@graphql-yoga/plugin-prometheus/esm/index.js

Prometheus plugin for GraphQL Yoga.

import { getOperationAST } from 'graphql';
import { register as defaultRegistry } from 'prom-client';
import { createCounter, createHistogram, createSummary, getCounterFromConfig, getHistogramFromConfig, getSummaryFromConfig, usePrometheus as useEnvelopPrometheus, } from '@envelop/prometheus';
export { createCounter, createHistogram, createSummary, getHistogramFromConfig, getCounterFromConfig, getSummaryFromConfig, };
const DEFAULT_METRICS_CONFIG = {
    graphql_envelop_deprecated_field: true,
    graphql_envelop_request: true,
    graphql_envelop_request_duration: true,
    graphql_envelop_request_time_summary: true,
    graphql_envelop_phase_parse: true,
    graphql_envelop_phase_validate: true,
    graphql_envelop_phase_context: true,
    graphql_envelop_error_result: true,
    graphql_envelop_execute_resolver: false,
    graphql_envelop_phase_execute: true,
    graphql_envelop_phase_subscribe: true,
    graphql_envelop_schema_change: true,
    graphql_yoga_http_duration: true,
};
export function usePrometheus(options) {
    const endpoint = options.endpoint || '/metrics';
    const registry = options.registry || defaultRegistry;
    const resolvedOptions = {
        ...options,
        metrics: {
            ...DEFAULT_METRICS_CONFIG,
            ...options.metrics,
        },
    };
    const basePlugin = {
        onPluginInit({ addPlugin }) {
            addPlugin(useEnvelopPrometheus({ ...resolvedOptions, registry }));
            addPlugin({
                onRequest({ url, fetchAPI, endResponse }) {
                    if (endpoint && url.pathname === endpoint) {
                        return registry.metrics().then(metrics => {
                            endResponse(new fetchAPI.Response(metrics, {
                                headers: {
                                    'Content-Type': registry.contentType,
                                },
                            }));
                        });
                    }
                    return undefined;
                },
            });
        },
    };
    const httpHistogram = getHistogramFromConfig(resolvedOptions, 'graphql_yoga_http_duration', ['request'], {
        help: 'Time spent on HTTP connection',
        labelNames: ['operationName', 'operationType', 'method', 'statusCode', 'url'],
    }, (params, { request, response }) => ({
        method: request.method,
        statusCode: response.status,
        operationType: params.operationType || 'unknown',
        operationName: params.operationName || 'Anonymous',
        url: request.url,
    }));
    // We don't need to register any hooks if the metric is not enabled
    if (!httpHistogram) {
        return basePlugin;
    }
    const startByRequest = new WeakMap();
    const paramsByRequest = new WeakMap();
    return {
        ...basePlugin,
        onRequest({ request }) {
            startByRequest.set(request, Date.now());
        },
        onParse({ context }) {
            // If only it is Yoga, we calculate HTTP request time
            if (context.request) {
                return ({ result: document, context }) => {
                    const operationAST = getOperationAST(document, context.params.operationName);
                    const params = {
                        document,
                        operationName: operationAST?.name?.value,
                        operationType: operationAST?.operation,
                    };
                    paramsByRequest.set(context.request, params);
                };
            }
            return undefined;
        },
        onResponse({ request, response, serverContext }) {
            const start = startByRequest.get(request);
            const params = paramsByRequest.get(request);
            if (start && params) {
                const context = { ...serverContext, request, response };
                const completeParams = { ...params, request, response };
                if (httpHistogram.shouldObserve(completeParams, context)) {
                    httpHistogram.histogram.observe(httpHistogram.fillLabelsFn(completeParams, context), (Date.now() - start) / 1000);
                }
            }
        },
    };
}