(ecs): introduce IContainerImage interface for custom container image providers #36504
Description
Describe the feature
The ContainerDefinitionOptions.image property currently accepts only the abstract ContainerImage class, which limits extensibility for custom container image providers. Users who need custom implementations (e.g., integration with private registries, dynamic image selection, or custom authentication) must extend the abstract class, which is cumbersome and prevents easy external package distribution.
Introducing an IContainerImage interface would enable users and third-party library authors to provide custom container image implementations without extending the abstract class, following the Open/Extensible principle of CDK.
Use Case
Enterprise Custom Registry Integration
Organizations using private container registries (JFrog Artifactory, Harbor, GitLab Registry, etc.) need custom authentication and image resolution logic:
// Currently required: must extend abstract class
class ArtifactoryImage extends ecs.ContainerImage {
constructor(private registry: string, private image: string) {
super(); // Required but adds no value
}
public bind(scope: Construct, containerDefinition: ecs.ContainerDefinition) {
const credentials = this.getCredentialsFromVault();
return {
imageName: `${this.registry}/${this.image}`,
repositoryCredentials: { credentialsParameter: credentials },
};
}
}Proposed Solution
Introduce an IContainerImage interface and update the type signature
/**
* Interface for container image providers.
*/
export interface IContainerImage {
/**
* Called when the image is used by a ContainerDefinition.
*/
bind(scope: Construct, containerDefinition: ContainerDefinition): ContainerImageConfig;
}
/**
* Constructs for types of container images
*/
export abstract class ContainerImage implements IContainerImage {
// Existing static factory methods and implementation unchanged
}
// Update the property type
export interface ContainerDefinitionOptions {
readonly image: IContainerImage; // Changed from: ContainerImage
// ...
}
Other Information
No response
Acknowledgements
- I may be able to implement this feature request
- This feature might incur a breaking change
AWS CDK Library version (aws-cdk-lib)
2.x
AWS CDK CLI version
2.x
Environment details (OS name and version, etc.)
all