could not translate host name "db" to address: Temporary failure in name resolution

Question

I am trying to build postgres with django from official docker documentation samples link nevertheless for unknown reason i am getting following error which i tried to solve without success. Please of help.

This is output with error i got:

╰─ docker-compose up
[+] Running 2/2
 ⠿ Container postgresdjango_db_1   Created                                                                                                                            0.0s
 ⠿ Container postgresdjango_web_1  Recreated                                                                                                                          2.5s
Attaching to db_1, web_1
db_1   | chmod: changing permissions of '/var/lib/postgresql/data': Operation not permitted
db_1   | Error: Database is uninitialized and superuser password is not specified.
db_1   |        You must specify POSTGRES_PASSWORD to a non-empty value for the
db_1   |        superuser. For example, "-e POSTGRES_PASSWORD=password" on "docker run".
db_1   |
db_1   |        You may also use "POSTGRES_HOST_AUTH_METHOD=trust" to allow all
db_1   |        connections without a password. This is *not* recommended.
db_1   |
db_1   |        See PostgreSQL documentation about "trust":
db_1   |        https://www.postgresql.org/docs/current/auth-trust.html
db_1 exited with code 1
web_1  | Watching for file changes with StatReloader
web_1  | Performing system checks...
web_1  |
web_1  | System check identified no issues (0 silenced).
web_1  | Exception in thread django-main-thread:
web_1  | Traceback (most recent call last):
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
web_1  |     self.connect()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 33, in inner
web_1  |     return func(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 200, in connect
web_1  |     self.connection = self.get_new_connection(conn_params)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 33, in inner
web_1  |     return func(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/postgresql/base.py", line 187, in get_new_connection
web_1  |     connection = Database.connect(**conn_params)
web_1  |   File "/usr/local/lib/python3.10/site-packages/psycopg2/__init__.py", line 122, in connect
web_1  |     conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
web_1  | psycopg2.OperationalError: could not translate host name "db" to address: Temporary failure in name resolution
web_1  |
web_1  |
web_1  | The above exception was the direct cause of the following exception:
web_1  |
web_1  | Traceback (most recent call last):
web_1  |   File "/usr/local/lib/python3.10/threading.py", line 1009, in _bootstrap_inner
web_1  |     self.run()
web_1  |   File "/usr/local/lib/python3.10/threading.py", line 946, in run
web_1  |     self._target(*self._args, **self._kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/autoreload.py", line 64, in wrapper
web_1  |     fn(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/core/management/commands/runserver.py", line 121, in inner_run
web_1  |     self.check_migrations()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 486, in check_migrations
web_1  |     executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/migrations/executor.py", line 18, in __init__
web_1  |     self.loader = MigrationLoader(self.connection)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/migrations/loader.py", line 53, in __init__
web_1  |     self.build_graph()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/migrations/loader.py", line 220, in build_graph
web_1  |     self.applied_migrations = recorder.applied_migrations()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/migrations/recorder.py", line 77, in applied_migrations
web_1  |     if self.has_table():
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/migrations/recorder.py", line 55, in has_table
web_1  |     with self.connection.cursor() as cursor:
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 33, in inner
web_1  |     return func(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 259, in cursor
web_1  |     return self._cursor()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 235, in _cursor
web_1  |     self.ensure_connection()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 33, in inner
web_1  |     return func(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 218, in ensure_connection
web_1  |     with self.wrap_database_errors:
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/utils.py", line 90, in __exit__
web_1  |     raise dj_exc_value.with_traceback(traceback) from exc_value
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
web_1  |     self.connect()
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 33, in inner
web_1  |     return func(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 200, in connect
web_1  |     self.connection = self.get_new_connection(conn_params)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 33, in inner
web_1  |     return func(*args, **kwargs)
web_1  |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/postgresql/base.py", line 187, in get_new_connection
web_1  |     connection = Database.connect(**conn_params)
web_1  |   File "/usr/local/lib/python3.10/site-packages/psycopg2/__init__.py", line 122, in connect
web_1  |     conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
web_1  | django.db.utils.OperationalError: could not translate host name "db" to address: Temporary failure in name resolution
web_1  |





links:
  - db:db

EDIT:

docker-copmpose.yaml

version: "3.9"
   
services:
  db:
    image: postgres
    volumes:
      - ./data/db:/var/lib/postgresql/data
  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - .:/code
    ports:
      - "8000:8000"
    environment:
      - POSTGRES_NAME=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres
    depends_on:
      - db

Answer 1

db_1   | Error: Database is uninitialized and superuser password is not specified.
db_1   |        You must specify POSTGRES_PASSWORD to a non-empty value for the
db_1   |        superuser. For example, "-e POSTGRES_PASSWORD=password" on "docker run".

As you can see above, you have not set password.

You should set password in docker-compose.yml file.

version: "3.9"
   
services:
  db:
    image: postgres
    volumes:
      - ./data/db:/var/lib/postgresql/data
  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - .:/code
    ports:
      - "8000:8000"
    environment:
      - POSTGRES_NAME=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=YOUR_PASSWORD_HERE
    depends_on:
      - db

You should set password in database.ini file like this:

[postgresql]
host=localhost
database=suppliers
user=postgres
password=SecurePas$1

Or you can use "docker run -e POSTGRES_PASSWORD=password" command.

Answer 2

Just add POSTGRES_PASSWORD to the db instance too.

version: "3.9"
   
services:
  db:
    image: postgres
    volumes:
      - ./data/db:/var/lib/postgresql/data
    environment:
      - POSTGRES_PASSWORD=postgres
  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - .:/code
    ports:
      - "8000:8000"
    environment:
      - POSTGRES_NAME=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres
    depends_on:
      - db

Answer 3

Could you show us the docker-compose content? There may be a problem with your network configuration.