local-nginx-tutorial/eg3/README.md

e.g. 3: Create an Ningx Reverse Proxy With Docker

How To Run Multiple Docker Containers Under One URL

Backend only

How to test it:

1. Comment all other containers
2. Run docker compose build & docker compose up
3. Test by curl localhost:5000, should return {"version":"1.0.0"}

Frontend only

How to test it:

1. Comment all other containers
2. Run docker compose build & docker compose up
3. Test by curl localhost, should return a html file (as /eg3/frontend/index.html)

Backend + Frontend

In this section, we test frontend container can cross-communicate with backend container.

Steps:

1. Comment out proxy container
2. Remove exposed of both containers, as we they don't need expose their ports to outside environment. We just want to test their cross-communication in the same docker network
   1. port 80 for frontend;
   2. port 5000 for backend;
3. Run docker compose build & docker compose up
4. Create a network: docker network create mynetwork
5. Add containers into network
   1. docker network connect mynetwork backend
   2. docker network connect mynetwork frontend
6. Inspect mynetwork has containers docker network inspect mynetwork
7. Test network:
   1. Enter frontend container: docker exec -it frontend /bin/sh
   2. Make a request to backend: curl http://backend:5000
   3. Get response {"version": "1.0.0"}

Proxy using nginx

In this section, we test we can reach both frontend and backend from proxy container or computer itself

Steps:

1. Uncomment all container in docker-compose.yaml
2. Build container and initiate them via docker compose up
3. These container are not in mynetwork
4. Enter proxy container via docker exec -it proxy /bin/sh
5. From the proxy container, try to reach other containers
   1. Frontend
      1. curl http://frontend
      2. curl http://localhost to visit port 80
   2. Backend
      1. curl http://backend:5000
      2. curl http://localhost/api
6. Exit the container; In normal terminal, we can still reach frontend and backend
   1. curl http://localhost to visit frontend
   2. curl http://localhost/api to visit backend