Docker Image Creation and Dockerfile Basics

Study Notes

A Docker image is a reusable asset that can be deployed on any host.
The interactive method for creating docker images is simple and easy to follow.
The docker run command image_name:tag_name will create a container from a specified image.
The docker file approach is more difficult and time-consuming but does better in continuous delivery environments.
Each file that makes up a Docker image is called an image layer. In a docker image, layers build on top of each other in stages to create images.
The container layer is a thin writable layer that docker adds each time a container is launched from an image.
The parent image is the first layer of a Docker image and provides the basic blocks for your container environments.
A base image is an empty first layer that allows you to build your Docker images from scratch.
A Docker build command builds a Docker image from a Dockerfile and a “context”.
The “context” here refers to the set of files located at the PATH or URL specified as the positional argument to the build command.
The context can include any of the files located in the current working directory or any of the files referenced in the Dockerfile.
The docker build command can be used to build an image for a local or remote machine.
The docker build command can be used to build an image for a specific version of Docker.