Create Mongo docker image and add user to database

Question

I'm attempting to figure out how to make a docker container that automatically creates the database user profile. I'm using a Dockerfile and figured I could include the commands for creating the user there.

Does anyone know how to do this? I am still a beginner in docker so any help would be much appreciated.

FROM mongo:latest

RUN mongo &&\
    use tewtdb &&\
    db.createUser({user: '<user>', pwd: '<pwrd>', roles[{role: 'dbOwner', db: 'tewtdb'}]})

EXPOSE 27017

CMD ["mongod"]