Connect the Microservices

Fix name resolution between containers with a user-defined network.

A advanced Docker challenge worth 20 points. Solve it hands-on in a real Docker environment in your browser - no local setup, no fake shells.

The Challenge

Scenario: The web nginx proxy forwards to http://api/ — and keeps crashing with "host not found in upstream". Both containers sit on Docker's default bridge, where container names don't resolve.

Tasks:

• Confirm the failure: docker ps -a, docker logs web
• Create a user-defined bridge network shopnet
• Run api on it: docker run -d --name api --network shopnet busybox sh -c 'mkdir -p /www && echo "{\"service\":\"orders\",\"status\":\"ok\",\"orders\":42}" > /www/index.html && httpd -f -p 80 -h /www'
• Run web on it too (image web:v1, port 8080 → 80)
• Browser panel: JSON from the api, proxied through nginx

Commands to learn: docker network create, docker run --network, embedded DNS

Run check when done.