AWS Cloudformation : Passing environmental variables as parameters to lambda functions

Question

I am creating a cloud formation for lambda . I want to have a generic lambda script that created lambda . I am having problem injecting "Environment" parameter from outside .

I want to pass the key value pair object as parameter . Can some one tell me how to do it . I have highlighted it below

{
  "Variables" : **{ String:String, ... }**
}

{
  "Type" : "AWS::Lambda::Function",
  "Properties" : {
    "Code" : Code,
    "DeadLetterConfig" : DeadLetterConfig,
    "Description" : String,
    "Environment" : Environment,
    "FunctionName" : String,
    "Handler" : String,
    "KmsKeyArn" : String,
    "MemorySize" : Integer,
    "ReservedConcurrentExecutions" : Integer,
    "Role" : String,
    "Runtime" : String,
    "Timeout" : Integer,
    "TracingConfig" : TracingConfig,
    "VpcConfig" : VPCConfig,
    "Tags" : [ Resource Tag, ... ]
  }
}

Solution 1

For this purpose there is special section in cloudformation template - Parameters

"Parameters" : {
  "MyVariable" : {
    "Type" : "String",
    "Default" : "test",
    "AllowedValues" : ["test", "non-test"],
    "Description" : "My very important variable."
  }
}

And then use these parameters in Function declaration:

"Environment":{  
   "Variables":{  
      "SomeVariable":{  
         "Ref":"MyVariable"
      }
   }
}

And then pass values for this Parameters block when creating stack from cloudformation template:

aws cloudformation create-stack --stack-name S1 --template-body example template --parameters ParameterKey=MyVariable,ParameterValue=myValue

More information - here

Solution 2

"I want to pass the key value pair object as parameter"
You cannot pass key-value pairs as parameters in AWS CF templates. For the accepted parameter types please see this