Which line should you modify in the file?

You plan to create an image that will contain a .NET Core application.

You have a Dockerfile file that contains the following code. (Line numbers are included for reference only.)

You need to ensure that the image is as small as possible when the image is built.

Which line should you modify in the file?
A . 1
B . 3
C . 4
D . 7

View Answer

Answer: A

Explanation:

Multi-stage builds (in Docker 17.05 or higher) allow you to drastically reduce the size of your final

image, without struggling to reduce the number of intermediate layers and files. With multi-stage

builds, you use multiple FROM statements in your Dockerfile. Each FROM instruction can use a

different base, and each of them begins a new stage of the build. You can selectively copy

artifacts from one stage to another, leaving behind everything you don’t want in the final image.

References: https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds