I’m trying to deploy my app on a server with docker compose:

services:
  frontend:
    container_name: frontend
    depends_on:
      - backend
    build:
      context: frontend
      dockerfile: ./Dockerfile
    ports:
      - 80:80
    environment:
      NODE_EVN: production
    networks:
      - app-network

  backend:
    container_name: backend
    depends_on:
      - db
    build:
      context: backend
      dockerfile: ./Dockerfile
    ports:
      - 8000:8000
    environment:
      NODE_EVN: production
      DB_URL: mongodb://db/dbname
    networks:
      - app-network

  db:
    container_name: db
    image: mongo:latest
    ports:
      - 27017:27017
    volumes:
      - dbname:/data/spares
    networks:
      - app-network

volumes:
  dbname:

networks:
  app-network:

My frontend container has ngingx installed to deliver compiled react app and serve as a reverse proxy to backend api. nginx.conf:

{
    listen 80;

    location / {
        root /usr/share/nginx/html;
        index index.html index.htm;
        try_files $uri $uri/ /index.html;
    }

    location /api/v1/ {
        proxy_pass http://backend:8000/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_redirect off;
        proxy_buffering off;
        proxy_cache off;
    }
}

Frontend works, but I’m getting 404 when trying to access backend:

frontend      | <my ip address> - - [30/Jul/2024:18:34:38 +0000] "GET /api/v1/ HTTP/1.1" 404 153 "-" "curl/8.5.0" "-"

I tried to docker exec to frontend container and curl from there – Ok, got 200 response.
What am I doing wrong? How can I configure nginx to proxy /api/v1/ to backend ?

One small thing. My app is running under /myapp/, but on separate vm.
So they reverse proxied to it:

location /myapp/ {
        proxy_pass http://<my vm IP-address>:80/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_redirect off;
        proxy_buffering off;
        proxy_cache off;
}

So it looks like
-> reverse proxy to my vm : serve frontend from container and reverse proxy api requests to backend in another container.

I have tried to change locations in my nginx.conf to /spares/ and /spares/api/v1/ accordingly, but it didn’t work.