Initial import from local backup (Documents-Playground/pakerpale)

node_modules/express-logging/lib/logging.js

@@ -0,0 +1,115 @@
+/**
+ * @license
+ * Copyright 2015 Telefónica Investigación y Desarrollo, S.A.U
+ *
+ * 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.
+ */
+
+'use strict';
+
+var onHeaders = require('on-headers');
+
+/**
+ * Express middleware to log the request and response.
+ *
+ * @param {Object} logger
+ *    Logger.
+ * @param {Object} opts
+ *    Object with optional arguments including:
+ *      - blacklist: Array of URL paths to be ignored (e.g. paths for static content)
+ *      - policy: Policy to generate the log entry in the logger. Possible values:
+ *          - message. Only message. Params are included into the message.
+ *          - params. Logger receives an object with the params, and the message.
+ * @return {Function(req, res, next)} Express middleware.
+ */
+module.exports = function(logger, opts) {
+
+  var blacklist = opts && opts.blacklist || [];
+  var policy = opts && opts.policy;
+
+  /**
+   * Return the client address from the last IP address in X-Forwarded-For HTTP header. If not possible to
+   * obtain it from X-Forwarded-For header, then return req.ip (however, this value typically is the load
+   * balancer IP address and it does not provide any valuable information).
+   *
+   * @param {Object} req
+   *    Express request
+   * @return {String}
+   *    Client IP address
+   */
+  function getClientIp(req) {
+    var xff = req.get('x-forwarded-for');
+    if (xff) {
+      var ips = xff.split(',').map(function onIp(ip) {
+        return ip.trim();
+      });
+      var ip = ips[ips.length - 1];
+      if (ip) {
+        return ip;
+      }
+    }
+    return req.ip;
+  }
+
+  /**
+   * Check if the request URL starts with any of the blacklist paths.
+   *
+   * @param {String} url
+   *    Request url
+   * @return {Boolean}
+   *    True if the request URL is included in the blacklist.
+   */
+  function isUrlBlackedListed(url) {
+    return blacklist.some(function(blackListUrl) {
+      return url.indexOf(blackListUrl) === 0;
+    });
+  }
+
+  return function loggingMiddleware(req, res, next) {
+    if (!isUrlBlackedListed(req.originalUrl)) {
+      var startTime = Date.now();
+      if (policy === 'params') {
+        var requestParams = {
+          requestClientIp: getClientIp(req),
+          requestMethod: req.method,
+          requestUrl: req.originalUrl
+        };
+        logger.info(requestParams, 'Request: %s %s', req.method, req.originalUrl);
+      } else {
+        logger.info('Request from %s: %s %s', getClientIp(req), req.method, req.originalUrl);
+      }
+
+      onHeaders(res, function onResponse() {
+        var duration = Date.now() - startTime;
+        var location = res.get('location');
+        if (policy === 'params') {
+          var responseParams = {
+            responseStatusCode: res.statusCode,
+            responseDuration: duration,
+            responseLocation: location
+          };
+          logger.info(responseParams, 'Response with status %d', res.statusCode);
+        } else {
+          if (location) {
+            logger.info('Response with status %d in %d ms. Location: %s', res.statusCode, duration, location);
+          } else {
+            logger.info('Response with status %d in %d ms.', res.statusCode, duration);
+          }
+        }
+      });
+    }
+
+    next();
+  };
+
+};