The Dockerfile build instructions
So far, we have looked at the integrated build system, the
Dockerfile syntax and a sample life cycle, including how a sample
Dockerfile is leveraged to generate an image and how a container gets spun off from that image. In this section, we will introduce the
Dockerfile instructions, their syntax, and a few fitting examples.
The FROM instruction
FROM instruction is the most important one and it is the first valid instruction of a
Dockerfile. It sets the base image for the build process. The subsequent instructions would use this base image and build on top of it. The
docker build system lets you flexibly use the images built by anyone. You can also extend them by adding more precise and practical features to ...