aws-eks: support `--atomic` flag for helm commands

[michaelfedell]

Describe the feature

Support the Helm CLI --atomic flag as a prop to the aws-cdk.aws-eks.HelmChart construct. This would enable a user to perform their install/upgrade as an atomic operation, rolling back or uninstalling if the operation fails.

Use Case

Currently, if the resources installed by helm do not successfully initialize and the --wait flag is true, then helm will fail to send a response back to the custom resource in time. Once the first invocation fails, subsequent attempts will fail with the following error:

Error: UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress

After the max attempts, the CloudFormation stack will be marked as UPDATE_ROLLBACK_FAILED. Forcing the user to manually rollback the helm release as described in this issue on the helm repo

Proposed Solution

This could be supported with an additional, optional ResourceProperty passed to the custom resource handler and used in the constructed helm command.

aws-cdk/packages/@aws-cdk/aws-eks/lib/kubectl-handler/helm/__init__.py

Line 149 in 877ad71

def helm(verb, release, chart = None, repo = None, file = None, namespace = None, version = None, wait = False, timeout = None, create_namespace = None):

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

CDK version used

2.28.1

Environment details (OS name and version, etc.)

MacOS, TypeScript

[peterwoodworth]

Thanks for the request @michaelfedell,

You're right, this would be a pretty easy implementation done just by introducing a new property and using it similar to the other flags.

I am marking this issue as p2, which means that we are unable to work on this immediately.

Check out our contributing guide if you're interested in contributing yourself - there's a low chance the team will be able to address this soon but we'd be happy to review a PR 🙂