1FROM golang:latest 2# All these steps will be cached 3RUN mkdir /project 4WORKDIR /project
latest tag can cause breakages when a new version of an image is released. You can never rely on the assumption that the
latest tag points to a specific version of an image.
It is recommended to always use a specific tagged image, e.g.
ubuntu:12.04. That way you always know exactly what variant of an image is being used.