Containers
Containers are used to bundle your application along with it’s dependencies, libraries together so that It can run consistently across different environments like developer’s local machine to testing or production.
Docker containers provide a way to package and deploy your applications in a more efficient and scalable way compared to traditional virtual machines (VMs).
Docker Hub
Docker Hub is like app store for docker images. It’s a repository of container images where you can find images from others to run or use as base for your own image.
It is a centralized platform for developers to store, share, and distribute Docker images.
Docker Hub is docker’s official cloud-based registry, which is public and used by default when installing Docker. It is a popular choice for hosting container images.
Docker Hub allows you to access a vast collection of pre-built Docker images created by the Docker community and official repositories maintained by Docker.
Docker Registry
It is the underlying technology that powers Docker Hub.
Docker registry is a service that stores, versions & distributes docker images. Registries can be public or private and can be hosted on-premise or in the cloud.
A Docker registry is a storage and distribution system for Docker images. It enables you to host your own repository to store Docker images within your infrastructure or on a cloud platform of your choice.
This gives you control over the storage and distribution of Docker images within your organization.
Docker Engine
Docker engine is the core component of docker platform, responsible for creating, running and managing containers.
It consists of 3 items - A daemon called containerd, a REST api and a cli tool called docker.
- Server - Contains a long-running daemon process called dockerd.
- Daemon - A background process that manages docker objects.
- REST API - It’s an interface which allows users and applications to interact with the docker daemon to manage objects like containers, images, networks and volumes.
- Docker CLI - A command line tool which provides users the ability to interact with docker daemon. It uses docker rest api to communicate with docker daemon.
Docker Engine is built on containerd, a project of the Cloud Native Computing Foundation (CNCF).
Docker commands
Some basic docker commands to practice.