solarwinds-apm/dist/sampling/http.js

OpenTelemetry-based SolarWinds APM library

/*
Copyright 2023-2026 SolarWinds Worldwide, LLC.

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.
*/
import { context, diag } from "@opentelemetry/api";
import { suppressTracing, TimeoutError } from "@opentelemetry/core";
import { unref } from "@solarwinds-apm/module";
import { environment, IS_NODE } from "../env.js";
import { agentFactory } from "../exporters/proxy.js";
import { componentLogger } from "../shared/logger.js";
import { VERSION } from "../version.js";
import { Sampler } from "./sampler.js";
const REQUEST_INTERVAL = 60 * 1000; // 1m
const REQUEST_TIMEOUT = 10 * 1000; // 10s
const USER_AGENT = `solarwinds/apm-js/${VERSION}`;
/** Retrieves the hostname (or User-Agent in browsers) in URL encoded format */
export async function hostname() {
    if (IS_NODE) {
        const { hostname } = await import("node:os");
        return encodeURIComponent(hostname());
    }
    else {
        return encodeURIComponent(navigator.userAgent);
    }
}
/** Retrieves the HTTP getter function to use */
export async function getter(config, logger = diag) {
    if (IS_NODE) {
        const agent = await agentFactory(config)(config.collector.protocol);
        return async function get(url, options) {
            const { get } = url.protocol === "http:"
                ? await import("node:http")
                : await import("node:https");
            return await new Promise((resolve, reject) => {
                const request = get(url, { agent, ...options }, (response) => {
                    logger.debug(`received sampling settings response`, response);
                    let data = Buffer.alloc(0);
                    response
                        .on("error", reject)
                        .on("data", (chunk) => {
                        data = Buffer.concat([data, chunk]);
                    })
                        .on("end", () => {
                        try {
                            const json = JSON.parse(data.toString("utf-8"));
                            resolve(json);
                        }
                        catch (error) {
                            /* eslint-disable-next-line @typescript-eslint/no-unnecessary-type-assertion --
                             * removing the cast makes it complain about passing unknown to reject */
                            reject(error);
                        }
                    });
                });
                request
                    .on("error", reject)
                    .on("timeout", () => request.destroy(new TimeoutError()))
                    .end();
            });
        };
    }
    else {
        return async function get(url, options) {
            const response = await fetch(url, options);
            logger.debug(`received sampling settings response`, response);
            const json = await response.json();
            return json;
        };
    }
}
export class HttpSampler extends Sampler {
    #url;
    #headers;
    #service;
    #hostname = hostname();
    #get;
    #lastWarningMessage = undefined;
    constructor(config, initial) {
        super(config, componentLogger(HttpSampler), initial);
        this.#url = config.collector;
        this.#service = encodeURIComponent(config.service);
        this.#headers = { "User-Agent": USER_AGENT, ...config.headers };
        if (this.#url.hostname.endsWith(".solarwinds.com") || environment.DEV) {
            this.#headers.authorization = `Bearer ${config.token}`;
        }
        this.#get = getter(config, this.logger);
        setTimeout(() => {
            this.#loop().catch(this.#catch.bind(this));
        }, 0);
        unref(setInterval(() => {
            this.#loop().catch(this.#catch.bind(this));
        }, REQUEST_INTERVAL));
    }
    toString() {
        return `HTTP Sampler (${this.#url.host})`;
    }
    /** Logs a de-duplicated warning */
    #warn(message, ...args) {
        if (message !== this.#lastWarningMessage) {
            this.logger.warn(message, ...args);
            this.#lastWarningMessage = message;
        }
        else {
            this.logger.debug(message, ...args);
        }
    }
    /** Resets last memorised warning */
    #reset() {
        this.#lastWarningMessage = undefined;
    }
    /** Settings update loop */
    async #loop() {
        const url = new URL(`./v1/settings/${this.#service}/${await this.#hostname}`, this.#url);
        this.logger.debug(`retrieving sampling settings from ${url.href}`);
        const abort = new AbortController();
        const cancel = setTimeout(() => {
            abort.abort("HTTP request timeout");
        }, REQUEST_TIMEOUT);
        const unparsed = await context.bind(suppressTracing(context.active()), await this.#get)(url, {
            headers: this.#headers,
            signal: abort.signal,
        });
        clearTimeout(cancel);
        const parsed = this.updateSettings(unparsed);
        if (parsed) {
            this.#reset();
        }
        else {
            this.#warn("Retrieved sampling settings are invalid.");
        }
    }
    /** Error catcher */
    #catch(error) {
        let message = "Failed to retrieve sampling settings";
        if (error instanceof Error) {
            message += ` (${error.message})`;
        }
        message += ", tracing will be disabled until valid ones are available.";
        this.#warn(message, error);
    }
}
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