404 GET Requests turns into 502 Gateway Errors? NGINX or other issues?

Hey guys,

I have been having issues with my MERN project lately.One is that I keep getting 404 errors and the other is now I see a 502 Error when I visit my DO IP address.

Today I was making changes to my signup and login code. I noticed that I would get 404 errors when trying to test it out and I would also get the same errors in POSTMAN.

I decided to visit my Explore page and would get a GET request 404 error. Which was strange because this wasn’t happening yesterday.

Then in POSTMAN I did a GET request to /api/blog/posts and to api/users/users and I didn’t get a list of posts or users. Instead I saw the index.html from React.

I went to my DO IP address and would see the same 404 error in my Explore page.I then got rid of all of my changes for the day and that didn’t help.

After a couple a minutes I went back to my ip address and now see a 502 Gateway Error. I went back to POSTMAN to do GET request to /api/blog/posts and to api/users/users and now I see 502 Gateway Error

I’m not sure what the issue. If it’s NGINX, my code, or something else. I can’ do anything with my project now.

Any help would be appreciated.


server {
        listen 80 default_server;
        listen [::]:80 default_server;

        # SSL configuration
        # listen 443 ssl default_server;
        # listen [::]:443 ssl default_server;
        # Note: You should disable gzip for SSL traffic.
        # See: https://bugs.debian.org/773332
        # Read up on ssl_ciphers to ensure a secure configuration.
        # See: https://bugs.debian.org/765782
        # Self signed certs generated by the ssl-cert package
        # Don't use them in a production server!
        # include snippets/snakeoil.conf;

        root /var/www/*PROJECT NAME*/client/build/index.html;

        # Add index.php to the list if you are using PHP
        index index.html index.htm index.nginx-debian.html;

        server_name *DO IP ADDRESS*;

        location ^~ /assets/ {
                gzip_static on;
                expires 12h;
                add_header Cache-Control public;

        location / {
                proxy_http_version 1.1;
                proxy_cache_bypass $http_upgrade;

                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_pass http://localhost:3000;
                client_max_body_size 50M;
location = /favicon.ico {
  log_not_found off;


const path = require("path")
const express = require('express')
const mongoose = require('mongoose')
const cookieParser = require('cookie-parser')
const app = express()

const blogAPI = require('./api/blogApi')
const auth = require('./api/auth')
const users = require('./api/users')

_/* Connect to Database */_
mongoose.connect(process.env.DBURI, {
    useNewUrlParser: true,
    useUnifiedTopology: true
}).then(() => console.log('MongoDB connected...'))
    .catch(err => console.log(err))


_/* POST form handling */_
app.use(express.urlencoded({ extended: true }));

_/* Routing */_

app.use('/api/blog', blogAPI)
app.use('/api/auth', auth)
app.use('/api/users', users)

app.use('/public', express.static(path.join(__dirname, 'public')))

// Display React in production
app.use(express.static(path.join(__dirname, '/../client', 'build')))
app.get('*', function (req, res) {
    res.sendFile(path.join(__dirname, '/../client', 'build', 'index.html'))

app.listen(process.env.PORT, () => console.log("Server started!"))

module.exports = app;


class PostService {
    _//  list_
    _static_ list() {
        return Post.find({})
            .then((posts) => {
                return posts


_/* CORS */_

const corsOptions = {
    origin: `${process.env.FRONTEND}`,
    credentials: true,
    preflightContinue: false,
    optionsSuccessStatus: 204


_/* Start of Routing */_

_/* Code associated with blog posts */_

_// list_
router.get('/posts', (req, res, next) => {
        .then((posts) => {


const axiosPrivate = axios.create({
    baseURL: `${process.env.REACT_APP_URL}/api`

Explore Page

useEffect(() => {
        const fetchPosts = _async_ () => {
            try {
                let response = await axiosPrivate.get('/blog/posts')
            } catch (error) {
    }, [])

Can you make sure your nginx configuration is ok? If you run this nginx command in your server, it will test your default nginx config file to see if its formatted ok:

sudo nginx -t

The output should say that it’s ok and it’s successful like this (from my own Linux server):

Screenshot 2023-04-04 at 9.01.54 PM

Thanks for the reply. I have resolved the issue by fixing my proxy pass to point to my node server. I had changed it before thinking that it was going to resolve another issue and it didn’t. I forgot to change it back.

Oh good! I’m glad you found it! Happy Coding!

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