How to resolve "django.db.utils.OperationalError: could not translate host name "db" to address: Name or service not known"

I'm trying to run a Django dockerized project on my local machine. I'm new to dockers so,I'm just trying to run this project to learn how dockers work.I'm sure the project code is absolutely fine to work with because it runs fine on my friend's local machine.

I tried

docker-compose -f global-compose.yml up

This is my global-compose.yml

version: '2'
services:
  ### redis
  the-redis:
    image: redis:3.2.7-alpine
    ports:
      - '6379:6379'
    volumes:
      - ../data/redis:/data

  db:
    image: postgres:10.20
    environment:
      - PGDATA=/var/lib/postgresql/data/pgdata
      - POSTGRES_MULTIPLE_DATABASES=postgres,payments,justlegal_attorney_scheduler
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres
    volumes:
      - db_data:/var/lib/postgresql/data/pgdata
      - ~/backups:/backups
      - ./postgres:/docker-entrypoint-initdb.d
    ports:
      - '5433:5432'

  web:
    build: ./gotlaw
    env_file: ./env_web
    entrypoint: ./django_instances.sh
    volumes:
      - ./gotlaw:/code
      - /static:/static
    environment:
      REDIS_HOST: the-redis
      REDIS_PORT: 6379
      REDIS_URL: the-redis:6379
    expose:
      - '8000'
    depends_on:
      - db
      - the-redis
    restart: always

  nginx:
    hostname: local.got.law
    image: nginx:1.16.0
    volumes:
      - ./deploy/nginx/conf.d:/etc/nginx/conf.d:ro
      - ./deploy/nginx/pages/errors:/var/www/errors
      - ./deploy/nginx/conf.d/stunnel:/etc/nginx/conf.d/stunnel:ro
      - /static:/static
    ports:
      - '80:80'
      - '443:443'
    depends_on:
      - web
#      - payments-client
#      - attorney-scheduler
#      - client-scheduler
#    links:
#      - attorney-scheduler:attorney-scheduler-server
#      - client-scheduler:client-scheduler-server





volumes:
  db_data:

On my friend's local and some other local machines it just start running the website but on my machine I face this error

Starting gotlaw-main_the-redis_1 ... done
Starting gotlaw-main_db_1        ... done
Starting gotlaw-main_web_1       ... done
Starting gotlaw-main_nginx_1     ... done
Attaching to gotlaw-main_the-redis_1, gotlaw-main_db_1, gotlaw-main_web_1, gotlaw-main_nginx_1
nginx_1      | 2023/07/20 14:20:38 [warn] 1#1: the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/default.conf:9
nginx_1      | nginx: [warn] the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/default.conf:9
db_1         | ls: cannot open directory '/docker-entrypoint-initdb.d/': Permission denied
the-redis_1  | 1:C 20 Jul 14:20:37.094 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
gotlaw-main_db_1 exited with code 2
the-redis_1  |                 _._                                                  
the-redis_1  |            _.-``__ ''-._                                             
the-redis_1  |       _.-``    `.  `_.  ''-._           Redis 3.2.7 (00000000/0) 64 bit
the-redis_1  |   .-`` .-```.  ```\/    _.,_ ''-._                                   
the-redis_1  |  (    '      ,       .-`  | `,    )     Running in standalone mode
the-redis_1  |  |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
the-redis_1  |  |    `-._   `._    /     _.-'    |     PID: 1
the-redis_1  |   `-._    `-._  `-./  _.-'    _.-'                                   
the-redis_1  |  |`-._`-._    `-.__.-'    _.-'_.-'|                                  
the-redis_1  |  |    `-._`-._        _.-'_.-'    |           http://redis.io        
the-redis_1  |   `-._    `-._`-.__.-'_.-'    _.-'                                   
the-redis_1  |  |`-._`-._    `-.__.-'    _.-'_.-'|                                  
the-redis_1  |  |    `-._`-._        _.-'_.-'    |                                  
the-redis_1  |   `-._    `-._`-.__.-'_.-'    _.-'                                   
the-redis_1  |       `-._    `-.__.-'    _.-'                                       
the-redis_1  |           `-._        _.-'                                           
the-redis_1  |               `-.__.-'                                               
the-redis_1  | 
the-redis_1  | 1:M 20 Jul 14:20:37.097 # Server started, Redis version 3.2.7
the-redis_1  | 1:M 20 Jul 14:20:37.097 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
the-redis_1  | 1:M 20 Jul 14:20:37.097 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
the-redis_1  | 1:M 20 Jul 14:20:37.097 * DB loaded from disk: 0.000 seconds
the-redis_1  | 1:M 20 Jul 14:20:37.097 * The server is now ready to accept connections on port 6379
web_1        | Traceback (most recent call last):
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 244, in ensure_connection
web_1        |     self.connect()
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, 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 225, 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 26, 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 203, 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: Name or service not known
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 "/code/manage.py", line 21, in <module>
web_1        |     execute_from_command_line(sys.argv)
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/core/management/__init__.py", line 446, in execute_from_command_line
web_1        |     utility.execute()
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/core/management/__init__.py", line 440, in execute
web_1        |     self.fetch_command(subcommand).run_from_argv(self.argv)
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 414, in run_from_argv
web_1        |     self.execute(*args, **cmd_options)
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 460, in execute
web_1        |     output = self.handle(*args, **options)
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/core/management/commands/createcachetable.py", line 54, in handle
web_1        |     self.create_table(db, cache._table, dry_run)
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/core/management/commands/createcachetable.py", line 62, in create_table
web_1        |     if tablename in connection.introspection.table_names():
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/introspection.py", line 56, in table_names
web_1        |     with self.connection.cursor() as cursor:
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, 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 284, in cursor
web_1        |     return self._cursor()
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 260, in _cursor
web_1        |     self.ensure_connection()
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, 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 243, 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 91, 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 244, in ensure_connection
web_1        |     self.connect()
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, 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 225, 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 26, 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 203, 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: Name or service not known
web_1        | 
web_1        | Traceback (most recent call last):
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/db/backends/base/base.py", line 244, in ensure_connection
web_1        |     self.connect()
web_1        |   File "/usr/local/lib/python3.10/site-packages/django/utils/asyncio.py", line 26, 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 225, 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 26, 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 203, 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: Name or service not known
web_1        | 

The error occurs because your web_1 container (running the django app) is trying to access host name 'db', which is the service specified to run your postgreSQL database, but it could not find any instance of it running.

The clue is in the logs:

db_1         | ls: cannot open directory '/docker-entrypoint-initdb.d/': Permission denied
gotlaw-main_db_1 exited with code 2

These two logs show:

1. the problem why the postgres container could not start properly,
2. and the postgres container exiting.

There are several reasons why you might encounter a permissions denied error, but for now, try running docker as administrator and try again.