cf-notify.json

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "cf notify stack",
    "Parameters": {
        "Bucket": {
            "Description": "S3 bucket to locate lambda function (cf-notify.zip)",
            "Type": "String"
        }
    },
    "Resources": {
        "CFNotifyRole": {
            "Type": "AWS::IAM::Role",
            "Properties": {
                "AssumeRolePolicyDocument": {
                    "Version": "2012-10-17",
                    "Statement": [
                        {
                            "Effect": "Allow",
                            "Principal": {
                                "Service": [ "lambda.amazonaws.com" ]
                            },
                            "Action": [ "sts:AssumeRole" ]
                        }
                    ]
                },
                "Path": "/",
                "Policies": [
                    {
                        "PolicyName": "CFNotifyPolicy",
                        "PolicyDocument": {
                            "Version": "2012-10-17",
                            "Statement": [
                                {
                                    "Effect": "Allow",
                                    "Action": [
                                        "logs:CreateLogGroup",
                                        "logs:CreateLogStream",
                                        "logs:PutLogEvents"
                                    ],
                                    "Resource": "arn:aws:logs:*:*:*"
                                },
                                {
                                    "Effect": "Allow",
                                    "Action": [
                                        "cloudformation:DescribeStackResources"
                                    ],
                                    "Resource": "arn:aws:cloudformation:*:*:*/*/*"
                                }
                            ]
                        }
                    }
                ]
            }
        },
        "CFNotifyTopic": {
            "Type": "AWS::SNS::Topic",
            "Properties": {
                "Subscription": [
                    {
                        "Endpoint": { "Fn::GetAtt": [ "CFNotifyFunction", "Arn" ] },
                        "Protocol": "lambda"
                    }
                ]
            }
        },
        "CFNotifyFunction": {
            "Type": "AWS::Lambda::Function",
            "Properties": {
                "Description" : "Lambda function to post CF updates to Slack",
                "Handler": "lambda_notify.lambda_handler",
                "Role": {
                    "Fn::GetAtt": [ "CFNotifyRole", "Arn" ]
                },
                "Code": {
                    "S3Bucket": { "Ref": "Bucket" },
                    "S3Key": "cf-notify.zip"
                },
                "Runtime": "python2.7",
                "Timeout": "30"
            }
        },
        "CFNotifyInvokePermission": {
            "Type": "AWS::Lambda::Permission",
            "Properties": {
                "FunctionName" : { "Ref" : "CFNotifyFunction" },
                "Action": "lambda:InvokeFunction",
                "Principal": "sns.amazonaws.com",
                "SourceArn": { "Ref": "CFNotifyTopic" }
            }
        }
    },
    "Outputs": {
        "CFNotifyEventSource": {
            "Description": "ARN of CF SNS Topic",
            "Value": { "Ref": "CFNotifyTopic" }
        }
    }
}