Merge pull request #1779 from aws-observability/addReleaseVersionNodeGroups

Update Ec2 Cluster stack to fetch NodeGroup releaseVersion

Author: HudsonHumphries

cdk_infra/lib/stacks/eks/ec2-cluster-stack.ts

@@ -8,6 +8,25 @@ import {
 } from 'aws-cdk-lib/aws-eks';
 import { ManagedPolicy } from 'aws-cdk-lib/aws-iam';
 import { GetLayer } from '../../utils/eks/kubectlLayer';
+import { StringParameter } from 'aws-cdk-lib/aws-ssm';
+
+function getReleaseVersion(amiType: string, clusterVersion: string, scope: Construct): string {
+  let parameterName: string;
+
+  // https://docs.aws.amazon.com/eks/latest/userguide/retrieve-ami-id.html
+  if (amiType === NodegroupAmiType.AL2_X86_64) {
+    parameterName = `/aws/service/eks/optimized-ami/${clusterVersion}/amazon-linux-2/recommended/release_version`;
+  } else if (amiType === NodegroupAmiType.AL2_ARM_64) {
+    parameterName = `/aws/service/eks/optimized-ami/${clusterVersion}/amazon-linux-2-arm64/recommended/release_version`;
+  } else {
+    throw new Error(`Unsupported amiType: ${amiType}`);
+  }
+
+  // Fetch and return the release version from the SSM parameter
+  return StringParameter.fromStringParameterAttributes(scope, `NodeGroupReleaseVersion-${clusterVersion}-${amiType}`, {
+    parameterName,
+  }).stringValue;
+}
 
 export class EC2Stack extends Stack {
   cluster: eks.Cluster;
@@ -22,6 +41,7 @@ export class EC2Stack extends Stack {
       eks.ClusterLoggingTypes.CONTROLLER_MANAGER,
       eks.ClusterLoggingTypes.SCHEDULER
     ];
+
     this.cluster = new eks.Cluster(this, props.name, {
       clusterName: props.name,
       vpc: props.vpc,
@@ -31,14 +51,17 @@ export class EC2Stack extends Stack {
       clusterLogging: logging,
       kubectlLayer: GetLayer(this, props.version)
     });
+
     const lt = new ec2.LaunchTemplate(this, `${props.name}-launch-template`, {
       requireImdsv2: true,
       httpEndpoint: true,
       httpPutResponseHopLimit: 2,
       httpTokens: ec2.LaunchTemplateHttpTokens.REQUIRED
     });
+
     const clusterNodeGroup = new Nodegroup(this, `${props.name}-managed-ng`, {
       amiType: props.amiType,
+      releaseVersion: getReleaseVersion(props.amiType, props.version.version, this),
       instanceTypes: props.instanceTypes,
       cluster: this.cluster,
       minSize: 2,
@@ -48,6 +71,7 @@ export class EC2Stack extends Stack {
         version: lt.latestVersionNumber
       }
     });
+
     clusterNodeGroup.role.addManagedPolicy(
       ManagedPolicy.fromAwsManagedPolicyName('AmazonSSMManagedInstanceCore')
     );