How to generate a Postgresql Dump from a Docker container?

Question

I would like to have a way to enter into the Postgresql container and get a data dump from it.

Answer 1

Although the mountpoint solution above looked promising, the following is the only solution that worked for me after multiple iterations:

docker run -it  -e PGPASSWORD=my_password postgres:alpine  pg_dump  -h hostname -U my_user my_db > backup.sql

What was unique in my case: I have a password on the database that needs to be passed in; needed to pass in the tag (alpine); and finally the hosts version of the psql tools were different to the docker versions.