Docker Course Labs

Lab Solution

Roll back to the earlier deployment:

docker-compose -f labs/networking/compose.yml up -d

And you can scale up with the Compose CLI:

docker-compose -f labs/networking/compose.yml up -d --scale rng-api=3

You'll see two new API containers created.

Follow the logs from all API containers:

docker-compose -f labs/networking/compose.yml logs -f rng-api

Use the app at http://localhost:8090 and you'll see different API containers generating numbers.

Inspect the API containers and you'll see compose sets the same network alias for each of them:

docker inspect networking_rng-api_1
"Aliases": [
  "rng-api",
  "b382ce0e8ffc"
]

Any containers with the same alias will get returned in the DNS response for that domain name.