How to connect to dockerized database from outside of the docker network on local machine

Question

I have created this docker container for my postgres database on my windows machine:

docker run -d -p 5432:5432 --rm --name pg_container -v C:\pgdata:/var/lib/postgresql/data --env-file ./database.env postgres:latest

And if I run docker exec -it pg_container bash and run psql command I can create a database name mydb (in the real situation, this is being created by a flask application).

If I run

docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' tma_pg_db_container

I will get 172.0.0.2

Now I want to connect directly to the database from outside of the container.

psql postgresql://postgres:<PASSWORD>@<IP_ADDRESS>:5432/tma_pg_db

What should I use for IP_ADDRESS ?

Please note that I have another psotgres database created on the system level and not in the container. For that one, I use localhost it, and works fine, it connects. If I use localhost, it connects to the system-level database not the container inside the docker container.

Answer 1

You should use localhost . That will connect to the port you published using the docker run -p option.

(If you are using a VM-based solution like Docker Machine or Docker Toolbox, you need its IP address instead; docker-machine ip will tell you what it is. If you're calling from a different host, use the physical host's IP address, the same way you would if the service wasn't running in a container.)

The two important corollaries to this are that (a) you don't need debugging tools like docker exec to interact with your database; and (b) you don't need to look up the docker inspect IP address (which also doesn't work in many common contexts).