PostgreSQL with Docker
Internal
Overview
In its simplest form,
docker run postgres
command starts a transient Posgres container instance that does not expose any port on the local host, it is initialized on the fly to allow access to any user and uses an anonymous local volume that will not be reattached to during the next run. To get a usable Postgres instance we can shut down and restart and that regains access to stored data between restarts, we should use the following:
- simplest image - data is lost
- external volume
- port mapping.
Running a Transient Instance
Postgres binds by default on port 5432 and this is the port published by the following command:
docker run -p 5432:5432/tcp postgres
The command will implicitly create a local anonymous volume that will linger around after the container stops. The data on the anonymous local volume can be accessed by starting the stopped container. Test
You can attach to the container with:
docker exec -it <container-id> bash