Docker Image Registry (Local & Remote Storage) | Overview.

Docker Image Registry (Local & Remote Storage) - Overview.

Scope:

• Intro,
• Docker Images:  Stored Locally,
• Additional locations inside /var/lib/docker/
• where exactly locally are docker images stored in (linux, windows & macOs)
• Where Docker Images Stored Remotely,
• Basic Image management command,
• Summary.

Intro:

• Docker images are stored locally on twtech system by the Docker Engine, and remotely in registries like Dockerhub / Elastic Container Registry (ECR).
• Here’s twtech detailed overview of both:

 1.  Docker Images:  Stored Locally

 Linux (default storage driver: overlay2)

Docker images are stored under:

# swift

/var/lib/docker/

Specifically, image layers and metadata are in:

# swift

/var/lib/docker/overlay2/

Additional locations inside /var/lib/docker/:

Directory	Purpose
overlay2/	Image layers (merged filesystems)
image/	Metadata about images
containers/	Running container data
volumes/	Volume data
network/	Network configuration

 macOS & Windows

• Docker uses a lightweight VM (via Docker Desktop, WSL2 on Windows, or HyperKit on macOS). 
• The images are stored inside the virtual machine, not directly on the host filesystem.
• twtech can interact with image and container via Docker commands, but can't easily browse to them in Finder or File Explorer.

• On Windows (WSL2):
  Images are stored inside the WSL2 virtual disk:

# kotlin

 

\\wsl$\docker-desktop-data\version-pack-data\community\docker\overlay2\

• On macOS:
  Stored in a VM disk file, typically located at:

# bash

 

~/Library/Containers/com.docker.docker/

or inside:

# bash

 

~/Library/Containers/com.docker.docker/Data/vms/

 NB: 

• Since twtech can’t interact with the actual image files directly, it uses Docker CLI to manage image files.

 2. Docker Images:  Stored Remotely

Public Registries:

• Docker Hub (https://hub.docker.com)
• GitHub Container Registry
• Amazon ECR,  etc.

twtech Basic management command:

# bash

docker pull twtechwebapp

Docker:

1. Contacts Docker Hub.
2. Downloads image layers.
3. Caches them locally.

 3. Viewing Local Images

Use:

# bash

docker images       # To get more detailed info:

# bash

docker image inspect twtechspringbootapp   #To see where Docker’s data is stored:

# bash

docker info | grep Root  #To se the output one comand as the input for another.

Sample output:

# bash 

Docker Root Dir: /var/lib/docker

twtech Summary

Platform	Local Storage Path
Linux.	/var/lib/docker/overlay2/
macOS.	Inside Docker Desktop VM (~/Library/Containers/...)
Windows.	Inside WSL2/Docker Desktop VM (\\wsl$\...)

NB

• To manage or remove images, twtech always use the Docker CLI (docker image rm, docker system prune, etc.).