Amazon web services – Troubleshooting AWS ECS Service Discovery and Nginx Reverse Proxy Configuration

I am attempting to set up an environment on AWS ECS with a React frontend served by Nginx, and two backend services (Django apps) that should communicate via Nginx as a reverse proxy. I’ve configured ECS Service Discovery for service-to-service communication but encounter errors when the Nginx container starts, indicating that the upstream hosts cannot be found.

error message from Task logs –

What I’ve Tried:

1. Configuring nginx.conf and default.conf to resolve the services using ECS Service Discovery names.
2. Setting the resolver in nginx.conf to Docker’s default DNS resolver 127.0.0.11.
3. Updating ECS Service Discovery settings for Nginx and the Django apps to ensure proper service registration.
4. Rebuilding and redeploying Docker images after configuration changes.
5. Examining ECS logs to find errors like [emerg] host not found in upstream.

In ECS, I’ve created the namespace and service discovery for the nginx and for my django app. Images are below;
Django-app
Nginx-React

This is the default.conf

upstream healthmanagement {
    server healthmanagement-service.glucocare-services:8000;
}

upstream chat {
    server chat-service.glucocare-services:8000;
}

server {

listen 80;

location /api/ {
    proxy_pass http://healthmanagement;
}

location /chat/ {
    proxy_pass http://chat;
}

# Serve Django static files
location /static/django {
    alias /app/healthcare_project/static/;  
}

# Static Django media files
location /media/ {
    alias /app/healthcare_project/media/;  
}

# Serve React static files
location /static/ {
    alias /usr/share/nginx/html/build/static/;  
}

# Main location block to serve the React app
location / {
    root /usr/share/nginx/html/build;  
    try_files $uri $uri/ /index.html;
}

}

nginx.conf

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    resolver 172.31.0.2 valid=30s;  

    include /etc/nginx/conf.d/*.conf;  # Include all conf files from conf.d directory
}