I am running this template in cloud formation to create auto scaling in ubuntu-18.04 machine and it will rollback the all instances automatically that is created by this template and giving such error like.
Received 0 SUCCESS signal(s) out of 1. Unable to satisfy 100% MinSuccessfulInstancesPercent requirement The following resource(s) failed to create: [WebServerGroup]. . Rollback requested by user.
{
"AWSTemplateFormatVersion": "2010-09-09",
"Parameters": {
"VpcId": {
"Type": "AWS::EC2::VPC::Id",
"Description": "VpcId of your existing Virtual Private Cloud (VPC)",
"ConstraintDescription": "must be the VPC Id of an existing Virtual Private Cloud."
},
"Subnets": {
"Type": "List<AWS::EC2::Subnet::Id>",
"Description": "The list of SubnetIds in your Virtual Private Cloud (VPC)"
},
"InstanceType": {
"Description": "WebServer EC2 instance type",
"Type": "String",
"Default": "t2.small",
"AllowedValues": [
"t1.micro",
"t2.nano",
"t2.micro",
"t2.small",
"t2.medium",
"t2.large",
"m1.small",
"m1.medium",
"cg1.4xlarge"
],
"ConstraintDescription": "must be a valid EC2 instance type."
},
"WebServerCapacity": {
"Default": "2",
"Description": "The initial number of WebServer instances",
"Type": "Number",
"MinValue": "1",
"MaxValue": "10",
"ConstraintDescription": "must be between 1 and 10 EC2 instances."
},
"KeyName": {
"Description": "The EC2 Key Pair to allow SSH access to the instances",
"Type": "AWS::EC2::KeyPair::KeyName",
"ConstraintDescription": "must be the name of an existing EC2 KeyPair."
},
"SSHLocation": {
"Description": "The IP address range that can be used to SSH to the EC2 instances",
"Type": "String",
"MinLength": "9",
"MaxLength": "18",
"Default": "0.0.0.0/0",
"AllowedPattern": "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})/(\\d{1,2})",
"ConstraintDescription": "must be a valid IP CIDR range of the form x.x.x.x/x."
}
},
"Resources": {
"WebServerScaleUpPolicy": {
"Type": "AWS::AutoScaling::ScalingPolicy",
"Properties": {
"AdjustmentType": "ChangeInCapacity",
"AutoScalingGroupName": {
"Ref": "WebServerGroup"
},
"Cooldown": "60",
"ScalingAdjustment": 1
}
},
"WebServerScaleDownPolicy": {
"Type": "AWS::AutoScaling::ScalingPolicy",
"Properties": {
"AdjustmentType": "ChangeInCapacity",
"AutoScalingGroupName": {
"Ref": "WebServerGroup"
},
"Cooldown": "60",
"ScalingAdjustment": -1
}
},
"CPUAlarmHigh": {
"Type": "AWS::CloudWatch::Alarm",
"Properties": {
"AlarmDescription": "Scale-up if CPU > 70% for 5 minutes",
"MetricName": "CPUUtilization",
"Namespace": "AWS/EC2",
"Statistic": "Average",
"Period": 300,
"EvaluationPeriods": 2,
"Threshold": 70,
"AlarmActions": [{
"Ref": "WebServerScaleUpPolicy"
}],
"Dimensions": [{
"Name": "AutoScalingGroupName",
"Value": {
"Ref": "WebServerGroup"
}
}],
"ComparisonOperator": "GreaterThanThreshold"
}
},
"CPUAlarmLow": {
"Type": "AWS::CloudWatch::Alarm",
"Properties": {
"AlarmDescription": "Scale-down if CPU < 40% for 5 minutes",
"MetricName": "CPUUtilization",
"Namespace": "AWS/EC2",
"Statistic": "Average",
"Period": 300,
"EvaluationPeriods": 2,
"Threshold": 40,
"AlarmActions": [{
"Ref": "WebServerScaleDownPolicy"
}],
"Dimensions": [{
"Name": "AutoScalingGroupName",
"Value": {
"Ref": "WebServerGroup"
}
}],
"ComparisonOperator": "LessThanThreshold"
}
},
"ApplicationLoadBalancer": {
"Type": "AWS::ElasticLoadBalancingV2::LoadBalancer",
"Properties": {
"Name": "elb-test",
"Scheme": "internet-facing",
"IpAddressType": "ipv4",
"Type": "application",
"Subnets": {
"Ref": "Subnets"
}
}
},
"ALBListener": {
"Type": "AWS::ElasticLoadBalancingV2::Listener",
"Properties": {
"DefaultActions": [{
"Type": "forward",
"TargetGroupArn": {
"Ref": "ALBTargetGroup"
}
}],
"LoadBalancerArn": {
"Ref": "ApplicationLoadBalancer"
},
"Port": 80,
"Protocol": "HTTP"
}
},
"ALBTargetGroup": {
"Type": "AWS::ElasticLoadBalancingV2::TargetGroup",
"Properties": {
"Name": "ELB-Group",
"HealthCheckIntervalSeconds": 30,
"HealthCheckTimeoutSeconds": 5,
"HealthyThresholdCount": 3,
"Port": 80,
"Protocol": "HTTP",
"TargetType": "instance",
"UnhealthyThresholdCount": 5,
"VpcId": {
"Ref": "VpcId"
}
}
},
"WebServerGroup": {
"Type": "AWS::AutoScaling::AutoScalingGroup",
"Properties": {
"VPCZoneIdentifier": {
"Ref": "Subnets"
},
"HealthCheckGracePeriod": 300,
"LaunchConfigurationName": {
"Ref": "LaunchConfig"
},
"MinSize": "1",
"MaxSize": "8",
"DesiredCapacity": {
"Ref": "WebServerCapacity"
},
"TargetGroupARNs": [{
"Ref": "ALBTargetGroup"
}]
},
"CreationPolicy": {
"ResourceSignal": {
"Timeout": "PT5M",
"Count": {
"Ref": "WebServerCapacity"
}
}
},
"UpdatePolicy": {
"AutoScalingRollingUpdate": {
"MinInstancesInService": 1,
"MaxBatchSize": 1,
"PauseTime": "PT5M",
"WaitOnResourceSignals": true
}
}
},
"LaunchConfig": {
"Type": "AWS::AutoScaling::LaunchConfiguration",
"Metadata" : {
"Comment" : "Install a simple application",
"AWS::CloudFormation::Init" : {
"full_install" : [ "install_and_enable_cfn_hup" ]
},
"install_and_enable_cfn_hup" : {
"files" : {
"/etc/cfn/cfn-hup.conf" : {
"content" : { "Fn::Join" : ["", [
"[main]\n",
"stack=", { "Ref" : "AWS::StackId" }, "\n",
"region=", { "Ref" : "AWS::Region" }, "\n"
]]},
"mode" : "000400",
"owner" : "root",
"group" : "root"
},
"/etc/cfn/hooks.d/cfn-auto-reloader.conf" : {
"content": { "Fn::Join" : ["", [
"[cfn-auto-reloader-hook]\n",
"triggers=post.update\n",
"path=Resources.EC2Instance.Metadata.AWS::CloudFormation::Init\n",
"action=/opt/aws/bin/cfn-init -v ",
" --stack ", { "Ref" : "AWS::StackName" },
" --resource LaunchConfig",
" --configsets full_install ",
" --region ", { "Ref" : "AWS::Region" }, "\n",
"runas=root\n"
]]}
},
"/lib/systemd/system/cfn-hup.service": {
"content": { "Fn::Join" : ["", [
"[Unit]\n",
"Description=cfn-hup daemon\n\n",
"[Service]\n",
"Type=simple\n",
"ExecStart=/opt/aws/bin/cfn-hup\n",
"Restart=always\n\n",
"[Install]\n",
"WantedBy=multi-user.target"]]}
}
},
"commands" : {
"01enable_cfn_hup" : {
"command" : "systemctl enable cfn-hup.service"
},
"02start_cfn_hup" : {
"command" : "systemctl start cfn-hup.service"
}
}
}
},
"Properties": {
"KeyName": {
"Ref": "KeyName"
},
"ImageId": "ami-00932e4c143f3fdf0",
"SecurityGroups": [{
"Ref": "InstanceSecurityGroup"
}],
"InstanceType": {
"Ref": "InstanceType"
},
"UserData" : { "Fn::Base64" : { "Fn::Join" : ["", [
"#!/bin/bash -xe\n",
"apt-get update -y\n",
"apt-get install -y python-setuptools\n",
"mkdir -p /opt/aws/bin\n",
"python /usr/lib/python2.7/dist-packages/easy_install.py --script-dir /opt/aws/bin https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz\n",
"/opt/aws/bin/cfn-init -v ",
" --stack ", { "Ref" : "AWS::StackName" },
" --resource LaunchConfig",
" --configsets full_install ",
" --region ", { "Ref" : "AWS::Region" }, "\n",
"/opt/aws/bin/cfn-signal -e $? ",
" --stack ", { "Ref" : "AWS::StackName" },
" --resource WebServerGroup",
" --region ", { "Ref" : "AWS::Region" }, "\n"
]]}}}
},
"InstanceSecurityGroup": {
"Type": "AWS::EC2::SecurityGroup",
"Properties": {
"GroupDescription": "Enable SSH access and HTTP from the load balancer only",
"SecurityGroupIngress": [{
"IpProtocol": "tcp",
"FromPort": 22,
"ToPort": 22,
"CidrIp": {
"Ref": "SSHLocation"
}
},
{
"IpProtocol": "tcp",
"FromPort": 80,
"ToPort": 80,
"SourceSecurityGroupId": {
"Fn::Select": [
0,
{
"Fn::GetAtt": [
"ApplicationLoadBalancer",
"SecurityGroups"
]
}
]
}
}
],
"VpcId": {
"Ref": "VpcId"
}
}
}
},
"Outputs": {
"URL": {
"Description": "The URL of the website",
"Value": {
"Fn::Join": [
"",
[
"http://",
{
"Fn::GetAtt": [
"ApplicationLoadBalancer",
"DNSName"
]
}
]
]
}
}
}
}
So please let me know if there is any issue with this template or this CFN command that i am running with this
CreationPolicyandUpdatePolicyto prevent the error you're seeing. With that removed ASG won't expect the signal. With that the instance should boot up and stay up./var/log/cloud-init.logand/var/log/cloud-init-output.log- that will give you a clue what's failing and why it can't send thecfn-signalsuccess back to AWS.Hope that helps :)