Added optional X-Request-Id to RemoteIpFilter

java/org/apache/catalina/filters/RemoteIpFilter.java

@@ -107,6 +107,14 @@
  * <td>x-forwarded-for</td>
  * </tr>
  * <tr>
+ * <td>requestIdHeader</td>
+ * <td>Name of the Http Header read by this servlet filter that holds a request ID passed by a proxy or the requesting
+ * client</td>
+ * <td>RequestIdHeader</td>
+ * <td>Compliant http header name</td>
+ * <td>x-request-id</td>
+ * </tr>
+ * <tr>
  * <td>internalProxies</td>
  * <td>Regular expression that matches the IP addresses of internal proxies. If they appear in the
  * <code>remoteIpHeader</code> value, they will be trusted and will not appear in the <code>proxiesHeader</code>
@@ -210,6 +218,10 @@
  *       &lt;param-name&gt;protocolHeader&lt;/param-name&gt;
  *       &lt;param-value&gt;x-forwarded-proto&lt;/param-value&gt;
  *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       &lt;param-name&gt;requestIdHeader&lt;/param-name&gt;
+ *       &lt;param-value&gt;x-request-id&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
  * &lt;/filter&gt;
  *
  * &lt;filter-mapping&gt;
@@ -476,6 +488,8 @@ public static class XForwardedRequest extends HttpServletRequestWrapper {
 
         protected int serverPort;
 
+        protected String requestId;
+
         public XForwardedRequest(HttpServletRequest request) {
             super(request);
             this.localName = request.getLocalName();
@@ -568,6 +582,15 @@ public String getRemoteHost() {
             return this.remoteHost;
         }
 
+        @Override
+        public String getRequestId() {
+            if (this.requestId != null) {
+                return this.requestId;
+            }
+
+            return super.getRequest().getRequestId();
+        }
+
         @Override
         public String getScheme() {
             return scheme;
@@ -617,6 +640,10 @@ public void setRemoteHost(String remoteHost) {
             this.remoteHost = remoteHost;
         }
 
+        public void setRequestId(String requestId) {
+            this.requestId = requestId;
+        }
+
         public void setScheme(String scheme) {
             this.scheme = scheme;
         }
@@ -667,6 +694,8 @@ public StringBuffer getRequestURL() {
 
     protected static final String REMOTE_IP_HEADER_PARAMETER = "remoteIpHeader";
 
+    protected static final String REQUEST_ID_HEADER_PARAMETER = "requestIdHeader";
+
     protected static final String TRUSTED_PROXIES_PARAMETER = "trustedProxies";
 
     protected static final String ENABLE_LOOKUPS_PARAMETER = "enableLookups";
@@ -717,6 +746,11 @@ public StringBuffer getRequestURL() {
      */
     private String remoteIpHeader = "X-Forwarded-For";
 
+    /**
+     * @see #setRequestIdHeader(String)
+     */
+    private String requestIdHeader = "";
+
     /**
      * @see #setRequestAttributesEnabled(boolean)
      */
@@ -843,6 +877,14 @@ public void doFilter(HttpServletRequest request, HttpServletResponse response, F
                     }
                 }
             }
+
+            if (!requestIdHeader.isEmpty()) {
+                String requestIdHeaderValue = request.getHeader(requestIdHeader);
+                if (requestIdHeaderValue != null) {
+                    xRequest.setRequestId(requestIdHeaderValue);
+                }
+            }
+
             request.setAttribute(Globals.REQUEST_FORWARDED_ATTRIBUTE, Boolean.TRUE);
 
             if (log.isTraceEnabled()) {
@@ -1016,6 +1058,10 @@ public void init() throws ServletException {
             setRemoteIpHeader(getInitParameter(REMOTE_IP_HEADER_PARAMETER));
         }
 
+        if (getInitParameter(REQUEST_ID_HEADER_PARAMETER) != null) {
+            setRequestIdHeader(getInitParameter(REQUEST_ID_HEADER_PARAMETER));
+        }
+
         if (getInitParameter(TRUSTED_PROXIES_PARAMETER) != null) {
             setTrustedProxies(getInitParameter(TRUSTED_PROXIES_PARAMETER));
         }
@@ -1221,6 +1267,17 @@ public void setRemoteIpHeader(String remoteIpHeader) {
         this.remoteIpHeader = remoteIpHeader;
     }
 
+    /**
+     * <p>Name of the http header from which the request id is extracted.</p>
+     *
+     * <p>Request id propagation is disabled by default. Set a value, e.g. <code>X-Request-Id</code>, to enable it.</p>
+     *
+     * @param requestIdHeader The header name
+     */
+    public void setRequestIdHeader(String requestIdHeader) {
+        this.requestIdHeader = requestIdHeader;
+    }
+
     /**
      * Should this filter set request attributes for IP address, Hostname, protocol and port used for the request? This
      * are typically used in conjunction with an {@link AccessLog} which will otherwise log the original values. Default

webapps/docs/config/filter.xml

@@ -1445,6 +1445,10 @@ FINE: Request "/docs/config/manager.html" with response status "200"
          <param-name>protocolHeader</param-name>
          <param-value>x-forwarded-proto</param-value>
        </init-param>
+       <init-param>
+         <param-name>requestIdHeader</param-name>
+         <param-value>x-request-id</param-value>
+       </init-param>
      </filter>]]></source>
     <p>Request values:</p>
     <table class="defaultTable">
@@ -1685,6 +1689,13 @@ FINE: Request "/docs/config/manager.html" with response status "200"
         specified, the default of <code>x-forwarded-for</code> is used.</p>
       </attribute>
 
+      <attribute name="requestIdHeader" required="false">
+        <p>Name of the HTTP Header read by this valve that holds request ID
+        if passed by the Proxy server or requesting client. Request ID propagation
+        is disabled by default, but can be enabled by setting this attribute,
+        e.g. to <code>x-request-id</code>.</p>
+      </attribute>
+
       <attribute name="internalProxies" required="false">
         <p>Regular expression (using <code>java.util.regex</code>) that a
         proxy&apos;s IP address must match to be considered an internal proxy.