Getting error while validating aws cloud formation - aws-cloudformation

Question

I am trying to learn and practise AWS Cloudformation template.
While validating the template i am getting below error.
$ aws cloudformation validate-template --template-body file:///home/bhemanth/Downloads/ec2-templates/singe-instance-v2.yaml
An error occurred (ValidationError) when calling the ValidateTemplate operation: Invalid template resource property 'BlockDeviceMappings'
CloudFormation Template Code Error:
AWSTemplateFormatVersion: '2010-09-09'
Description: 'CentOS EC2 Instance template'
Parameters:
KeyName:
Description: Name of an existing EC2 KeyPair to enable SSH access to the instance
Type: AWS::EC2::KeyPair::KeyName
Default: hemanth
AllowedValues:
- hemanth
- client
ConstraintDescription: must be the name of an existing EC2 KeyPair.
InstanceType:
Description: CentOS
Type: String
Default: t2.small
AllowedValues:
- t2.micro
- t2.small
- t2.medium
ConstraintDescription: must be a valid EC2 instance type.
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:
EC2Instance:
Type: AWS::EC2::Instance
Properties:
InstanceType:
Ref: InstanceType
SecurityGroups:
- Ref: InstanceSecurityGroup
KeyName:
Ref: KeyName
ImageId: ami-01ed306a12b7d1c96
InstanceSecurityGroup:
Type: AWS::EC2::SecurityGroup
Properties:
GroupName: EnableAll
GroupDescription: Enable SSH access for all ports
SecurityGroupIngress:
- IpProtocol: tcp
FromPort: '0'
ToPort: '65535'
CidrIp:
Ref: SSHLocation
BlockDeviceMappings:
- DeviceName: /dev/sda1
Ebs:
DeleteOnTermination: true
Status: attached
Hypervisor: xen
RootDeviceName: /dev/sda1
RootDeviceType: ebs
Tags:
- Key: Name
Value: Docker
VirtualizationType: hvm
UserData:
Fn::Base64: !Sub |
#!/usr/bin/env bash
yum install -y wget
wget -O- https://get.docker.com/ | sh
systemctl status docker
systemctl start docker
systemctl enable docker
systemctl status docker
systemctl status -l docker
Volumes:
- Attachments:
Device: /dev/sda1
State: attached
DeleteOnTermination: true
AvailabilityZone: us-west-2a
Encrypted: false
Size: 30
State: in-use
Iops: 100
VolumeType: gp2
Outputs:
InstanceId:
Description: InstanceId of the newly created EC2 instance
Value:
Ref: EC2Instance
AZ:
Description: Availability Zone of the newly created EC2 instance
Value:
Fn::GetAtt:
- EC2Instance
- AvailabilityZone
PublicDNS:
Description: Public DNSName of the newly created EC2 instance
Value:
Fn::GetAtt:
- EC2Instance
- PublicDnsName
PublicIP:
Description: Public IP address of the newly created EC2 instance
Value:
Fn::GetAtt:
- EC2Instance
- PublicIp
I am trying to prepare aws cloudformation template which will install docker from userdata and delete the volume when instance is terminated.
Can you please advice what is wrong in my template.
If possible can you please good tips and cheats for creating aws cloudformation for beginners.
Thanks,
Hemanth.

Answer 1

The CloudFormation Linter catches this and more with:
E3001 Invalid resource attribute BlockDeviceMappings for resource InstanceSecurityGroup
singe-instance-v2.yaml:51:5
E3001 Invalid resource attribute Hypervisor for resource InstanceSecurityGroup
singe-instance-v2.yaml:56:5
E3001 Invalid resource attribute RootDeviceName for resource InstanceSecurityGroup
singe-instance-v2.yaml:57:5
E3001 Invalid resource attribute RootDeviceType for resource InstanceSecurityGroup
singe-instance-v2.yaml:58:5
E3001 Invalid resource attribute Tags for resource InstanceSecurityGroup
singe-instance-v2.yaml:59:5
E3001 Invalid resource attribute VirtualizationType for resource InstanceSecurityGroup
singe-instance-v2.yaml:62:5
E3001 Invalid resource attribute UserData for resource InstanceSecurityGroup
singe-instance-v2.yaml:63:5
E3001 Invalid resource attribute Volumes for resource InstanceSecurityGroup
singe-instance-v2.yaml:73:5
Property types like BlockDeviceMappings, Tags, UserData, Volumes, and AvailabilityZone should be indented a level further than Properties:
I also believe those properties should be underneath Properties: in the AWS::EC2::Instance resource, because most of them are not valid property types of AWS::EC2::SecurityGroup
I don't think Hypervisor is a valid property type of any resource type, so I'm not sure where that property type came from
I'd recommend referencing the documentation for the AWS::EC2::SecurityGroup and AWS::EC2::Instance resource types