In this recipe, we used the following CloudFormation template components: Resource, AWSTemplateFormatVersion, and Description. Resources are the AWS resources used in the template. AWSTemplateFormatVersion is the version of CloudFormation template the template conforms to. 

We used two resources: a role (IAMRoleLambdaExecution) and a Lambda function (LambdaFunctionWithCF) that depends on that role. Resource names can be anything. Type specifies the type of the resource. We used two types, namely AWS::IAM::Role and AWS::Lambda::Function.

The properties of the AWS::IAM::Role resource type that we used are as follows:

• AssumeRolePolicyDocument specifies the trust relationship policy for the role
• Policies specify the policies inline

The properties of the AWS::Lambda::Function resource type that we used are as follows:

• Code property specifies the S3 bucket and the key. You can also specify a reference to an S3 Bucket resource type so that a new bucket is created dynamically and its name is used here.
• FunctionName specifies the name of the Lambda function.
• Handler specifies the fully qualified name of the handler class with the handler method.
• MemorySize specifies the memory in MB. The number of CPU cores is decided by AWS based on the memory.
• Role specifies the role. 
• Runtime specifies the runtime (for instance, java8).
• TimeOut specifies the timeout. 

To get the role Arn, we used the GetAtt function passing the logical name of the Role and the property name Arn:

Fn::GetAtt is an intrinsic function that returns the value of an attribute from a resource in the template. 

We used CloudFormation designer in the recipe to see our template in design view, and then uploaded the template into a stack from the designer. You can also use the Designer to design CloudFormation templates from scratch.