Understanding how to import a map.osm file into a

Question

I was just reading a tutorial HERE.

I am assigned with the following task:

The task is to create a Docker image that has PostgreSQL installed. The PostgreSQL database should be PostGIS-enabled. The Docker image should also allow quick and easy import of an .osm map data file into the database. The database should contain a routable osm-based road network which can be used to run simple default pgRouting queries (shortest path, A star).

I know how to do the initial and final part of it but i am a bit confused about the following part:

The Docker image should also allow quick and easy import of an .osm map data file into the database.

How do i make this possible ? Dockerfile ? but still how ?