Nesting and Existing Stack
Nested Stacks are created as a part of other stack
To create Nested Stacks the resource ‘AWS::CloudFormation::Stack’
will be used
Scenario: You already have cloud formation template written to create vpc and if you want to reuse that template rather than rewriting the script every time use nested stacks
Write a reusable template and upload to s3 bucket
Use this s3 buckets url in your current template
{
"AWSTemplateFormatVersion": "2010-09-09",
"Resources": {
"mys3": {
"Type": "AWS::S3::Bucket",
"Properties": {
"AccessControl": "PublicRead",
"BucketName": "testings3qt.com"
}
},
"NestedStack": {
"Type": "AWS::CloudFormation::Stack",
"DeletionPolicy": "Retain",
"Properties": {
"TemplateURL": "https://s3-us-west-2.amazonaws.com/cf-templates-1sv6xf2hjs8h8-us-west-2/2020150aju-common.json",
"Parameters": {
"cidrrange": "10.10.0.0/16"
}
}
}
}
}
Look into DeletionPolicy over here
Exercise: Findout a solution to fetch the details about nested stack other ref
Calling AWS Cloudformation from CLI
AWS CLI Installation and configuration Refer Here
Create a folder cf create a file called as common.json with your cf script
{
"AWSTemplateFormatVersion": "2010-09-09",
"Parameters": {
"cidrrange": {
"Type": "String",
"Default": "192.168.0.0/16"
}
},
"Resources": {
"commonvpc": {
"Type": "AWS::EC2::VPC",
"Properties": {
"CidrBlock": {
"Ref": "cidrrange"
}
}
}
},
"Outputs": {
"vpcid": {
"Value": {
"Ref": "commonvpc"
}
}
}
}
To run this from cli, you need to create stack
cd cf\
aws cloudformation create-stack --stack-name fromcli --template-body file://common.json --parameters ParameterKey=cidrrange,ParameterValue=192.168.0.0/16
To describe stacks status
aws cloudformation describe-stacks --stack-name fromcli
now make changes in your template and update the stack
aws cloudformation update-stack --stack-name fromcli --template-body file://common.json --parameters ParameterKey=cidrrange,ParameterValue=192.168.0.0/16
aws cloudformation delete-stack --stack-name fromcli
Stack Sets
Next Steps
