Starting the build

Implicitely looks for a Dockerfile file in the current directory:

docker build .
docker build --file Dockerfile .

Syntax: –file / -f

. stands for the context (in this case, current directory) of the build process. This makes sense if copying files from filesystem, for instance. IMPORTANT: Avoid contexts (directories) overpopulated with files (even if not actually used in the recipe).

You can define a specific name for the image during the build process.

Syntax: -t imagename:tag. If not defined :tag default is latest.

docker build -t mytestimage .

The last line of installation should be Successfully built …: then you are good to go.
Check with docker images that you see the newly built image in the list…

Then let’s check the ID of the image and run it!

docker images

docker run f9f41698e2f8
docker run mytestimage
docker run f9f41698e2f8 https://cdn-images-1.medium.com/max/1600/1*_NQN6_YnxS29m8vFzWYlEg.png