Global functions

functions:
  handle_event_global:
    entry_point: HandleEventGlobal
    description: Relays handle_event calls the appropriate install function
    global: true

$ ocp directory list-global-functions ocp_shakedown
https://function.zaius.app/ocp_shakedown/global_fn

import * as App from '@zaiusinc/app-sdk';
import {logger, storage} from '@zaiusinc/app-sdk';

/**
 * Relays an event to a function. The setup here is during the Lifecycle#onInstall
 * hook a record of the external tracker id -> zaius installation id is persisted in
 * the shared key-value store. This information is used by the global function to
 * look up the correct endpoint URL of the function and relay the request to it.
 */
export class HandleEventGlobal extends App.GlobalFunction {
  /**
   * Relay an event to an install fn
   * @returns App.Response as the HTTP response
   */
  public async perform(): Promise<App.Response> {
    // ODP account information is provided in the query string of the hook request
    const trackerId = this.request.params['tracker_id'] as string;
    logger.info(`HandleEventGlobal call for tracker ${trackerId}`);
    if (!trackerId) {
      return new App.Response(400, 'Missing required tracker_id parameter');
    }

    // find the installation id
    const installation = await storage.sharedKvStore.get(trackerId);
    if (!installation) {
      return new App.Response(404, `Install not found for tracker ${trackerId}`);
    }

    return this.relay(installation.installId as number);
  }

  private async relay(installId: number): Promise<App.Response> {
    // get all the hook endpoints for the installation
    const fns = await App.functions.getEndpoints(installId);
    const email = this.request.params['email'] as string;
    logger.info(
            `Relaying hook for install ${installId} to: ${fns.handle_event}?email=${email}`
    );

    // relay the request to the handle_event fn endpoint
    const result = await fetch(`${fns.handle_event}?email=${email}`, {
      method: 'POST',
      body: this.request.body
    });

    // return resulting info in the response
    return new App.Response(result.status, result.body);
  }
}