Docker images is an executable package of software built by docker file. This helps to containerize an application. This uses operating-system-level virtualization to deliver software in packages called containers. he way Docker does this is by packaging an application and its dependencies in a virtual container that can run on any computer. This containerization allows for much better portability and efficiency when compared to Virtual Machines.
Some of the key components of docker are as below
- Docker Engine – Creates and manages the container
- Docker image – All application code in container
- Docker Hub – Cloud based repository for sharing images
- Docker file – Contains instructions to build docker images
- Docker Registry – Place to store the images.
These Images are located in Azure Container Registry and need to get the images from azure to local machine. So, we are going to use Azure CLI commands to download the images.
Prerequisite:
- Docker Desktop – provides GUI to work on docker containers, docker images and docker networks
- Azure CLI
Let’s find the steps on using Azure CLI command to download the images.
1.Once Azure CLI is installed, open “Microsoft Azure Command Prompt.”
2.Login to Azure CLI using below command
az loginThis will give the list of available subscriptions for the logged in user.
3.Now connect to the required subscription from which images are to be pulled.
az account set --subscription SDCloud-DEVELOPMENT
4.Connect to the Azure container Registry from which images are to be pulled.
az acr login -name acrsdclouddev
On Successful login, use below docker command to pull images.
docker pull acrsdclouddev.azurecr.io/maxcloudcoreview-sdcloud-dev
We can find the downloaded image in Docker desktop, under “Local” tab.
The main advantage of docker is that it provides an isolated environment (Docker container) where application can run consistently in different platform. This also fastens the deployment process.
References:
https://learn.microsoft.com/en-us/cli/azure/get-started-with-azure-cli
https://hadoan.medium.com/how-to-pull-docker-image-from-azure-container-registry-5fa1a50c21d9
Docker Image (geeksforgeeks.org)
Azure DevOps-CI/CD Implementation – Athen
Hope the above-mentioned steps helps in initial connection to Azure CLI and to download images to local machine.