nginx reverse proxy not finding backend service in docker-comopse

Question

I have the following docker-compose.yaml

version: '3'

services:
  webapp:
    image: example/webapp
    build:
      context: app
    restart: always
    ports:
      - ":8181"
    deploy:
      replicas: 3
    volumes:
      - secret-store:/app/data
    env_file:
      - .env
    networks:
      - bridged_network

  nginx:
    image: example/reverseproxy
    build:
      context: reverseproxy
    ports:
      - "8181:80"
    depends_on:
      - webapp

networks:
  bridged_network:
    driver: bridge

volumes:
  secret-store:

The nginx image is being built as follows

FROM nginx:latest

RUN rm /etc/nginx/conf.d/*
COPY nginx.conf /etc/nginx/conf.d/default.conf

Where nginx.conf

server {

  listen 80;

  location / {
    proxy_pass http://webapp:8181;
  }
}

However in the nginx container logs:

nginx: [emerg] host not found in upstream "webapp" in /etc/nginx/conf.d/default.conf:6

Why is nginx failing to discover webapp service?

Answer 1

Is your nginx reverse proxy in the same network as the service? It looks like they are not in the same network.