Could not translate host name “db” to address using Postgres, Docker Compose and Psycopg2

Question

In one folder I have 3 files: base.py, Dockerfile and docker-compose.yml.

base.py:

import psycopg2

conn = psycopg2.connect(\"dbname=\'b         


        

Answer 1

If you're using docker-compose first add this line to your .yml:

environment:
  - "POSTGRES_HOST_AUTH_METHOD=trust"

After that you start only you db docker:

docker-compose up db

It should start normally with a message like:

Recreating db... done
Attaching to db
db_1           | ********************************************************************************
db_1           | WARNING: POSTGRES_HOST_AUTH_METHOD has been set to "trust". This will allow
db_1           |          anyone with access to the Postgres port to access your database without
db_1           |          a password, even if POSTGRES_PASSWORD is set. See PostgreSQL
db_1           |          documentation about "trust":
db_1           |          https://www.postgresql.org/docs/current/auth-trust.html
db_1           |          In Docker's default configuration, this is effectively any other
db_1           |          container on the same system.
db_1           | 
db_1           |          It is not recommended to use POSTGRES_HOST_AUTH_METHOD=trust. Replace
db_1           |          it with "-e POSTGRES_PASSWORD=password" instead to set a password in
db_1           |          "docker run".
db_1           | ********************************************************************************