ECR

Summary#

Amazon Elastic Container Registry (ECR) is a fully managed container registry that allows you to store container images. You can create as many repositories as you'd like that are free. As you push container images to your repository, you're charged for the storage of these images, which can accrue over time. Additionally, ECR charges different data transfer rates for private vs public repositories.

Pricing Dimensions#

Dimension	Description
Container Image Storage	ECR charges a rate per month for the amount of storage per GB you store for container images.
Data Transfer	ECR charges different rates for data transfer from public and private repositories.

Storage Costs per ECR Repository#

Determining the cost per Container Repository can be a lot of effort, especially if you have a large quantity of images. To calculate the storage cost per container repository:

List all of your container images.
Collect the image digest from each.
Determine just the unique digests of the layers in your container repository.
Get the size of each unique digest.

If you prefer not to do this manually yourself, Vantage will compute the size and corresponding cost of all repositories automatically when you connect an AWS account.

Lifecycle Policies#

ECR stores every container image you push to a registry by default. Over time, the storage of all of these images can add up. Amazon offers a primitive called a lifecycle Policy that allows you to set conditions for having Amazon clean up images on your behalf. There are two types of lifecycle policies:

Lifecycle Policy	Description
`imageCountMoreThan`	ECR allows you to define a certain number of images to retain and anything over that count will be cleaned up. For example, if you set a lifecycle Policy with a `imageCountMoreThan` value of 10, your most recent 10 images will always be kept.
`sinceImagePushed`	ECR allows you to set lifecycle policies with a value of `sinceImagePushed`, which has a value of a certain number of days. So, for example, if you have a lifecycle Policy applied with a `sinceImagePushed` value of seven, ECR will delete images when they are older than seven days.

Note

When you apply a lifecycle Policy, it is evaluated immediately. So, if you have 500 images in a repository and impose a lifecycle policy of 10, as soon as that policy is applied ECR will delete the 490 oldest images.

Example `imageCountMoreThan` Lifecycle Policy#

Here's an example of how to impose a lifecycle Policy via the AWS CLI using the value of imageCountMoreThan:

aws ecr put-lifecycle-policy \
    --repository-name "vantage/mcyolo" \
    --lifecycle-policy-text "file://policy.json"

Where the content of the file for policy.json is the following:

{
  "rules": [
     {
       "rulePriority": 1,
       "description": "Expire images over a count of 10",
       "selection": {
         "tagStatus": "untagged",
         "countType": "imageCountMoreThan",
         "countNumber": 10
       },
       "action": {
         "type": "expire"
       }
     }
  ]
}

Example `sinceImagePushed` Lifecycle Policy#

Here's an example of how to impose a Lifecycle Policy via the AWS CLI using the value of sinceImagePushed:

aws ecr put-lifecycle-policy \
    --repository-name "vantage/mcyolo" \
    --lifecycle-policy-text "file://policy.json"

Where the content of the file for policy.json is the following:

{
  "rules": [
     {
       "rulePriority": 1,
       "description": "Expire images older than 14 days",
       "selection": {
         "tagStatus": "untagged",
         "countType": "sinceImagePushed",
         "countUnit": "days",
         "countNumber": 14
       },
       "action": {
         "type": "expire"
       }
     }
  ]
}

Contribute

Contribute to this page on GitHub or join the #cloud-costs-handbook channel in the Vantage Community Slack.

Last updated Jul 11, 2021

ECR