.getField("my-correlationId-field"), is(equalTo(KNOWN_TRACE_ID)));
+        verify(response).setHeader("my-correlationId-header", KNOWN_TRACE_ID);
+    }
+
+    @Test
+    public void usesTraceparentIfCorrelationIdHeaderNotPresent() throws Exception {
+        when(request.getHeader(HttpHeaders.W3C_TRACEPARENT.getName())).thenReturn(KNOWN_TRACEPARENT);
+
+        new CorrelationIdFilter().doFilter(request, response, chain);
 
-        assertThat(mdcExtractor.getField("my-field"), is(equalTo(KNOWN_CORRELATION_ID)));
-        verify(response).setHeader("my-header", KNOWN_CORRELATION_ID);
+        assertThat(getExtractedCorrelationId(), is(equalTo(KNOWN_TRACE_ID)));
     }
 }

cf-java-logging-support-servlet/src/test/java/com/sap/hcp/cf/logging/servlet/filter/RequestLogTest.java

@@ -139,6 +139,19 @@ public void logsSapPassportFromRequestHeader() throws Exception {
         }
     }
 
+    @Test
+    public void logsW3cTraceparentFromRequestHeader() throws Exception {
+        String traceparent = "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01";
+        HttpGet get = createRequestWithHeader(HttpHeaders.W3C_TRACEPARENT.getName(), traceparent);
+        try (CloseableHttpResponse response = client.execute(get)) {
+            assertThat("Application log without traceparent.", getRequestMessage(), hasEntry(Fields.W3C_TRACEPARENT,
+                                                                                             traceparent));
+            assertThat("Request log without traceparent.", getRequestLog(), hasEntry(Fields.W3C_TRACEPARENT,
+                                                                                     traceparent));
+        }
+
+    }
+
 	@Test
 	public void writesCorrelationIdFromHeadersAsResponseHeader() throws Exception {
 		String correlationId = UUID.randomUUID().toString();

cf-java-logging-support-servlet/src/test/java/com/sap/hcp/cf/logging/servlet/filter/RequestLoggingFilterTest.java

@@ -47,6 +47,7 @@ public class RequestLoggingFilterTest {
     private static final String REQUEST_ID = "1234-56-7890-xxx";
     private static final String CORRELATION_ID = "xxx-56-7890-xxx";
     private static final String TENANT_ID = "tenant1";
+    private static final String W3C_TRACEPARENT = "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01";
     private static final String REQUEST = "/foobar";
     private static final String QUERY_STRING = "baz=bla";
     private static final String FULL_REQUEST = REQUEST + "?" + QUERY_STRING;
@@ -211,6 +212,14 @@ public void testExplicitCorrelationId() throws IOException, ServletException {
         assertThat(getField(Fields.TENANT_ID), is(nullValue()));
     }
 
+    @Test
+    public void testExplicitW3cTraceparent() throws IOException, ServletException {
+        mockGetHeader(HttpHeaders.W3C_TRACEPARENT, W3C_TRACEPARENT);
+        FilterChain mockFilterChain = mock(FilterChain.class);
+        new RequestLoggingFilter().doFilter(mockReq, mockResp, mockFilterChain);
+        assertThat(getField(Fields.W3C_TRACEPARENT), is(W3C_TRACEPARENT));
+    }
+
     @Test
     public void testExplicitTenantId() throws IOException, ServletException {
         mockGetHeader(HttpHeaders.TENANT_ID, TENANT_ID);