Drop the official Datadog client (#144)

This drops our dependency on `@datadog/datadog-api-client` in favor of directly calling the API via HTTP. It requires a little more code on our side, but gets us a bit more flexibility and drops a 15 MB (!) dependency that we barely use.

This partly covers #132. There is definitely followup work to do here, but we want to get this out the door so people can use it and provide feedback.

Author: Mr0grog

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
       matrix:
         # Test supported release Node.js versions (even numbers) plus current
         # development version.
-        node_version: [12, 14, 16, 18, 20, 22, 23]
+        node_version: [14, 16, 18, 20, 22, 24]
 
     steps:
       - uses: actions/checkout@v4

CONTRIBUTING.md

@@ -30,7 +30,7 @@ For changes to this repo, follow the [local development](#local-development) ste
 
 1. If you don't have commit rights to this repo, [fork it][fork].
 
-2. Install Node.js 12 or newer.
+2. Install Node.js 14 or newer.
 
 3. Clone your fork (or this repo if you have commit rights) to your local development machine:
 

README.md

@@ -11,7 +11,7 @@ The downside of using the HTTP API is that it can negatively affect your app's p
 
 ## Installation
 
-Datadog-metrics is compatible with Node.js v12 and later. You can install it with NPM:
+Datadog-metrics is compatible with Node.js v14 and later. You can install it with NPM:
 
 ```sh
 npm install datadog-metrics --save
@@ -371,7 +371,9 @@ Contributions are always welcome! For more info on how to contribute or develop
 
 **Breaking Changes:**
 
-TBD
+* The minimum required Node.js version is now v14.0.0.
+
+* The `code` property on `AuthorizationError` instances has been changed to `DATADOG_METRICS_AUTHORIZATION_ERROR` to make names more clear and consistent (it was previously `DATADOG_AUTHORIZATION_ERROR`). If you are using `errorInstance.code` to check types, make sure to update the string you are looking for.
 
 **New Features:**
 
@@ -387,7 +389,7 @@ TBD
 
 **Maintenance:**
 
-TBD
+* Under the hood, we’ve removed a dependency on the official Datadog client (`@datadog/datadog-api-client`). This is an attempt to streamline the package, since the official client comes at a sizeable 15 MB of code for you to download and then load in your application. (#144)
 
 [View diff](https://github.com/dbader/node-datadog-metrics/compare/v0.12.1...main)
 

lib/errors.js

@@ -1,27 +1,66 @@
 'use strict';
 
+/**
+ * Base class for errors from datadog-metrics.
+ * @property {'DATADOG_METRICS_ERROR'} code
+ */
+class DatadogMetricsError extends Error {
+    constructor(message, options = {}) {
+        // @ts-expect-error the ECMAScript version we target with TypeScript
+        // does not include `error.cause` (new in ES 2022), but all versions of
+        // Node.js we support do.
+        super(message, { cause: options.cause });
+        this.code = 'DATADOG_METRICS_ERROR';
+    }
+}
+
+/**
+ * Represents an HTTP error response from the Datadog API.
+ *
+ * @property {'DATADOG_METRICS_HTTP_ERROR'} code
+ * @property {number} status The HTTP status code.
+ */
+class HttpError extends DatadogMetricsError {
+    /**
+     * Create a `HttpError`.
+     * @param {string} message
+     * @param {object} options
+     * @param {any} options.response
+     * @param {any} [options.body]
+     * @param {Error} [options.cause]
+     */
+    constructor (message, options) {
+        super(message, { cause: options.cause });
+        this.code = 'DATADOG_METRICS_HTTP_ERROR';
+        this.response = options.response;
+        this.body = options.body;
+        this.status = this.response.status;
+    }
+}
+
 /**
  * Represents an authorization failure response from the Datadog API, usually
  * because of an invalid API key.
  *
- * @property {'DATADOG_AUTHORIZATION_ERROR'} code
+ * @property {'DATADOG_METRICS_AUTHORIZATION_ERROR'} code
  * @property {number} status
  */
-class AuthorizationError extends Error {
+class AuthorizationError extends DatadogMetricsError {
     /**
      * Create an `AuthorizationError`.
      * @param {string} message
      * @param {object} [options]
      * @param {Error} [options.cause]
      */
     constructor(message, options = {}) {
-        // @ts-expect-error the ECMAScript version we target with TypeScript
-        // does not include `error.cause` (new in ES 2022), but all versions of
-        // Node.js we support do.
         super(message, { cause: options.cause });
-        this.code = 'DATADOG_AUTHORIZATION_ERROR';
+        this.code = 'DATADOG_METRICS_AUTHORIZATION_ERROR';
         this.status = 403;
     }
 }
 
-module.exports = { AuthorizationError };
+module.exports = {
+    DatadogMetricsError,
+    HttpError,
+    AuthorizationError
+};

lib/reporters.js

@@ -1,6 +1,6 @@
 'use strict';
-const datadogApiClient = require('@datadog/datadog-api-client');
-const { AuthorizationError } = require('./errors');
+const { fetch } = require('cross-fetch');
+const { AuthorizationError, DatadogMetricsError, HttpError } = require('./errors');
 const { logDebug, logDeprecation } = require('./logging');
 
 const RETRYABLE_ERROR_CODES = new Set([
@@ -27,39 +27,49 @@ class NullReporter {
 
 /**
  * @private
- * A custom HTTP implementation for Datadog that retries failed requests.
- * Datadog has retries built in, but they don't handle network errors (just
- * HTTP errors), and we want to retry in both cases. This inherits from the
- * built-in HTTP library since we want to use the same fetch implementation
- * Datadog uses instead of adding another dependency.
+ * Manages HTTP requests and associated retry/error handling logic.
  */
-class RetryHttp extends datadogApiClient.client.IsomorphicFetchHttpLibrary {
-    constructor(options = {}) {
-        super(options);
-
-        // HACK: ensure enableRetry is always `false` so the base class logic
-        // does not actually retry (since we manage retries here).
-        Object.defineProperty(this, 'enableRetry', {
-            get () { return false; },
-            set () {},
-        });
+class HttpApi {
+    constructor(options) {
+        this.maxRetries = options.maxRetries;
+        this.backoffBase = options.backoffBase;
+        this.backoffMultiplier = 2;
     }
 
-    async send(request) {
+    async send(url, options) {
         let i = 0;
         while (true) {  // eslint-disable-line no-constant-condition
-            let response, error;
+            let response, body, error;
             try {
-                response = await super.send(request);
+                logDebug(`Sending HTTP request to "${url}"`);
+                response = await fetch(url, options);
+                body = await response.json();
             } catch (e) {
                 error = e;
             }
 
+            const details = this.getLogDetails(url, response, error);
             if (this.isRetryable(response || error, i)) {
-                await sleep(this.retryDelay(response || error, i));
+                const delay = this.retryDelay(response || error, i);
+                logDebug(`HTTP request failed, retrying in ${delay} ms. ${details}`);
+
+                await sleep(delay);
             } else if (response) {
-                return response;
+                if (response.status >= 400) {
+                    logDebug(`HTTP request failed. ${details}`);
+
+                    let message = `Could not fetch ${url}`;
+                    if (body && body.errors) {
+                        message += ` (${body.errors.join(', ')})`;
+                    }
+                    throw new HttpError(message, { response });
+                }
+
+                logDebug(`HTTP request succeeded. ${details}`);
+                return body;
             } else {
+                logDebug(`HTTP request failed. ${details}`);
+
                 throw error;
             }
 
@@ -75,8 +85,8 @@ class RetryHttp extends datadogApiClient.client.IsomorphicFetchHttpLibrary {
     isRetryable(response, tryCount) {
         return tryCount < this.maxRetries && (
             RETRYABLE_ERROR_CODES.has(response.code)
-            || response.httpStatusCode === 429
-            || response.httpStatusCode >= 500
+            || response.status === 429
+            || response.status >= 500
         );
     }
 
@@ -87,16 +97,16 @@ class RetryHttp extends datadogApiClient.client.IsomorphicFetchHttpLibrary {
      * @returns {number}
      */
     retryDelay(response, tryCount) {
-        if (response.httpStatusCode === 429) {
+        if (response.status === 429) {
             // Datadog's official client supports just the 'x-ratelimit-reset'
             // header, so we support that here in addition to the standardized
             // 'retry-after' heaer.
             // There is also an upcoming IETF standard for 'ratelimit', but it
             // has moved away from the syntax used in 'x-ratelimit-reset'. This
             // stuff might change in the future.
             // https://datatracker.ietf.org/doc/draft-ietf-httpapi-ratelimit-headers/
-            const delayHeader = response.headers['retry-after']
-                || response.headers['x-ratelimit-reset'];
+            const delayHeader = response.headers.get('retry-after')
+                || response.headers.get('x-ratelimit-reset');
             const delayValue = parseInt(delayHeader, 10);
             if (!isNaN(delayValue) && delayValue > 0) {
                 return delayValue * 1000;
@@ -105,6 +115,17 @@ class RetryHttp extends datadogApiClient.client.IsomorphicFetchHttpLibrary {
 
         return this.backoffMultiplier ** tryCount * this.backoffBase * 1000;
     }
+
+    /**
+     * @private
+     * @param {string} url
+     * @param {Response?} response
+     * @param {Error?} error
+     */
+    getLogDetails(url, response, error) {
+        let result = response ? `HTTP status: ${response.status}` : `error: ${error}`;
+        return `URL: "${url}", ${result}`;
+    }
 }
 
 /**
@@ -117,8 +138,8 @@ class RetryHttp extends datadogApiClient.client.IsomorphicFetchHttpLibrary {
  *           wait this long multiplied by 2^(retry count).
  */
 
-/** @type {WeakMap<DatadogReporter, datadogApiClient.v1.MetricsApi>} */
-const datadogClients = new WeakMap();
+/** @type {WeakMap<DatadogReporter, string>} */
+const datadogApiKeys = new WeakMap();
 
 /**
  * Create a reporter that sends metrics to Datadog's API.
@@ -142,43 +163,34 @@ class DatadogReporter {
         }
 
         const apiKey = options.apiKey || process.env.DATADOG_API_KEY || process.env.DD_API_KEY;
-        this.site = options.site
-            || process.env.DATADOG_SITE
-            || process.env.DD_SITE
-            || process.env.DATADOG_API_HOST;
 
         if (!apiKey) {
-            throw new Error(
+            throw new DatadogMetricsError(
                 'Datadog API key not found. You must specify one via the ' +
                 '`apiKey` configuration option or the DATADOG_API_KEY or ' +
                 'DD_API_KEY environment variable.'
             );
         }
 
-        const configuration = datadogApiClient.client.createConfiguration({
-            authMethods: {
-                apiKeyAuth: apiKey,
-            },
-            httpApi: new RetryHttp(),
+        /** @private @type {HttpApi} */
+        this.httpApi = new HttpApi({
             maxRetries: options.retries >= 0 ? options.retries : 2,
+            retryBackoff: options.retryBackoff >= 0 ? options.retryBackoff : 1
         });
 
-        // HACK: Specify backoff here rather than in configration options to
-        // support values less than 2 (mainly for faster tests).
-        const backoff = options.retryBackoff >= 0 ? options.retryBackoff : 1;
-        configuration.httpApi.backoffBase = backoff;
-
-        if (this.site) {
-            // Strip leading `app.` from the site in case someone copy/pasted the
-            // URL from their web browser. More details on correct configuration:
-            // https://docs.datadoghq.com/getting_started/site/#access-the-datadog-site
-            this.site = this.site.replace(/^app\./i, '');
-            configuration.setServerVariables({
-                site: this.site
-            });
-        }
+        /** @private @type {string} */
+        this.site = options.site
+            || process.env.DATADOG_SITE
+            || process.env.DD_SITE
+            || process.env.DATADOG_API_HOST
+            || 'datadoghq.com';
 
-        datadogClients.set(this, new datadogApiClient.v1.MetricsApi(configuration));
+        // Strip leading `app.` from the site in case someone copy/pasted the
+        // URL from their web browser. More details on correct configuration:
+        // https://docs.datadoghq.com/getting_started/site/#access-the-datadog-site
+        this.site = this.site.replace(/^app\./i, '');
+
+        datadogApiKeys.set(this, apiKey);
     }
 
     /**
@@ -201,25 +213,19 @@ class DatadogReporter {
             }
         }
 
-        const metricsApi = datadogClients.get(this);
-
         let submissions = [];
         if (metrics.length) {
-            submissions.push(metricsApi.submitMetrics({
-                body: { series: metrics }
-            }));
+            submissions.push(this.sendMetrics(metrics));
         }
         if (distributions.length) {
-            submissions.push(metricsApi.submitDistributionPoints({
-                body: { series: distributions }
-            }));
+            submissions.push(this.sendDistributions(distributions));
         }
 
         try {
             await Promise.all(submissions);
             logDebug('sent metrics successfully');
         } catch (error) {
-            if (error.code === 403) {
+            if (error.status === 403) {
                 throw new AuthorizationError(
                     'Your Datadog API key is not authorized to send ' +
                     'metrics. Check to make sure the DATADOG_API_KEY or ' +
@@ -235,6 +241,45 @@ class DatadogReporter {
             throw error;
         }
     }
+
+    /**
+     * Send an array of metrics to the Datadog API.
+     * @private
+     * @param {any[]} series
+     * @returns {Promise}
+     */
+    sendMetrics(series) {
+        return this.sendHttp('/v1/series', { body: { series } });
+    }
+
+    /**
+     * Send an array of distributions to the Datadog API.
+     * @private
+     * @param {any[]} series
+     * @returns {Promise}
+     */
+    sendDistributions(series) {
+        return this.sendHttp('/v1/distribution_points', { body: { series } });
+    }
+
+    /**
+     * @private
+     * @param {string} path
+     * @param {any} options
+     * @returns {Promise}
+     */
+    async sendHttp(path, options) {
+        const url = `https://api.${this.site}/api${path}`;
+        const fetchOptions = {
+            method: 'POST',
+            headers: {
+                'DD-API-KEY': datadogApiKeys.get(this),
+                'Content-Type': 'application/json'
+            },
+            body: JSON.stringify(options.body)
+        };
+        return await this.httpApi.send(url, fetchOptions);
+    }
 }
 
 /**