Support DD_ env var prefix (#137)

Allow environment variables to be prefixed with either `DATADOG_` (old behavior) or `DD_` (new) in order to use the same configuration names as the Datadog Agent. Fixes #135.

Author: Mr0grog

README.md

@@ -50,8 +50,7 @@ There's also a longer [tutorial](https://dbader.org/blog/monitoring-your-nodejs-
 
 ### Datadog API key
 
-Make sure the `DATADOG_API_KEY` environment variable is set to your Datadog
-API key (you can also set it via the `apiKey` option in code). You can find the API key under [Integrations > APIs](https://app.datadoghq.com/account/settings#api). *Please note the API key is different from an **application key**. For more details, see [Datadog’s “API and Application Keys” docs](https://docs.datadoghq.com/account_management/api-app-keys/).*
+Make sure the `DATADOG_API_KEY` or `DD_API_KEY` environment variable is set to your Datadog API key (you can also set it via the `apiKey` option in code). You can find the API key under [Integrations > APIs](https://app.datadoghq.com/account/settings#api). *Please note the API key is different from an **application key**. For more details, see [Datadog’s “API and Application Keys” docs](https://docs.datadoghq.com/account_management/api-app-keys/).*
 
 ### Module setup
 
@@ -121,10 +120,11 @@ Where `options` is an object and can contain the following:
     * Defaults to `datadoghq.com`.
     * See more details on setting your site at:
         https://docs.datadoghq.com/getting_started/site/#access-the-datadog-site
-    * You can also set this via the `DATADOG_SITE` environment variable.
+    * You can also set this via the `DATADOG_SITE` or `DD_SITE` environment variable.
 * `apiKey`: Sets the Datadog API key. (optional)
     * It's usually best to keep this in an environment variable.
-      Datadog-metrics looks for the API key in `DATADOG_API_KEY` by default.
+      Datadog-metrics looks for the API key in the `DATADOG_API_KEY` or
+      `DD_API_KEY` environment variable by default.
     * You must either set this option or the environment variable. An API key
       is required to send metrics.
     * Make sure not to confuse this with your _application_ key! For more
@@ -339,6 +339,8 @@ Contributions are always welcome! For more info on how to contribute or develop
         * The `flush()` method now returns a promise.
         * The `report(series)` method on any custom reporters should now return a promise. For now, datadog-metrics will use the old callback-based behavior if the method signature has callbacks listed after `series` argument.
 
+    * Environment variables can now be prefixed with *either* `DATADOG_` or `DD_` (previously, only `DATADOG_` worked) in order to match configuration with the Datadog agent. For example, you can set your API key via `DATADOG_API_KEY` or `DD_API_KEY`.
+
     **Bug Fixes:**
 
     * Support setting the `site` option via the `DATADOG_SITE` environment variable. The `apiHost` option was renamed to `site` in v0.11.0, but the `DATADOG_API_HOST` environment variable was accidentally left as-is. The old environment variable name is now deprecated, and will be removed at the same time as the `apiHost` option is removed.

lib/reporters.js

@@ -39,11 +39,15 @@ class DatadogReporter {
             }
         }
 
-        apiKey = apiKey || process.env.DATADOG_API_KEY;
-        this.site = site || process.env.DATADOG_SITE || process.env.DATADOG_API_HOST;
+        apiKey = apiKey || process.env.DATADOG_API_KEY || process.env.DD_API_KEY;
+        this.site = site || process.env.DATADOG_SITE || process.env.DD_SITE || process.env.DATADOG_API_HOST;
 
         if (!apiKey) {
-            throw new Error('DATADOG_API_KEY environment variable not set');
+            throw new Error(
+                'Datadog API key not found. You must specify one via a ' +
+                'configuration option or the DATADOG_API_KEY (or DD_API_KEY) ' +
+                'environment variable.'
+            );
         }
 
         const configuration = datadogApiClient.client.createConfiguration({
@@ -104,10 +108,11 @@ class DatadogReporter {
             if (error.code === 403) {
                 throw new AuthorizationError(
                     'Your Datadog API key is not authorized to send ' +
-                    'metrics. Check to make sure the DATADOG_API_KEY ' +
-                    'environment variable or the `apiKey` init option is set ' +
-                    'to a valid API key for your Datadog account, and ' +
-                    'that it is not an *application* key. For more, see: ' +
+                    'metrics. Check to make sure the DATADOG_API_KEY or ' +
+                    'DD_API_KEY environment variable or the `apiKey` init ' +
+                    'option is set to a valid API key for your Datadog ' +
+                    'account, and that it is not an *application* key. ' +
+                    'For more, see: ' +
                     'https://docs.datadoghq.com/account_management/api-app-keys/',
                     { cause: error }
                 );

test/reporters_tests.js

@@ -29,25 +29,27 @@ describe('DatadogReporter', function() {
         let originalEnv = Object.entries(process.env);
 
         afterEach(() => {
-            for (const [key, value] of originalEnv) {
-                process.env[key] = value;
-            }
+            process.env = Object.fromEntries(originalEnv);
         });
 
         it('creates a DatadogReporter', () => {
             const instance = new DatadogReporter('abc', '123', 'datadoghq.eu');
             instance.should.be.an.instanceof(DatadogReporter);
         });
 
-        it('reads the API key from environment if not specified', () => {
+        it('reads the API key from DATADOG_API_KEY environment if not specified', () => {
             process.env.DATADOG_API_KEY = 'abc';
             const instance = new DatadogReporter();
             instance.should.be.an.instanceof(DatadogReporter);
         });
 
-        it('throws if no API key is set', () => {
-            delete process.env.DATADOG_API_KEY;
+        it('reads the API key from DD_API_KEY environment if not specified', () => {
+            process.env.DD_API_KEY = 'abc';
+            const instance = new DatadogReporter();
+            instance.should.be.an.instanceof(DatadogReporter);
+        });
 
+        it('throws if no API key is set', () => {
             (() => new DatadogReporter()).should.throw(/DATADOG_API_KEY/);
         });
     });