@talks.converse/js-monitoring/lib/logging.js

Express monitoring middleware with Datadog and Prometheus backends, plus conditional logging.

const helper = require('./helper');

/**
 * Checks if an endpoint matches any of the default exclude regex patterns.
 * @param {string} endpoint - The endpoint path to check.
 * @returns {boolean} True if the endpoint is in the default exclude list, false otherwise.
 */
const isDefaultExcluded = (endpoint) => helper.DEFAULT_EXCLUDES.some((re) => re.test(endpoint || ''));

const loggingEndpointsInclude = process.env.LOGGING_ENDPOINTS_INCLUDE
const loggingEndpointsExclude = process.env.LOGGING_ENDPOINTS_EXCLUDE

/**
 * Compiles include and exclude regex rules for logging endpoints from environment variables.
 * @returns {Object} An object containing compiled include and exclude regex arrays.
 */
const buildLoggingEndpointsConfig = () => ({
    include: helper.compileRegexList(loggingEndpointsInclude),
    exclude: helper.compileRegexList(loggingEndpointsExclude),
});

/**
 * Decides whether to log a request based on configured rules, endpoint path, and exclusion lists.
 * If the request passes the rules and is not in the default excludes, logs the message details.
 * @param {Object} message - The request message object.
 * @param {string} [message.endpoint] - The endpoint path of the request.
 * @param {string} [message.method] - The HTTP method of the request.
 * @param {number} [message.statusCode] - The HTTP status code of the response.
 * @param {Object} [message.query] - The query parameters of the request.
 * @param {Object} [message.body] - The body of the request.
 * @param {Object} [message.response] - The response body.
 * @param {number} [message.latencyMs] - The latency in milliseconds.
 */
const loggingRequest = (message = {}) => {
  const endpointPath = message.endpoint || '';

  const loggingEndpointRules = buildLoggingEndpointsConfig();

  // Must pass include/exclude config AND not be in default excludes
  const passesRules = helper.isEndpointProcessed(endpointPath, loggingEndpointRules) && !isDefaultExcluded(endpointPath);

  if (passesRules) {
    console.log(message);
  }
};

module.exports = {
  loggingRequest,
};