无法将主机名“postgres”转换为地址：未知主机

Question

Setting up a Django project but I am getting a warning about setting up postgres as shown in the title, but I am unsure what this means.

Full warning message:

RuntimeWarning: Got an error checking a consistent migration history performed for database connection 'default': could not translate host name "postgres" to address: Unknown host

And here is how I define postgres in my settings.py :

DATABASES = {
"default": {
    "ENGINE": "django.db.backends.postgresql_psycopg2",
    "NAME": os.environ.get("DB_NAME", "dbname"),
    "USER": os.environ.get("DB_USER", "dbuser"),
    "PASSWORD": os.environ.get("DB_PASSWORD", "dbpassword"),
    "HOST": os.environ.get("DB_HOST", "postgres"),
    "PORT": os.environ.get("DB_PORT", "5432"),
}

}

Would it possible for someone to walk me through what is going wrong here? I have no idea.

Answer 1

In order to use django with postgresql you need a reachable postgresql server.

You can install and run it locally : https://www.postgresql.org/download/

Then you postgresql server will be reachable on your localhost interface. This DB_HOST config variable represent the address where your django server should contact your postgresql server.

So you can change the default value of your DB_HOST environment variable from "postgres" to "localhost", or directly set it into your environment ( using a .env file for example )