Push your first image to a private Docker container registry using the Docker CLI

An Azure container registry stores and manages private Docker container images, similar to the way Docker Hub stores public Docker images. You use the Docker Command-Line Interface (Docker CLI) for login, push, pull, and other operations on your container registry.

For more background and concepts, see the overview

Prerequisites

  • Azure container registry - Create a container registry in your Azure subscription. For example, use the Azure portal or the Azure CLI 2.0.
  • Docker CLI - To set up your local computer as a Docker host and access the Docker CLI commands, install Docker Engine.

Log in to a registry

Run docker login to log in to your container registry with your registry credentials.

The following example passes the ID and password of an Azure Active Directory service principal. For example, you might have assigned a service principal to your registry for an automation scenario.

docker login myregistry.azurecr.io -u xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx -p myPassword

Tip

Make sure to specify the fully qualified registry name (all lowercase). In this example, it is myregistry.azurecr.io.

Steps to pull and push an image

The follow example downloads the Nginx image from the public Docker Hub registry, tags it for your private Azure container registry, pushes it to your registry, then pulls it again.

1. Pull the Docker official image for Nginx

First pull the public Nginx image to your local computer.

docker pull nginx

2. Start the Nginx container

The following command starts the local Nginx container interactively on port 8080, allowing you to see output from Nginx. It removes the running container once stopped.

docker run -it --rm -p 8080:80 nginx

Browse to http://localhost:8080 to view the running container. You see a screen similar to the following one.

Nginx on local computer

To stop the running container, press [CTRL]+[C].

3. Create an alias of the image in your registry

The following command creates an alias of the image, with a fully qualified path to your registry. This example specifies the samples namespace to avoid clutter in the root of the registry.

docker tag nginx myregistry.azurecr.io/samples/nginx

4. Push the image to your registry

docker push myregistry.azurecr.io/samples/nginx

5. Pull the image from your registry

docker pull myregistry.azurecr.io/samples/nginx

6. Start the Nginx container from your registry

docker run -it --rm -p 8080:80 myregistry.azurecr.io/samples/nginx

Browse to http://localhost:8080 to view the running container.

To stop the running container, press [CTRL]+[C].

7. (Optional) Remove the image

docker rmi myregistry.azurecr.io/samples/nginx

Concurrent Limits

In some scenarios, executing calls concurrently might result in errors. The following table contains the limits of concurrent calls with "Push" and "Pull" operations on Azure container registry:

Operation Limit
PULL Up to 10 concurrent pulls per registry
PUSH Up to 5 concurrent pushes per registry

Next steps

Now that you know the basics, you are ready to start using your registry! For example, start deploying container images to an Azure Container Service cluster.