transport.ts

/*
 * Unless explicitly stated otherwise all files in this repository are licensed
 * under the Apache License Version 2.0.
 *
 * This product includes software developed at Datadog (https://www.datadoghq.com/).
 * Copyright 2020-2026 Datadog, Inc.
 */

import log from "loglevel";
import { runtimeLookup, RuntimeType } from "./index";
import { LambdaFunction } from "./interfaces";

export const API_KEY_ENV_VAR = "DD_API_KEY";
export const API_KEY_SECRET_ARN_ENV_VAR = "DD_API_KEY_SECRET_ARN";
export const API_KEY_SSM_ARN_ENV_VAR = "DD_API_KEY_SSM_ARN";
export const KMS_API_KEY_ENV_VAR = "DD_KMS_API_KEY";
export const SITE_URL_ENV_VAR = "DD_SITE";
export const FLUSH_METRICS_TO_LOGS_ENV_VAR = "DD_FLUSH_TO_LOG";

export const transportDefaults = {
  site: "datadoghq.com",
  flushMetricsToLogs: true,
  enableDatadogTracing: true,
};

export class Transport {
  flushMetricsToLogs: boolean;
  site: string;
  apiKey?: string;
  apiKeySecretArn?: string;
  apiKeySsmArn?: string;
  apiKmsKey?: string;
  extensionLayerVersion?: number;
  extensionLayerArn?: string;

  constructor(
    flushMetricsToLogs?: boolean,
    site?: string,
    apiKey?: string,
    apiKeySecretArn?: string,
    apiKeySsmArn?: string,
    apiKmsKey?: string,
    extensionLayerVersion?: number,
    extensionLayerArn?: string,
  ) {
    if (flushMetricsToLogs === undefined) {
      log.debug(`No value provided for flushMetricsToLogs, defaulting to ${transportDefaults.flushMetricsToLogs}`);
      this.flushMetricsToLogs = transportDefaults.flushMetricsToLogs;
    } else {
      this.flushMetricsToLogs = flushMetricsToLogs;
    }

    this.extensionLayerVersion = extensionLayerVersion;
    this.extensionLayerArn = extensionLayerArn;
    // If the extension is used, metrics will be submitted via the extension.
    if (this.extensionLayerVersion !== undefined || this.extensionLayerArn !== undefined) {
      const extensionInfo =
        this.extensionLayerArn !== undefined
          ? `ARN ${this.extensionLayerArn}`
          : `version ${this.extensionLayerVersion}`;
      log.debug(`Using extension ${extensionInfo}, metrics will be submitted via the extension`);
      this.flushMetricsToLogs = false;
    }

    if (site === undefined) {
      log.debug(`No value provided for site, defaulting to ${transportDefaults.site}`);
      this.site = transportDefaults.site;
    } else {
      this.site = site;
    }

    this.apiKey = apiKey;
    this.apiKeySecretArn = apiKeySecretArn;
    this.apiKeySsmArn = apiKeySsmArn;
    this.apiKmsKey = apiKmsKey;
  }

  applyEnvVars(lam: LambdaFunction) {
    log.debug(`Setting Datadog transport environment variables...`);
    lam.addEnvironment(FLUSH_METRICS_TO_LOGS_ENV_VAR, this.flushMetricsToLogs.toString());
    if (this.site !== undefined && this.flushMetricsToLogs === false) {
      lam.addEnvironment(SITE_URL_ENV_VAR, this.site);
    }
    if (this.apiKey !== undefined) {
      lam.addEnvironment(API_KEY_ENV_VAR, this.apiKey);
    }
    if (this.apiKeySecretArn !== undefined) {
      const isNode = runtimeLookup[lam.runtime.name] === RuntimeType.NODE;
      const isSendingSynchronousMetrics =
        this.extensionLayerVersion === undefined && this.extensionLayerArn === undefined && !this.flushMetricsToLogs;
      if (isSendingSynchronousMetrics && isNode) {
        throw new Error(
          `\`apiKeySecretArn\` is not supported for Node runtimes when using Synchronous Metrics. Use either \`apiKey\` or \`apiKmsKey\`.`,
        );
      }
      lam.addEnvironment(API_KEY_SECRET_ARN_ENV_VAR, this.apiKeySecretArn);
    }
    if (this.apiKeySsmArn !== undefined) {
      lam.addEnvironment(API_KEY_SSM_ARN_ENV_VAR, this.apiKeySsmArn);
    }
    if (this.apiKmsKey !== undefined) {
      lam.addEnvironment(KMS_API_KEY_ENV_VAR, this.apiKmsKey);
    }
  }
}