Webhook (express serverless function) stable local but inconsistent in production, possibly async/await issue?

I have am working on a webhook (site: optimonkwebhook.netlify.app) that parses the incoming data (URL Encoded) into a payload (XML) to be posted to an API endpoint. Locally sending the payload via postman this function runs as expected every time. It receives the data, parses data, receives access token then posts the payload. However, in Netlify production when posting via postman the data is received, parses data but fails to consistently receive the access token. If I post 3+ times back to back it seems to work. I am thinking maybe there is something wrong with my await axios posts? I have tried switching it to a background function to allow for more runtime but this didn’t change the issue.

For what it’s worth I started this project off this repo netlify-express/express/server.js at 0780127cd575704e2a2a00a1a648ba5a5a66c388 · neverendingqs/netlify-express · GitHub

Ask Netlify is sweet btw, but no avail in solving this. Last but maybe not least I am receiving this error:
“ERROR (node:16) [DEP0066] DeprecationWarning: OutgoingMessage.prototype._headers is deprecated
(Use node --trace-deprecation ... to show where the warning was created)”
Which this is also inconsistent as the first post receives this error but post after that do not so I am not sure if it’s associated. This error also only appears in Prod. I’ve attempted to set my node version to 10.11.0 in the environment variables as suggested by some stack overflow articles, however, this isn’t resolving the issue.

I am still fairly new working with Async Functions/Express/Axios so I appreciate any patience and understanding. I do have other functions working properly so I am stumped as to why this one is not. I am truly grateful for any support on this.

Here is my server function code which is the problematic piece:

'use strict';
const express = require('express');
const serverless = require('serverless-http');
const app = express();
const bodyParser = require('body-parser');
const axios = require("axios").default;

const router = express.Router();
router.get('/', (req, res) => {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.write('Optimonk -> Acoustic Webhook is live ');

// Set authentication variables in Netlify's environment
const acousticClientID = process.env.acousticClientID;
const acousticClientSecret = process.env.acousticClientSecret;
const acousticRefreshToken = process.env.acousticRefreshToken;
const acousticAPIURL = process.env.ACOUSTIC_WEBHOOK_URL;
const acousticTokenURL = process.env.ACOUSTIC_TOKEN_URL;

/* setting headers to get access token from Acoustic */
var configAccessToken = {
  headers: { 'Content-Type': 'application/x-www-form-urlencoded' }

const acousticAccessTokenParams = new URLSearchParams({
  "grant_type": "refresh_token",
  "client_id": acousticClientID,
  "client_secret": acousticClientSecret,
  "refresh_token": acousticRefreshToken

// will not have front end so don't need to render different routes
//router.get('/another', (req, res) => res.json({ route: req.originalUrl }));

// To display the post body as a response - will not have front end so don't need to render different routes
//router.post('/', (req, res) => res.json({ postBody: req.body }));

// create application/x-www-form-urlencoded parser
var urlencodedParser = bodyParser.urlencoded({ extended: true })

// POST /login gets urlencoded bodies
router.post('/', urlencodedParser, function(req, res) {
    // start grabbing values from post
    var email = req.body.email;
    var firstname = req.body.firstname;
    var lastname = req.body.lastname;
    var zipcode = req.body.zipcode;
    var campaign_name = req.body.campaign_name;
    var property = req.body.property;

    console.info("First Name:", firstname);
    console.info("Last Name:", lastname);
    console.info("Email:", email);
    console.info("Zip:", zipcode);
    console.info("Campaign Name:", campaign_name);
    console.info("Property:", property);
    // end grabbing values from post
    // send response with payload values back to requestor
    res.send('welcome, ' + req.body.firstname + ' ' + req.body.lastname + ' ' + req.body.zipcode + ' ' + req.body.email + ' ' + req.body.campaign_name + ' ' + req.body.property);
    // start removing undefined values
    var lead_source = "";
    var Email_AV_OptIn = "";
    var Email_GAH_OptIn = "";
    var Email_LAFLAG_OptIn = "";
    var Email_LASLC_OptIn = "";
    var Email_SB_OptIn = "";
    var Email_SV_OptIn = "";
    var Email_WGT_OptIn = "";
    if (Email_AV_OptIn === '' || Email_AV_OptIn === null) {
        var Email_AV_OptIn = "";
    } else if (Email_GAH_OptIn === '' || Email_GAH_OptIn === null) {
        var Email_GAH_OptIn = "";
    } else if (Email_LAFLAG_OptIn === '' || Email_LAFLAG_OptIn === null) {
        var Email_LAFLAG_OptIn = "";
    } else if (Email_LASLC_OptIn === '' || Email_LASLC_OptIn === null) {
        var Email_LASLC_OptIn = "";
    } else if (Email_SB_OptIn === '' || Email_SB_OptIn === null) {
        var Email_SB_OptIn = "";
    } else if (Email_SV_OptIn === '' || Email_SV_OptIn === null) {
        var Email_SV_OptIn = "";
    } else if (Email_WGT_OptIn === '' || Email_WGT_OptIn === null) {
        var Email_WGT_OptIn = "";
    // end removing undefined values
    // start setting property specific values for lead source and opt-ins
    if (property === "AV") {
        var Email_AV_OptIn = "Yes";
        var lead_source = "AV Popup to Lead";
        var property_optin_block = `<COLUMN>
    } else if (property === "GAH") {
        var Email_GAH_OptIn = "Yes";
        var lead_source = "GAH Popup to Lead";
        var property_optin_block = `<COLUMN>
    } else if (property === "LAFLAG") {
        var Email_LAFLAG_OptIn = "Yes";
        var lead_source = "LAFLAG Popup to Lead";
        var property_optin_block = `<COLUMN>
    } else if (property === "LASLC") {
        var Email_LASLC_OptIn = "Yes";
        var lead_source = "LASLC Popup to Lead";
        var property_optin_block = `<COLUMN>
    } else if (property === "SB") {
        var Email_SB_OptIn = "Yes";
        var lead_source = "SB Popup to Lead";
        var property_optin_block = `<COLUMN>
    } else if (property === "SV") {
        var Email_SV_OptIn = "Yes";
        var lead_source = "SV Popup to Lead";
        var property_optin_block = `<COLUMN>
    } else if (property === "WG") {
        var Email_WGT_OptIn = "Yes";
        var lead_source = "WG Popup to Lead";
        var property_optin_block = `<COLUMN>
    console.info("AV Opt-in:", Email_AV_OptIn);
    console.info("GAH Opt-in:", Email_GAH_OptIn);
    console.info("LAFLAG Opt-in:", Email_LAFLAG_OptIn);
    console.info("LASLC Opt-in:", Email_LASLC_OptIn);
    console.info("SB Opt-in:", Email_SB_OptIn);
    console.info("SV Opt-in:", Email_SV_OptIn);
    console.info("WG Opt-in:", Email_WGT_OptIn);
    // end setting property specific values for lead source and opt-ins
    // start our async serverless function
    async function runAcousticToken() {
      try {
        // request access token from Acoustic
        const responseAcousticGenerateAcccessToken = await axios.post(acousticTokenURL, acousticAccessTokenParams, configAccessToken).then()
        // grab access token from Acoustic
        var acousticAccessToken = responseAcousticGenerateAcccessToken.data.access_token;
        console.log("Access Token:", acousticAccessToken);
        // set headers to leverage access token from Acoustic
        var configBearerToken = {
        headers: { 'Content-Type': 'text/xml', 'Authorization': "Bearer " + acousticAccessToken }
        // set up payload
        var xmlBodyAddRecipient = `<Envelope>
                  <NAME>First Name</NAME>
                    <NAME>Last Name</NAME>
                    <NAME>Mailing Zip</NAME>
                    <NAME>UTM Campaign</NAME>
                    <NAME>CRM Lead Source</NAME>
                    <NAME>Account Name</NAME>
                    <VALUE>[not provided]</VALUE>
                    <NAME>CRM Enable Sync</NAME>
                    <NAME>CRM Contact Type</NAME>
        // make call with payload to add the recipient to our main db
        const responseAcousticAddRecipient = await axios.post(acousticAPIURL, xmlBodyAddRecipient, configBearerToken).then()
        console.log("Acoustic Add Response:", responseAcousticAddRecipient);
        console.info("Authentication for Access Token Complete °º¤ø,¸¸,ø¤º°`°º¤ø,¸ Acoustic ¸,ø¤°º¤ø,¸¸,ø¤º°`°º¤ø,¸  ");
        console.log("Payload:", xmlBodyAddRecipient);
        console.info("Recipient Added complete (っ◕‿◕)っ", email);
      } catch (error) {



app.use('/.netlify/functions/server', router); // path must route to lambda

module.exports = app;
module.exports.handler = serverless(app);

I don’t see how your repo could allow you to deploy your Express app successfully to Netlify. Could you share a URL to reproduce the issue?

No problem, here is the URL I am posting to:

For what it’s worth I am not receiving any errors when I deploy to Netlify.

Additionally let me know if you need to see the entire repo. I can look to make that public.

Sure sharing your repo would probably be the easiest way to go ahead with this.

Here is a link to the repo. Thank you for looking into this, I appreciate it!

I don’t have your environment variables to test this, but you do have a missing await at runAcousticToken();. It should be await runAcousticToken();. Not sure if it will fix it though.