Add Suspended Processes to an Autoscaling Group with Cloudformation - aws-cloudformation

Question

I need to add suspended processes to Cloudformation.
I tried adding a SuspendedProcesses property.
ASG:
Type: AWS::AutoScaling::AutoScalingGroup
Properties:
DesiredCapacity: 1
MinSize: 1
MaxSize: 2
LaunchConfigurationName: !Ref LaunchConfigurationName
SuspendedProcesses:
- ReplaceUnhealthy
However, I receive an error that it's an unsupported property.

Answer 1

You can create a Lambda function to modify the ASG as it it being created using a CustomResource. This also needs an IAM::Role, as the Lambda function needs a reference to one as part of its definition.
credit to https://gist.github.com/atward/9573b9fbd3bfd6c453158c28356bec05 for most of this:
ASG:
Type: AWS::AutoScaling::AutoScalingGroup
Properties:
DesiredCapacity: 1
MinSize: 1
MaxSize: 2
LaunchConfigurationName: !Ref LaunchConfigurationName
AsgProcessModificationRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Action:
- sts:AssumeRole
Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Policies:
- PolicyName: AsgProcessModification
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action:
- autoscaling:ResumeProcesses
- autoscaling:SuspendProcesses
Resource: "*"
- Effect: Allow
Action:
- logs:CreateLogGroup
- logs:CreateLogStream
- logs:PutLogEvents
Resource: arn:aws:logs:*:*:*
AsgProcessModifierFunction:
Type: AWS::Lambda::Function
Properties:
Description: Modifies ASG processes during CF stack creation
Code:
ZipFile: |
import cfnresponse
import boto3
def handler(event, context):
props = event['ResourceProperties']
client = boto3.client('autoscaling')
try:
response = client.suspend_processes(AutoScalingGroupName=props['AutoScalingGroupName'], 'ReplaceUnhealthy'])
cfnresponse.send(event, context, cfnresponse.SUCCESS, {})
except Exception as e:
cfnresponse.send(event, context, cfnresponse.FAILED, {})
Handler: index.handler
Role:
Fn::GetAtt:
- AsgProcessModificationRole
- Arn
Runtime: python2.7
ModifyAsg:
Type: AWS::CloudFormation::CustomResource
Version: 1
Properties:
ServiceToken:
Fn::GetAtt:
- AsgProcessModifierFunction
- Arn
AutoScalingGroupName:
Ref: ASG
ScalingProcesses:
- ReplaceUnhealthy

Answer 2

You can add an UpdatePolicy attribute to your AutoScaleGroup to control this.
AWS has some documentation on this here:
https://aws.amazon.com/premiumsupport/knowledge-center/auto-scaling-group-rolling-updates/
Here is a sample adding in SuspendProcesses:
ASG:
Type: AWS::AutoScaling::AutoScalingGroup
UpdatePolicy:
AutoScalingRollingUpdate:
SuspendProcesses:
- "ReplaceUnhealthy"
Properties:
DesiredCapacity: 1
MinSize: 1
MaxSize: 2
LaunchConfigurationName: !Ref LaunchConfigurationName
Full information on using the UpdatePolicy attribute is available here:
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-updatepolicy.html#cfn-attributes-updatepolicy-rollingupdate-maxbatchsize

Answer 3

if you are using aws CDK, the following should work
const autoscaling = require('#aws-cdk/aws-autoscaling');
const custom_resource = require('#aws-cdk/custom-resources');
function stopAsgScaling(stack, asgName) {
return new custom_resource.AwsCustomResource(stack, 'MyAwsCustomResource', {
policy: custom_resource.AwsCustomResourcePolicy.fromSdkCalls({
resources: custom_resource.AwsCustomResourcePolicy.ANY_RESOURCE
}),
onCreate: {
service: 'AutoScaling',
action: 'suspendProcesses',
parameters: {
AutoScalingGroupName: asgName,
},
physicalResourceId: custom_resource.PhysicalResourceId.of(
'InvokeLambdaResourceId1234'),
},
onDelete: {
service: 'AutoScaling',
action: 'resumeProcesses',
parameters: {
AutoScalingGroupName: asgName,
},
physicalResourceId: custom_resource.PhysicalResourceId.of(
'InvokeLambdaResourceId1234'),
},
})
};
class MainStack extends cdk.Stack {
constructor(scope, id, props) {
super(scope, id, props);
const autoScalingGroupName = "my-asg"
const myAsg = new autoscaling.AutoScalingGroup(
this,
autoScalingGroupName,
{autoScalingGroupName: autoScalingGroupName})
const acr = stopAsgScaling(this, autoScalingGroupName);
acr.node.addDependency(myAsg);
}
};