Docker repositories and Docker HUB

Docker - Overview and how to use it

3 min read

Published Jul 13 2025

CLIContainersDevOpsDockerImagesNetworksVolumes

What is a Docker Repository?

A Docker repository is a collection of related Docker images, typically different versions or variants of the same application. Each image in a repository is tagged to distinguish versions, configurations, or architectures. Repositories are often hosted on a Docker registry, with the most common being Docker Hub.

Docker Hub

Docker Hub website where you can search for publicly available official and unofficial images. Official images are marked with a blue tick icon.

Open

Docker Hub (hub.docker.com) is the default public registry where Docker pulls images from unless another registry is specified. It hosts:

Official images maintained by Docker or trusted vendors
Community-contributed images from individuals or companies
Private repositories (for paid plans)

When you run:

docker pull ubuntu

it’s implicitly pulling from Docker Hub’s library/ubuntu repository.

Official Repositories

These are curated and maintained either by Docker or the original software maintainers. They are:

Verified for security and quality
Well-documented
Regularly updated
Reviewed for best practices

Examples: nginx, postgres, node, redis, alpine, etc.

You can recognise them on Docker Hub by the official image badge and simple names with no namespace prefix:

docker pull nginx

Unofficial/Community Repositories

These are created by individuals or companies and may:

Be outdated
Contain security risks
Lack proper documentation
Be useful for niche or custom use cases

These are namespaced and typically look like:

docker pull myuser/nginx-custom

While many are high-quality, caution is advised — always check the Dockerfile, reviews, and update history before using them in production.

Best Practices

Always prefer official images when available.
For third-party images, read the Dockerfile, check update frequency, and verify the publisher.
Pin to a specific version tag instead of using latest, to avoid surprises.

Useful list of official images

Here's a list of widely used and trusted official images on Docker Hub:

Image	Description
`ubuntu` / `debian`	Base OS images, often used for custom setups
`alpine`	Minimalist Linux distribution (5MB), great for small, secure containers
`node`	Node.js runtime for JavaScript apps
`nginx`	High-performance web server and reverse proxy
`httpd`	Apache HTTP Server
`redis`	In-memory key-value store, great for caching
`postgres`	PostgreSQL database
`mysql`	MySQL database
`mongo`	MongoDB NoSQL database
`python`	Python runtime with optional prebuilt images
`golang`	Go language development environment
`openjdk`	Java runtime and development kits
`busybox`	Tiny Unix utility suite, good for lightweight containers
`traefik`	Modern reverse proxy and load balancer (also available in Docker Hub)
`caddy`	Powerful, modern web server with automatic HTTPS, reverse proxy, and configuration via simple `Caddyfile`. Ideal for hosting, load balancing, and TLS management with minimal setup.
`docker`	Docker CLI and engine inside containers (for CI/CD workflows)