Pull and Push Docker Image to Azure Container Registry using Azure Devops pipeline

When you want to develop and implement the container application in Azure. The first and main step you would execute is to build the images and push them into the our own private Registry (ex: Azure Container registry). In this post, I will explain how to Pull and Push Docker Image to Azure Container Registry using Azure DevOps pipeline

If your solution is going to use base image from public repo then best practice in DevOps to pull & push the trusted public image to ACR, post that we need to use same in our custom solution build.

what is Azure container Registry (ACR)

Azure Container Registry also is the similar as hub.docker.com but is provided by azure cloud. The Azure Container registry can be private and can be used by only one team or users who have access. So, users with access can push and pull images.

It provides geo-replication so that images pushed in one datacenter in one region gets replicated in all the connected configured datacenters and gets deployed simultaneously to Kubernetes clusters in respective locations.

Pull and push Docker Image

The purpose of this article is to provide steps to guide how to pull the image from public repository and provide commands to push and pull images from registry using the Azure DevOps pipeline.

There can be two options when you want to push the container images into ACR.

Option 1: Import the pre-existing Docker image from the docker hub (docker.io)/public registry and deploy it to AKS.

Option 2: Create a new custom image based on our solution (we can use push and pull other public registry and use in our solution as base image to build our solution), push it to ACR, and then deploy it to AKS.

Note: If you are using Azure default Agent or your own Agent, then decide which type of image your pulling and pushing. If the image is build on windows then the window Agent need to use for the push and pull or linux Agent if image is build with linux as base image. In my case, i am pulling the linux based image from registry.k8s.io to my ACR. Post this action, we will refer the same image during the nginx ingress installation in my AKS

Push Image to Azure Container Registry

Step 1 : Login to Azure Container Registry with Non-Interactive mode

Syntax:  docker login –username demo –password example

Step 2 : Pull the image and tag the image with registry prefix

In my case, I need to pull the image from public repository (registry.k8s.io) and from my ACR i need to refer this image during the ingress installation in AKS cluster. To be able to push Docker images to Azure Container Registry, they need to be tagged with the login Server name of the Registry. These tags are used for routing purposes when we push these Docker images to Azure. In simple words, Docker tags convey useful information about a specific image version/variant

Syntax:  docker pull [OPTIONS] NAME[:TAG|@DIGEST]
docker tag SOURCE_IMAGE[:TAG] TARGET_IMAGE[:TAG]

Pull Image to Azure Container Registry

Step 3 : Pull the image with registry name prefix

Now that the image is tagged (in step 2), we can use the “docker push” command to push this image to Azure Container Registry;

Syntax:  docker push [OPTIONS] NAME[:TAG|@DIGEST]

This operation might take a few minutes and you will se the image being uploaded to Azure Container Registry in the console.

Note: To pull image directly onto docker-compose, kubernetes yml files, use appropriate logins. Usually in these scenarios, docker login is the first step before docker-compose up is called, so that images get pulled successfully

For this above example, to explain in step by step i used bash task for each action but we can do all to gether in single bask task in pipeline as shown below.

Full YAML code for Pipeline