cloudformation resources reference

1. How do you reference existing resources in CloudFormation?
2. What does REF mean in CloudFormation?
3. How do you reference a parameter in CloudFormation?
4. How do you reference output in CloudFormation?
5. Does CloudFormation override existing resources?
6. What is CloudFormation?
7. Does ref return Arn?
8. What is parameter CloudFormation?
9. How are variables used in CloudFormation?
10. What are the main components of CloudFormation?
11. What is a parameter in AWS?
12. What is metadata in CloudFormation?

How do you reference existing resources in CloudFormation?

Existing resources can be referenced in CDK by calling the Construct's fromXXX() method. They often need ARNs or Ids which can be imported from existing CloudFormation Stacks. Just Vpc. fromLookup() is a special case as it reads the values from your AWS account during cdk synth and stores them in 'cdk.

What does REF mean in CloudFormation?

Filter View. The intrinsic function Ref returns the value of the specified parameter or resource. When you specify a parameter's logical name, it returns the value of the parameter. When you specify a resource's logical name, it returns a value that you can typically use to refer to that resource, such as a physical ID ...

How do you reference a parameter in CloudFormation?

Referencing a parameter within a template

You use the Ref intrinsic function to reference a parameter, and AWS CloudFormation uses the parameter's value to provision the stack. You can reference parameters from the Resources and Outputs sections of the same template.

How do you reference output in CloudFormation?

To create a cross-stack reference, use the export field to flag the value of a resource output for export. Then, use the Fn::ImportValue intrinsic function to import the value in any stack within the same AWS Region and account. AWS CloudFormation identifies exported values by the names specified in the template.

Does CloudFormation override existing resources?

Replacement. AWS CloudFormation recreates the resource during an update, which also generates a new physical ID. AWS CloudFormation usually creates the replacement resource first, changes references from other dependent resources to point to the replacement resource, and then deletes the old resource.

What is CloudFormation?

RSS. AWS CloudFormation is a service that helps you model and set up your Amazon Web Services resources so that you can spend less time managing those resources and more time focusing on your applications that run in AWS.

Does ref return Arn?

Ref is used to reference other resources or parameters in your template. Depending on the Resource it will return what data is typically needed the most from that resource. For example for a S3 Bucket it returns the bucket name, for an ACM Certificate it will return the ARN.

What is parameter CloudFormation?

Parameter types enable CloudFormation to validate inputs earlier in the stack creation process. For example in the past if you entered an invalid key pair, you would have to wait until CloudFormation attempted to create the Amazon EC2 instance to see the problem.

How are variables used in CloudFormation?

A string with variables that AWS CloudFormation substitutes with their associated values at runtime. Write variables as $ MyVarName . Variables can be template parameter names, resource logical IDs, resource attributes, or a variable in a key-value map.

What are the main components of CloudFormation?

CloudFormation templates are JSON or YAML-formatted text files comprised of five types of elements:

• An optional list of template parameters (input values supplied at stack creation time)
• An optional list of output values (e.g., the complete URL to a web application)

What is a parameter in AWS?

Parameter Store is an AWS service that stores strings. It can store secret data and non-secret data alike. Secrets stored in Parameter Store are secure strings, encrypted with a customer-specific AWS KMS key. ... The ECS task requests its secrets from Parameter Store using the task role credentials.

What is metadata in CloudFormation?

What's the purpose of the Metadata section in a CloudFormation Template? amazon-web-services amazon-cloudformation. AWS describes the overall CloudFormation Template anatomy in this doc. It states that the Metadata section is a JSON object that provides additional information about the template.