Prerequisites Step 1: Create a Docker image Step 2: Authenticate to the public registry Step 3: Create a public repository Step 4: Push an image to Amazon ECR Public Step 5: Pull an image from the Amazon ECR Public Gallery Step 6: Delete a public image Step 7: Delete a public repository

Moving an image through its lifecycle in Amazon ECR Public

This quick start guide walks you through the steps needed to create a Docker image, publish the image to a public repository, pull the image down from the Amazon ECR Public Gallery, and then clean up the resources using the Docker CLI and the AWS CLI.

To use the AWS Management Console instead of the AWS CLI, see Creating an Amazon ECR public repository to store images.

For more information on the other tools available for managing your AWS resources, including the different AWS SDKs, IDE toolkits, and the Windows PowerShell command line tools, see http://aws.amazon.com/tools/.

Prerequisites

If you do not have the latest AWS CLI and Docker installed and ready to use, use the following steps to install both of these tools.

Install the AWS CLI

To use the AWS CLI with Amazon ECR, install the latest AWS CLI version. For information, see Installing the AWS Command Line Interface in the AWS Command Line Interface User Guide.

Install Docker

Docker is available on many different operating systems, including most modern Linux distributions, like Ubuntu, and even macOS and Windows. For more information about how to install Docker on your particular operating system, go to the Docker installation guide.

You do not need a local development system to use Docker. If you are using Amazon EC2 already, you can launch an Amazon Linux 2023 instance and install Docker to get started.

If you already have Docker installed, skip to Step 1: Create a Docker image.

To install Docker on an Amazon EC2 instance using an Amazon Linux 2023 AMI

Launch an instance with the latest Amazon Linux 2023 AMI. For more information, see Launching an instance in the Amazon EC2 User Guide.
Connect to your instance. For more information, see Connect to Your Linux Instance in the Amazon EC2 User Guide.
Update the installed packages and package cache on your instance.
```
sudo yum update -y
```
Install the most recent Docker Community Edition package.
```
sudo yum install docker
```
Start the Docker service.
```
sudo service docker start
```
Add the ec2-user to the docker group so you can execute Docker commands without using sudo.
```
sudo usermod -a -G docker ec2-user
```
Log out and log back in again to pick up the new docker group permissions. You can accomplish this by closing your current SSH terminal window and reconnecting to your instance in a new one. Your new SSH session will have the appropriate docker group permissions.
Verify that the ec2-user can run Docker commands without sudo.
```
docker info
```
Note
In some cases, you may need to reboot your instance to provide permissions for the ec2-user to access the Docker daemon. Try rebooting your instance if you see the following error:
```
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
```

Step 1: Create a Docker image

In this step, you create a Docker image of a simple web application, and test it on your local system or Amazon EC2 instance.

To create a Docker image of a simple web application

Create a file called Dockerfile. A Dockerfile is a manifest that describes the base image to use for your Docker image and what you want installed and running on it. For more information about Dockerfiles, go to the Dockerfile Reference.
```
touch Dockerfile
```
Edit the Dockerfile you just created and add the following content.
```
FROM public.ecr.aws/amazonlinux/amazonlinux:latest

# Install dependencies
RUN yum update -y && \
 yum install -y httpd

# Install apache and write hello world message
RUN echo 'Hello World!' > /var/www/html/index.html

# Configure apache
RUN echo 'mkdir -p /var/run/httpd' >> /root/run_apache.sh && \
 echo 'mkdir -p /var/lock/httpd' >> /root/run_apache.sh && \
 echo '/usr/sbin/httpd -D FOREGROUND' >> /root/run_apache.sh && \
 chmod 755 /root/run_apache.sh

EXPOSE 80

CMD /root/run_apache.sh
```
This Dockerfile uses the public Amazon Linux 2 image hosted on Amazon ECR Public. The RUN instructions update the package caches, installs some software packages for the web server, and then write the "Hello World!" content to the web servers document root. The EXPOSE instruction exposes port 80 on the container, and the CMD instruction starts the web server.
Build the Docker image from your Dockerfile.

Note
Some versions of Docker may require the full path to your Dockerfile in the following command, instead of the relative path shown below.
```
docker build -t hello-world .
```

List your container image.


docker images --filter reference=hello-world

Output:

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
hello-world         latest              e9ffedc8c286        4 minutes ago       194MB

Run the newly built image. The -p 80:80 option maps the exposed port 80 on the container to port 80 on the host system. For more information about docker run, go to the Docker run reference.
```
docker run -t -i -p 80:80 hello-world
```
Note
Output from the Apache web server is displayed in the terminal window. You can ignore the "Could not reliably determine the fully qualified domain name" message.
Open a browser and point to the server that is running Docker and hosting your container.
- If you are using an EC2 instance, this is the Public DNS value for the server, which is the same address you use to connect to the instance with SSH. Make sure that the security group for your instance allows inbound traffic on port 80.
- If you are running Docker locally, point your browser to http://localhost/.
- If you are using docker-machine on a Windows or Mac computer, find the IP address of the VirtualBox VM that is hosting Docker with the docker-machine ip command, substituting machine-name with the name of the docker machine you are using.
```
docker-machine ip machine-name
```
You should see a web page with your "Hello World!" statement.
Stop the Docker container by typing Ctrl + c.

Step 2: Authenticate to the public registry

After you have installed and configured the AWS CLI, authenticate the Docker CLI to your public registry. That way, the docker command can push to and pull images from an Amazon ECR public repository. The AWS CLI provides a get-login-password command to simplify the authentication process.

To authenticate Docker to an Amazon ECR public registry with get-login-password, run the aws ecr-public get-login-password --region us-east-1 command. The Amazon ECR Public registry requires authentication in the us-east-1 Region, so you need to specify --region us-east-1 each time you authenticate. The authentication token received gives you access to each public registry your IAM principal has access to. When passing the authentication token to the docker login command, use the value AWS for the username and specify public.ecr.aws, which is the common public registry URI.

Important

If you receive an error, install or upgrade to the latest version of the AWS CLI. For more information, see Installing the AWS Command Line Interface in the AWS Command Line Interface User Guide.


aws ecr-public get-login-password --region us-east-1 | docker login --username AWS --password-stdin public.ecr.aws

Step 3: Create a public repository

Now that you have an image to push to Amazon ECR Public, you can create a public repository. In this example, you create a public repository called ecr-tutorial to which you later push the hello-world:latest image. All public repositories that contain an image are publicly visible in the Amazon ECR Public Gallery so we will specify some catalog data for the repository.

Create a file named repositorycatalogdata.json with the following contents. For this tutorial we are going to include a repository logo, which is named myrepoimage.png and is in the same directory as the repositorycatalogdata.json file we are creating.

Note

When creating a repository logo, the supported image dimensions for both height and width should be a minimum of 60 pixels and a maximum of 2048 pixels. The maximum logo file size is 500 KB.


{
    "description": "This is a test repo for an Amazon ECR tutorial.",
    "architectures": [
        "x86"
    ],
    "operatingSystems": [
        "Linux"
    ],
    "logoImageBlob": "$(cat myrepoimage.png |base64 -w 0)",
    "aboutText": "This repository is used as a tutorial only.",
    "usageText": "This repository is not for public use."
}

Use the catalog data file we just created to run the following create-repository command. Your repository URI is included in the response, which you will need in the next step for pushing an image to the repository.


aws ecr-public create-repository \
     --repository-name ecr-tutorial \
     --catalog-data file://repositorycatalogdata.json \
     --region us-east-1

Step 4: Push an image to Amazon ECR Public

Now you can push your image to the Amazon ECR public repository you created in the previous section. You use the Docker CLI to push images, but there are a few prerequisites that must be satisfied for this to work properly:

The Amazon ECR Public authorization token has been configured with docker login.
The Amazon ECR public repository exists and the user has access to push to the repository.

After those prerequisites are met, you can push your image to your newly created repository in the default registry for your account.

To tag and push an image to Amazon ECR Public

List the images you have stored locally to identify the image to tag and push.


docker images

Output:

REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
hello-world         latest              e9ffedc8c286        4 minutes ago       241MB

Tag the image to push to your repository with your public repository URI which was in the response to the create-repository call you made in the previous step.
```
docker tag hello-world:latest public.ecr.aws/registry_alias/ecr-tutorial
```

Push the image.


docker push public.ecr.aws/registry_alias/ecr-tutorial

Output:

The push refers to a repository [public.ecr.aws/registry_alias/ecr-tutorial] (len: 1)
e9ae3c220b23: Pushed
a6785352b25c: Pushed
0998bf8fb9e9: Pushed
0a85502c06c9: Pushed
latest: digest: sha256:215d7e4121b30157d8839e81c4e0912606fca105775bb0636b95EXAMPLE size: 1569

Step 5: Pull an image from the Amazon ECR Public Gallery

After your image has been pushed to your Amazon ECR public repository, you can pull it from other locations. It is considered best practice to authenticate prior to pulling images from the public gallery. If you need to reauthenticate, see Step 2: Authenticate to the public registry.

Note

Unauthenticated pulls are allowed, but have a lower rate limit than authenticated pulls. For more information, see Amazon ECR Public service quotas.

View your repository on the Amazon ECR Public Gallery.


https://gallery.ecr.aws/registry_alias/ecr-tutorial


docker pull public.ecr.aws/registry_alias/ecr-tutorial/hello-world:latest

Step 6: Delete a public image

If you decide that you no longer need or want an image in one of your repositories, you can delete it with the batch-delete-image command. To delete an image, you must specify the repository that it is in and either a imageTag or imageDigest value for the image. The example below deletes an image in the hello-world repository with the image tag latest.


aws ecr-public batch-delete-image \
      --repository-name ecr-tutorial \
      --image-ids imageTag=latest \
      --region us-east-1

Step 7: Delete a public repository

If you decide that you no longer need or want an entire repository of images, you can delete the repository. By default, you cannot delete a repository that contains images; however, the --force flag allows this. To delete a repository that contains images (and all the images within it), run the following command.


aws ecr-public delete-repository \
      --repository-name ecr-tutorial \
      --force \
      --region us-east-1

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Document Conventions

Amazon ECR Public Gallery

Public registries