POST response body empty on NGINX server - node.js

Question

I am running a Node.js application on a NGINX server with an SSL certificate. I just realized that all of my POST/PUT requests that the application attempts to return to the front end are empty; essentially the response is an empty string. The application works fine in a local environment as well as Heroku, with all images and GET requests resolving as they should.
I am expecting JSON to come back in my HTTP responses, whether the request was successful or had errors. Right now I am getting an empty string. Below is a screenshot of my response, you will notice that the Content Length header is completely missing.
Screenshot of my headers
Essentially, is there something wrong with my NGINX proxy that is preventing my HTTP responses to come back blank?
Below is my NGINX configuration file
server {
listen 80;
server_name blah.com;
rewrite ^/(.*) https://blah.com/$1 permanent;
}
server {
# SSL configuration
#
listen 443 ssl default_server;
ssl_certificate XXX;
ssl_certificate_key XXX;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_prefer_server_ciphers on;
ssl_ciphers 'EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH';
root /var/www/html;
# Add index.php to the list if you are using PHP
index index.html index.htm index.nginx-debian.html;
server_name blah.com;
location / {
proxy_pass http://127.0.0.1:8080;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
Bellow are the access logs that application is generating:
24.123.110.242 - - [27/Jul/2017:21:10:45 +0000] "POST /sign-up HTTP/1.1" 400 5 "https://app.quiqmath.com/sign-up" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36"
24.123.110.242 - - [27/Jul/2017:21:10:47 +0000] "POST /socket.io/?__sails_io_sdk_version=0.11.0&__sails_io_sdk_platform=browser&__sails_io_sdk_language=javascript&EIO=3&transport=polling&t=Ls5upja&sid=4mrvSlNzMv9ZCetHAAAL HTTP/1.1" 502 182 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8"
24.123.110.242 - - [27/Jul/2017:21:10:47 +0000] "GET /socket.io/?__sails_io_sdk_version=0.11.0&__sails_io_sdk_platform=browser&__sails_io_sdk_language=javascript&EIO=3&transport=polling&t=Ls5ujej&sid=4mrvSlNzMv9ZCetHAAAL HTTP/1.1" 200 4 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8"
24.123.110.242 - - [27/Jul/2017:21:10:48 +0000] "GET /socket.io/?__sails_io_sdk_version=0.11.0&__sails_io_sdk_platform=browser&__sails_io_sdk_language=javascript&EIO=3&transport=polling&t=Ls5upzL HTTP/1.1" 200 101 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8"
24.123.110.242 - - [27/Jul/2017:21:10:49 +0000] "GET /socket.io/?__sails_io_sdk_version=0.11.0&__sails_io_sdk_platform=browser&__sails_io_sdk_language=javascript&EIO=3&transport=polling&t=Ls5up_l&sid=XSl8MUuC7TH6v4iLAAAM HTTP/1.1" 200 5 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8"

Answer 1

In Sails.js applications that have a version that are greater than 0.11.X and less than 1.0, the res.badRequest() response strips the data out of the response when the application is in production mode. To fix this, either upgrade the Sails.js application to 1.X and the documentation can be found here on how to do it, or you can comment out the following line in the api/responses/badRequest.js file:
// Only include errors in response if application environment
// is not set to 'production'. In production, we shouldn't
// send back any identifying information about errors.
if (sails.config.environment === 'production') {
//data = undefined;
}