How to connect using psql to a subd located inside a docker container?

Question

PostgreSQL

Good afternoon, I have PostgresSQL running inside a docker container and I want to connect to it using the psql utility:

sudo psql -h localhost -p 5432 -U postgres -d master

but something goes wrong and when passing authentication, I permanently get an error:

FATAL: password authentication failed for user "postgres"

I'm running the whole thing on Ubuntu 19.10 via docker-compose:

version: "3.4"

networks:
  default_network:
    ipam:
      config:
        - subnet: 18.129.0.0/16

services: 
  postgres:
    image: postgres:11
    networks:
      - default_network
    ports:
      - ${DB_EXTERNAL_PORT}:${DB_INTERNAL_PORT}
    environment:
      POSTGRES_DB: ${DB_NAME}
      POSTGRES_USER: ${USER}
      POSTGRES_PASSWORD: ${PASSWORD}
    volumes:
    - ./db_data:/var/lib/postgresql/data

and accordingly environment variables:

DB_NAME=master
USER=postgres
PASSWORD=postgres
DB_EXTERNAL_PORT=5432
DB_INTERNAL_PORT=5432

It would be funny if it really was a password error, but I couldn't make it wrong 15 times in a row, including copy-paste. Thanks in advance to those who will not pass by, I suspect the error is that when connecting to the container, you need to log in under a certain linux user, but I'm not sure.
UPD:
I forgot to look at the container logs

DETAIL: Role "postgres" does not exist.

but anyway, how can a role not exist if it is set in POSTGRES_USER or is there a role under the role here?
UPD 1:
The user exists and the python code easily connects to the database when it is in an adjacent container on the same subnet. Apparently, I have not configured the permissions configuration located in the pg_hba.conf file. documentation
It remains to understand which address space the localhost belongs to for the contents of the container.