@aws-cdk/aws-ecr-assets

AWS CDK Docker Image Assets

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The APIs of higher level constructs in this module are experimental and under active development. They are subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model and breaking changes will be announced in the release notes. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

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This module allows bundling Docker images as assets.

Images are built from a local Docker context directory (with a Dockerfile), uploaded to ECR by the CDK toolkit and/or your app's CI-CD pipeline, and can be naturally referenced in your CDK app.

import { DockerImageAsset } from '@aws-cdk/aws-ecr-assets';

const asset = new DockerImageAsset(this, 'MyBuildImage', {
  directory: path.join(__dirname, 'my-image')
});

The directory my-image must include a Dockerfile.

This will instruct the toolkit to build a Docker image from my-image, push it to an AWS ECR repository and wire the name of the repository as CloudFormation parameters to your stack.

By default, all files in the given directory will be copied into the docker build context. If there is a large directory that you know you definitely don't need in the build context you can improve the performance by adding the names of files and directories to ignore to a file called .dockerignore, or pass them via the exclude property. If both are available, the patterns found in exclude are appended to the patterns found in .dockerignore.

The ignoreMode property controls how the set of ignore patterns is interpreted. The recommended setting for Docker image assets is IgnoreMode.DOCKER. If the context flag @aws-cdk/aws-ecr-assets:dockerIgnoreSupport is set to true in your cdk.json (this is by default for new projects, but must be set manually for old projects) then IgnoreMode.DOCKER is the default and you don't need to configure it on the asset itself.

Use asset.imageUri to reference the image (it includes both the ECR image URL and tag.

You can optionally pass build args to the docker build command by specifying the buildArgs property:

const asset = new DockerImageAsset(this, 'MyBuildImage', {
  directory: path.join(__dirname, 'my-image'),
  buildArgs: {
    HTTP_PROXY: 'http://10.20.30.2:1234'
  }
});

You can optionally pass a target to the docker build command by specifying the target property:

const asset = new DockerImageAsset(this, 'MyBuildImage', {
  directory: path.join(__dirname, 'my-image'),
  target: 'a-target'
})

Pull Permissions

Depending on the consumer of your image asset, you will need to make sure the principal has permissions to pull the image.

In most cases, you should use the asset.repository.grantPull(principal) method. This will modify the IAM policy of the principal to allow it to pull images from this repository.

If the pulling principal is not in the same account or is an AWS service that doesn't assume a role in your account (e.g. AWS CodeBuild), pull permissions must be granted on the resource policy (and not on the principal's policy). To do that, you can use asset.repository.addToResourcePolicy(statement) to grant the desired principal the following permissions: "ecr:GetDownloadUrlForLayer", "ecr:BatchGetImage" and "ecr:BatchCheckLayerAvailability".