feat(aws-eks): Allow atomic flag for helm chart

* Add atomic flag for helm chart construct
* Update unit test
* Update README

packages/aws-cdk-lib/aws-eks/README.md

@@ -1403,6 +1403,9 @@ new eks.HelmChart(this, 'NginxIngress', {
 });
 ```
 
+Helm can treat operations as atomic, if so, upgrade process rolls back changes made in case of failed upgrade.
+The --wait flag will be set automatically if --atomic is used.
+
 ### OCI Charts
 
 OCI charts are also supported.

packages/aws-cdk-lib/aws-eks/lib/helm-chart.ts

@@ -84,6 +84,13 @@ export interface HelmChartOptions {
    * @default - CRDs are installed if not already present
    */
   readonly skipCrds?: boolean;
+
+  /**
+   * Whether or not Helm should treat this operation as atomic; if set, upgrade process rolls back changes
+   * made in case of failed upgrade. The --wait flag will be set automatically if --atomic is used.
+   * @default false;
+  */
+  readonly atomic?: boolean;
 }
 
 /**
@@ -148,6 +155,8 @@ export class HelmChart extends Construct {
     const createNamespace = props.createNamespace ?? true;
     // default to not skip crd installation
     const skipCrds = props.skipCrds ?? false;
+    // default to not use atomic operations
+    const atomic = props.atomic ?? false;
 
     this.chartAsset?.grantRead(provider.handlerRole);
 
@@ -168,6 +177,7 @@ export class HelmChart extends Construct {
         Repository: this.repository,
         CreateNamespace: createNamespace || undefined,
         SkipCrds: skipCrds || undefined,
+        Atomic: atomic || undefined,
       },
     });
   }

packages/aws-cdk-lib/aws-eks/test/helm-chart.test.ts

@@ -249,4 +249,26 @@ describe('helm chart', () => {
       Template.fromStack(stack).hasResourceProperties(eks.HelmChart.RESOURCE_TYPE, { SkipCrds: true });
     });
   });
+
+  test('should disable atomic operations by default', () => {
+    // GIVEN
+    const { stack, cluster } = testFixtureCluster();
+
+    // WHEN
+    new eks.HelmChart(stack, 'MyChart', { cluster, chart: 'chart' });
+
+    // THEN
+    const charts = Template.fromStack(stack).findResources(eks.HelmChart.RESOURCE_TYPE, { Atomic: true });
+    expect(Object.keys(charts).length).toEqual(0);
+  });
+  test('should enable atomic operations when specified', () => {
+    // GIVEN
+    const { stack, cluster } = testFixtureCluster();
+
+    // WHEN
+    new eks.HelmChart(stack, 'MyAtomicChart', { cluster, chart: 'chart', atomic: true });
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties(eks.HelmChart.RESOURCE_TYPE, { Atomic: true });
+  });
 });