Schema syntax reference for CloudFormation Hooks

This section describes the syntax of the schema that you use to develop CloudFormation Hooks.

A Hook includes a Hook specification represented by a JSON schema and Hook handlers. The first step in creating a custom Hook is modeling a schema that defines the Hook, its properties, and their attributes. When you initialize a custom Hook project using the CloudFormation CLI init command, a Hook schema file is created for you. Use this schema file as a starting point for defining the shape and semantics of your custom Hook.

Example Hooks schemas

Example 1

The Java and the Python walkthroughs use the following code example. The following is an example structure for a Hook called mycompany-testing-mytesthook.json.

{
    "typeName":"MyCompany::Testing::MyTestHook",
    "description":"Verifies S3 bucket and SQS queues properties before create and update",
    "sourceUrl":"https://mycorp.com/my-repo.git",
    "documentationUrl":"https://mycorp.com/documentation",
    "typeConfiguration":{
        "properties":{
            "minBuckets":{
                "description":"Minimum number of compliant buckets",
                "type":"string"
            },
            "minQueues":{
                "description":"Minimum number of compliant queues",
                "type":"string"
            },
            "encryptionAlgorithm":{
                "description":"Encryption algorithm for SSE",
                "default":"AES256",
                "type":"string",
                "pattern": "[a-zA-Z]*[1-9]"
            }
        },
        "required":[
            
        ],
        "additionalProperties":false
    },
    "handlers":{
        "preCreate":{
            "targetNames":[
                "AWS::S3::Bucket",
                "AWS::SQS::Queue"
            ],
            "permissions":[
                
            ]
        },
        "preUpdate":{
            "targetNames":[
                "AWS::S3::Bucket",
                "AWS::SQS::Queue"
            ],
            "permissions":[
                
            ]
        },
        "preDelete":{
            "targetNames":[
                "AWS::S3::Bucket",
                "AWS::SQS::Queue"
            ],
            "permissions":[
                "s3:ListBucket",
                "s3:ListAllMyBuckets",
                "s3:GetEncryptionConfiguration",
                "sqs:ListQueues",
                "sqs:GetQueueAttributes",
                "sqs:GetQueueUrl"
            ]
        }
    },
    "additionalProperties":false
}

Example 2

The following example is a schema that uses the STACK and CHANGE_SET for targetNames to target a stack template and a change set operation.

{
    "typeName":"MyCompany::Testing::MyTestHook",
    "description":"Verifies Stack and Change Set properties before create and update",
    "sourceUrl":"https://mycorp.com/my-repo.git",
    "documentationUrl":"https://mycorp.com/documentation",
    "typeConfiguration":{
        "properties":{
            "minBuckets":{
                "description":"Minimum number of compliant buckets",
                "type":"string"
            },
            "minQueues":{
                "description":"Minimum number of compliant queues",
                "type":"string"
            },
            "encryptionAlgorithm":{
                "description":"Encryption algorithm for SSE",
                "default":"AES256",
                "type":"string",
                "pattern": "[a-zA-Z]*[1-9]"
            }
        },
        "required":[
        ],
        "additionalProperties":false
    },
    "handlers":{
        "preCreate":{
            "targetNames":[
                "STACK",
                "CHANGE_SET"
            ],
            "permissions":[  
            ]
        },
        "preUpdate":{
            "targetNames":[
                "STACK"
            ],
            "permissions":[
            ]
        },
        "preDelete":{
            "targetNames":[
                "STACK"
            ],
            "permissions":[
                
            ]
        }
    },
    "additionalProperties":false
}