How to connect to Ethereum node (geth) via IPC from outside of docker container

Question

I'm using docker-compose to run ethereum node with Docker:

  # ethereum node
  ethereum:
    container_name: ethereum-node
    image: ethereum/client-go:v1.8.10
    ports:
      - "8545:8545"
      - "8546:8546"
      - "30303:30303"
      - "30303:30303/udp"
    volumes:
      - ./ethereum-data/.ethereum:/root/.ethereum
      - ./ethereum-data/keystore:/root/.ethereum/testnet/keystore
      - ./ethereum-data/.ethash:/root/.ethash
    restart: always
    command: -verbosity=4 --fast --cache=512 --testnet

After docker-compose up i can see in the log:

INFO [07-03|11:40:19] IPC endpoint opened url=/root/.ethereum/testnet/geth.ipc

and i'm able to connect to it from the container with

docker exec -ti ethereum-node geth attach ipc:/root/.ethereum/testnet/geth.ipc

Though i've mounted volumes and i can see geth.ipc:

$ls ./ethereum-data/.ethereum/testnet/
.        ..       geth     geth.ipc keystore

i can't connect to from host:

$geth attach ./ethereum-data/.ethereum/testnet/geth.ipc Fatal: Unable to attach to remote geth: dial unix ./ethereum-data/.ethereum/testnet/geth.ipc: connect: connection refused

How can i do it? I'd prefer to use IPC (though i've succeed to connect over HTTP RPC on 8545).