Quiz: several containers

Question 1 of 10

Container names on the default network and in a network of your own, Docker's DNS, a neighbour's port, the stack commands up -d, restart and down, health checks and depends_on. The questions follow the lessons “Container networking: names and ports” and “docker compose: a stack in one file”.

10 questions · threshold 70%

Read the output

Both containers were started without `--network`. Why can't app find db?

$ sudo docker ps --format '{{.Names}} {{.Status}}'
app Up 2 minutes
db Up 2 minutes
$ sudo docker logs --tail 1 app
app: db unreachable: nc: bad address 'db'

db has no -p 5432:5432.
Containers on the default network cannot see each other at all.
db is not listening on port 5432.
Nobody resolves container names on the default network — app asks the host's DNS servers.

A–D or ↵ Sign in to answer

Quiz: several containers

Both containers were started without --network. Why can't app find db?

Both containers were started without `--network`. Why can't app find db?