Docker Images and Dockerfile

Images

A Docker image is a snapshot of a file and operating system with libraries and application executables. In essence, an image is a recipe or template for creating a container. It’s similar to how some computer languages let you define a reusable class template for instantiating objects of the same type.

Any number of containers can be started from a single image. This permits scaling on production servers, although you’re unlikely to launch multiple containers from the same image during development.

The Docker Hub provides a repository of commonly-used images for:

• dependencies such as NGINX, MySQL, MongoDB, Elasticsearch, Redis, etc.

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