97 lines
2.5 KiB
JavaScript
97 lines
2.5 KiB
JavaScript
import {
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register,
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collectDefaultMetrics,
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} from 'prom-client';
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import Logger from '../logger';
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const LOG_PREFIX = '[prom-scrape-agt]';
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class PrometheusScrapeAgent {
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constructor(options) {
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this.metrics = {};
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this.started = false;
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this.path = options.path || '/metrics';
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this.collectDefaultMetrics = options.collectDefaultMetrics || false;
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this.metricsPrefix = options.prefix || '';
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this.collectionTimeout = options.collectionTimeout || 10000;
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this.roleAndInstanceLabels =
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options.role
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? { role: options.role, instanceId: options.instanceId }
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: {};
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}
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async collect(response) {
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try {
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response.writeHead(200, { 'Content-Type': register.contentType });
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const content = await register.metrics();
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response.end(content);
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Logger.debug(`${LOG_PREFIX} Collected prometheus metrics:\n${content}`);
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} catch (error) {
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response.writeHead(500)
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response.end(error.message);
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Logger.error(`${LOG_PREFIX} Collecting prometheus metrics: ${error.message}`);
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}
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}
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start() {
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if (this.collectDefaultMetrics) collectDefaultMetrics({
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prefix: this.metricsPrefix,
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timeout: this.collectionTimeout,
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labels: this.roleAndInstanceLabels,
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});
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WebApp.connectHandlers.use(this.path, (req, res) => {
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return this.collect(res);
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});
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this.started = true;
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};
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injectMetrics(metricsDictionary) {
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this.metrics = { ...this.metrics, ...metricsDictionary }
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}
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increment(metricName, labelsObject) {
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if (!this.started) return;
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const metric = this.metrics[metricName];
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if (metric) {
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labelsObject = { ...labelsObject, ...this.roleAndInstanceLabels };
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metric.inc(labelsObject)
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}
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}
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decrement(metricName, labelsObject) {
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if (!this.started) return;
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const metric = this.metrics[metricName];
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if (metric) {
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labelsObject = { ...labelsObject, ...this.roleAndInstanceLabels };
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metric.dec(labelsObject)
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}
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}
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set(metricName, value, labelsObject) {
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if (!this.started) return;
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const metric = this.metrics[metricName];
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if (metric) {
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labelsObject = { ...labelsObject, ...this.roleAndInstanceLabels };
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metric.set(labelsObject, value)
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}
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}
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observe(metricName, value, labelsObject) {
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if (!this.started) return;
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const metric = this.metrics[metricName];
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if (metric) {
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labelsObject = { ...labelsObject, ...this.roleAndInstanceLabels };
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metric.observe(labelsObject, value)
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}
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}
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}
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export default PrometheusScrapeAgent;
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