Windshaft-cartodb/lib/api/middlewares/pubsub-metrics.js

75 lines
1.7 KiB
JavaScript

'use strict';
const EVENT_VERSION = '1';
const MAX_LENGTH = 100;
function pubSubMetrics (pubSubMetricsBackend) {
if (!pubSubMetricsBackend.isEnabled()) {
return function pubSubMetricsDisabledMiddleware (req, res, next) { next(); };
}
return function pubSubMetricsMiddleware (req, res, next) {
const data = getEventData(req, res);
if (data.event) {
pubSubMetricsBackend.sendEvent(data.event, data.attributes);
}
return next();
};
}
function getEventData (req, res) {
const event = normalizedField(req.get('Carto-Event'));
const eventSource = normalizedField(req.get('Carto-Event-Source'));
const eventGroupId = normalizedField(req.get('Carto-Event-Group-Id'));
if (!event || !eventSource) {
return { event: undefined, attributes: undefined };
}
const attributes = {
event_source: eventSource,
user_id: res.locals.userId,
response_code: res.statusCode.toString(),
source_domain: req.hostname,
event_time: new Date().toISOString(),
event_version: EVENT_VERSION
};
if (eventGroupId) {
attributes.event_group_id = eventGroupId;
}
const responseTime = getResponseTime(res);
if (responseTime) {
attributes.response_time = responseTime.toString();
}
return { event, attributes };
}
function normalizedField (field) {
if (!field) {
return undefined;
}
return field.toString().trim().substr(0, MAX_LENGTH);
}
function getResponseTime (res) {
const profiler = res.get('X-Tiler-Profiler');
let stats;
try {
stats = JSON.parse(profiler);
} catch (e) {
return undefined;
}
return stats.total;
}
module.exports = pubSubMetrics;