Merge pull request #546 from guardian/aa/scaling

feat: Add scripts to trigger ASG scale in/out events

README.md

@@ -10,10 +10,12 @@ That is, CDK Playground offers a low risk environment to experiment with.
 The CDK stack is defined in the [cdk](./cdk) directory.
 
 There are a couple of helpful scripts in the [script](./script) directory:
-  1. `./script/start-play` to run the Play app
-  1. `./script/start-cdk` to start Jest in watch mode, to test the CDK stack
-  1. `./script/build-cdk` to synthesise the CDK stack into a template
-  1. `./script/switch-cdk` to install GuCDK from a GitHub branch. This is useful to test changes _without_ publishing to NPM first.
+1. `./script/start-play` to run the Play app
+2. `./script/start-cdk` to start Jest in watch mode, to test the CDK stack
+3. `./script/build-cdk` to synthesise the CDK stack into a template
+4. `./script/switch-cdk` to install GuCDK from a GitHub branch. This is useful to test changes _without_ publishing to NPM first.
+5. `./script/scale-out` to simulate a scale out event, increasing the capacity of the autoscaling group
+6. `./script/scale-in` to simulate a scale in event, decreasing the capacity of the autoscaling group
 
 ## Deploying
 The app is set up in the usual way, with CI on each branch (via GitHub Actions) and [CD](https://riffraff.gutools.co.uk/deployment/history?projectName=devx%3A%3Acdk-playground&stage=PROD&pageSize=20&page=1) on `main`.

cdk/lib/__snapshots__/cdk-playground.test.ts.snap

@@ -32,6 +32,11 @@ Object {
     "gu:cdk:version": "TEST",
   },
   "Outputs": Object {
+    "AutoscalingGroupName": Object {
+      "Value": Object {
+        "Ref": "AutoScalingGroupCdkplaygroundASGD6E49F0F",
+      },
+    },
     "LoadBalancerCdkplaygroundDnsName": Object {
       "Description": "DNS entry for LoadBalancerCdkplayground",
       "Value": Object {
@@ -41,6 +46,22 @@ Object {
         ],
       },
     },
+    "ScaleInArn": Object {
+      "Value": Object {
+        "Fn::GetAtt": Array [
+          "AutoScalingGroupCdkplaygroundScaleIn24F0C6B8",
+          "Arn",
+        ],
+      },
+    },
+    "ScaleOutArn": Object {
+      "Value": Object {
+        "Fn::GetAtt": Array [
+          "AutoScalingGroupCdkplaygroundScaleOutA06BF2EE",
+          "Arn",
+        ],
+      },
+    },
     "lambdacdkplaygroundlambdaapiEndpoint0E1DFC5F": Object {
       "Value": Object {
         "Fn::Join": Array [
@@ -79,6 +100,11 @@ Object {
       "Description": "SSM parameter containing the Name (not ARN) on the kinesis stream",
       "Type": "AWS::SSM::Parameter::Value<String>",
     },
+    "MinInstancesInServiceForcdkplayground": Object {
+      "Default": 1,
+      "MaxValue": 9,
+      "Type": "Number",
+    },
     "VpcId": Object {
       "Default": "/account/vpc/primary/id",
       "Description": "Virtual Private Cloud to run EC2 instances within. Should NOT be the account default VPC.",
@@ -138,7 +164,6 @@ Object {
         "AsgRollingUpdatePolicy2A1DDC6F",
       ],
       "Properties": Object {
-        "DesiredCapacity": "1",
         "HealthCheckGracePeriod": 120,
         "HealthCheckType": "ELB",
         "LaunchTemplate": Object {
@@ -152,7 +177,7 @@ Object {
             ],
           },
         },
-        "MaxSize": "2",
+        "MaxSize": "10",
         "MetricsCollection": Array [
           Object {
             "Granularity": "1Minute",
@@ -210,8 +235,10 @@ Object {
       "Type": "AWS::AutoScaling::AutoScalingGroup",
       "UpdatePolicy": Object {
         "AutoScalingRollingUpdate": Object {
-          "MaxBatchSize": 2,
-          "MinInstancesInService": 1,
+          "MaxBatchSize": 10,
+          "MinInstancesInService": Object {
+            "Ref": "MinInstancesInServiceForcdkplayground",
+          },
           "MinSuccessfulInstancesPercent": 100,
           "PauseTime": "PT3M",
           "SuspendProcesses": Array [
@@ -221,6 +248,28 @@ Object {
         },
       },
     },
+    "AutoScalingGroupCdkplaygroundScaleIn24F0C6B8": Object {
+      "Properties": Object {
+        "AdjustmentType": "ChangeInCapacity",
+        "AutoScalingGroupName": Object {
+          "Ref": "AutoScalingGroupCdkplaygroundASGD6E49F0F",
+        },
+        "PolicyType": "SimpleScaling",
+        "ScalingAdjustment": -1,
+      },
+      "Type": "AWS::AutoScaling::ScalingPolicy",
+    },
+    "AutoScalingGroupCdkplaygroundScaleOutA06BF2EE": Object {
+      "Properties": Object {
+        "AdjustmentType": "ChangeInCapacity",
+        "AutoScalingGroupName": Object {
+          "Ref": "AutoScalingGroupCdkplaygroundASGD6E49F0F",
+        },
+        "PolicyType": "SimpleScaling",
+        "ScalingAdjustment": 1,
+      },
+      "Type": "AWS::AutoScaling::ScalingPolicy",
+    },
     "CertificateCdkplayground47FCF7D9": Object {
       "DeletionPolicy": "Retain",
       "Properties": Object {

cdk/lib/cdk-playground.ts

@@ -6,7 +6,8 @@ import { GuStack } from '@guardian/cdk/lib/constructs/core';
 import { GuCname } from '@guardian/cdk/lib/constructs/dns';
 import { GuEc2AppExperimental } from '@guardian/cdk/lib/experimental/patterns/ec2-app';
 import type { App } from 'aws-cdk-lib';
-import { Duration } from 'aws-cdk-lib';
+import { CfnOutput, Duration } from 'aws-cdk-lib';
+import { CfnScalingPolicy } from 'aws-cdk-lib/aws-autoscaling';
 import { InstanceClass, InstanceSize, InstanceType } from 'aws-cdk-lib/aws-ec2';
 import { Runtime } from 'aws-cdk-lib/aws-lambda';
 
@@ -35,7 +36,7 @@ export class CdkPlayground extends GuStack {
 		const ec2App = 'cdk-playground';
 		const ec2AppDomainName = 'cdk-playground.gutools.co.uk';
 
-		const { loadBalancer } = new GuEc2AppExperimental(this, {
+		const { loadBalancer, autoScalingGroup } = new GuEc2AppExperimental(this, {
 			buildIdentifier,
 			applicationPort: 9000,
 			app: ec2App,
@@ -53,7 +54,7 @@ export class CdkPlayground extends GuStack {
 			monitoringConfiguration: { noMonitoring: true },
 			scaling: {
 				minimumInstances: 1,
-				maximumInstances: 2,
+				maximumInstances: 10,
 			},
 			applicationLogging: {
 				enabled: true,
@@ -62,6 +63,35 @@ export class CdkPlayground extends GuStack {
 			imageRecipe: 'developerPlayground-arm64-java11',
 		});
 
+		const scaleOutPolicy = new CfnScalingPolicy(autoScalingGroup, 'ScaleOut', {
+			autoScalingGroupName: autoScalingGroup.autoScalingGroupName,
+			policyType: 'SimpleScaling',
+			adjustmentType: 'ChangeInCapacity',
+			scalingAdjustment: 1,
+		});
+
+		const scaleInPolicy = new CfnScalingPolicy(autoScalingGroup, 'ScaleIn', {
+			autoScalingGroupName: autoScalingGroup.autoScalingGroupName,
+			policyType: 'SimpleScaling',
+			adjustmentType: 'ChangeInCapacity',
+			scalingAdjustment: -1,
+		});
+
+		new CfnOutput(this, 'ScaleOutArn', {
+			key: 'ScaleOutArn',
+			value: scaleOutPolicy.attrArn,
+		});
+
+		new CfnOutput(this, 'ScaleInArn', {
+			key: 'ScaleInArn',
+			value: scaleInPolicy.attrArn,
+		});
+
+		new CfnOutput(this, 'AutoscalingGroupName', {
+			key: 'AutoscalingGroupName',
+			value: autoScalingGroup.autoScalingGroupName,
+		});
+
 		new GuCname(this, 'EC2AppDNS', {
 			app: ec2App,
 			ttl: Duration.hours(1),

script/scale-in

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+
+set -e
+
+CLOUDFORMATION_STACK_NAME=playground-PROD-cdk-playground
+
+POLICY_ARN=$(
+  aws cloudformation describe-stacks \
+      --stack-name "$CLOUDFORMATION_STACK_NAME" \
+      --profile developerPlayground \
+      --region eu-west-1 \
+      --no-cli-pager | \
+      jq -r '.Stacks[].Outputs[] | select( [.OutputKey | contains("ScaleInArn") ] | any) | .OutputValue'
+)
+
+ASG_NAME=$(
+  aws cloudformation describe-stacks \
+      --stack-name "$CLOUDFORMATION_STACK_NAME" \
+      --profile developerPlayground \
+      --region eu-west-1 \
+      --no-cli-pager | \
+      jq -r '.Stacks[].Outputs[] | select( [.OutputKey | contains("AutoscalingGroupName") ] | any) | .OutputValue'
+)
+
+CURRENT_DESIRED_CAPACITY=$(
+  aws autoscaling describe-auto-scaling-groups \
+    --auto-scaling-group-names "$ASG_NAME" \
+    --profile developerPlayground \
+    --region eu-west-1 | \
+    jq -r '.AutoScalingGroups[].DesiredCapacity'
+)
+
+aws autoscaling execute-policy \
+  --policy-name "$POLICY_ARN" \
+  --profile developerPlayground \
+  --region eu-west-1
+
+NEW_DESIRED_CAPACITY=$(
+  aws autoscaling describe-auto-scaling-groups \
+    --auto-scaling-group-names "$ASG_NAME" \
+    --profile developerPlayground \
+    --region eu-west-1 | \
+    jq -r '.AutoScalingGroups[].DesiredCapacity'
+)
+
+echo "Desired capacity has been updated from $CURRENT_DESIRED_CAPACITY to $NEW_DESIRED_CAPACITY"

script/scale-out

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+
+set -e
+
+CLOUDFORMATION_STACK_NAME=playground-CODE-scaling-asg-rolling-update
+
+POLICY_ARN=$(
+  aws cloudformation describe-stacks \
+      --stack-name "$CLOUDFORMATION_STACK_NAME" \
+      --profile developerPlayground \
+      --region eu-west-1 \
+      --no-cli-pager | \
+      jq -r '.Stacks[].Outputs[] | select( [.OutputKey | contains("ScaleOutArn") ] | any) | .OutputValue'
+)
+
+ASG_NAME=$(
+  aws cloudformation describe-stacks \
+      --stack-name "$CLOUDFORMATION_STACK_NAME" \
+      --profile developerPlayground \
+      --region eu-west-1 \
+      --no-cli-pager | \
+      jq -r '.Stacks[].Outputs[] | select( [.OutputKey | contains("AutoscalingGroupName") ] | any) | .OutputValue'
+)
+
+CURRENT_DESIRED_CAPACITY=$(
+  aws autoscaling describe-auto-scaling-groups \
+    --auto-scaling-group-names "$ASG_NAME" \
+    --profile developerPlayground \
+    --region eu-west-1 | \
+    jq -r '.AutoScalingGroups[].DesiredCapacity'
+)
+
+aws autoscaling execute-policy \
+  --policy-name "$POLICY_ARN" \
+  --profile developerPlayground \
+  --region eu-west-1
+
+NEW_DESIRED_CAPACITY=$(
+  aws autoscaling describe-auto-scaling-groups \
+    --auto-scaling-group-names "$ASG_NAME" \
+    --profile developerPlayground \
+    --region eu-west-1 | \
+    jq -r '.AutoScalingGroups[].DesiredCapacity'
+)
+
+echo "Desired capacity has been updated from $CURRENT_DESIRED_CAPACITY to $NEW_DESIRED_CAPACITY"