Parameterizing AMI IDs in CloudFormation Templates

Correct Answer: D.

Option A is incorrect because there is no “Fn::FindInParameter” intrinsic function.

It is not how parameters are used in CloudFormation.

To reference a parameter, you need to use the “Ref” intrinsic function.

Option B is incorrect because “Conditions” are used to define different circumstances.

The “Conditions” section is not suitable to define AMI IDs.

Option C is incorrect because the optional “Metadata” section provides details about the template such as descriptions.

It cannot define AMI IDs.

Option D is CORRECT because the “Mappings” section is suitable to create a mapping with key/value pairs.

In this case, the key is the AWS region, and the value is the AMI ID.

The values in the map can be retrieved through the “Fn::FindInMap” function.

Reference:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/mappings-section-structure.html

Sure, I'd be happy to explain the different options for parameterizing the AMI ID in CloudFormation templates for multiple AWS Regions.

First, let's start with some background information. CloudFormation is a service provided by AWS that allows you to define and manage infrastructure as code. With CloudFormation, you can create a collection of AWS resources as a single unit called a stack, which can be easily managed and replicated across multiple AWS Regions.

In this scenario, the system administrator wants to parameterize the AMI ID in the CloudFormation templates so that the same template can be used for different AWS Regions. This means that the AMI ID value can be different depending on which AWS Region the template is being used in. To achieve this, we can use the following options:

Option A: Use the “Parameters” section to define the AMI ID per region and return the correct AMI ID through the “Fn::FindInParameter” intrinsic function.

With this option, we can define a parameter for the AMI ID in the CloudFormation template, and specify a different value for the parameter for each AWS Region. Then, we can use the "Fn::FindInParameter" intrinsic function to retrieve the correct value of the AMI ID based on the region specified. This option is suitable when the number of AWS Regions is small, and the AMI ID values are not likely to change frequently.

Option B: Use “Conditions” to include different AMI IDs per region and return the correct AMI ID through the “Fn::If” intrinsic function.

With this option, we can define a condition for each AWS Region in the CloudFormation template, and specify the AMI ID value for each condition. Then, we can use the "Fn::If" intrinsic function to check the condition for the current AWS Region, and return the corresponding AMI ID value. This option is suitable when the number of AWS Regions is small to medium, and the AMI ID values may change frequently.

Option C: Use “Metadata” to define different AMI IDs per region and return the correct AMI ID through the “Fn::FindInMetadata” intrinsic function.

With this option, we can define the AMI ID values in the CloudFormation template metadata section, and use the "Fn::FindInMetadata" intrinsic function to retrieve the correct value based on the current AWS Region. This option is suitable when the number of AWS Regions is small, and the AMI ID values are not likely to change frequently.

Option D: Use “Mappings” to include different AMI IDs per region and return the correct AMI ID through the “Fn::FindInMap” intrinsic function.

With this option, we can define a mapping for each AWS Region in the CloudFormation template, and specify the AMI ID value for each mapping. Then, we can use the "Fn::FindInMap" intrinsic function to retrieve the correct value based on the current AWS Region. This option is suitable when the number of AWS Regions is large, and the AMI ID values may change frequently.

In summary, the most suitable option for parameterizing the AMI ID in CloudFormation templates for multiple AWS Regions depends on the specific requirements and constraints of the scenario. Option A is suitable when the number of AWS Regions is small, and the AMI ID values are not likely to change frequently. Option B is suitable when the number of AWS Regions is small to medium, and the AMI ID values may change frequently. Option C is suitable when the number of AWS Regions is small, and the AMI ID values are not likely to change frequently. Option D is suitable when the number of AWS Regions is large, and the AMI ID values may change frequently.