Inspect changes to files or directories on a container’s filesystem

docker diff container-id

the docker push command to push your image to the Docker Hub registry:

docker push [dockerhub username]/[image name]

Tag the image with your username.

The Docker Hub naming convention is to tag your image with [dockerhub username]/[image name]. To do this, tag your previously created image python-hello-world to fit that format.

$ docker tag python-hello-world [dockerhub username]/python-hello-world

Log in to the Docker registry account by entering docker login on your terminal

$ docker login
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: 

Run a MongoDB server from the Docker Store

$ docker container run --detach --publish 8081:27017 --name mongo mongo:3.4

inspect the running docker processes:

$ ps -ef

run bash inside container by using the docker container exec command

$ docker container exec -it [container ID] bash