cfn-init指定自定义json

Question

Is there a way to tell cfn-init to use a custom JSON file loaded from disk? That way I can quickly troubleshoot problems, otherwise the only way to change the AWS::CloudFormation::Init section is to delete the stack and create it anew.

I'd rather just make changes to my template.json , then tell something like cfn-init -f C:\\template.json ... so it uses C:\\template.json instead of getting the template from 169.254.169.254 or however it gets it.

Answer 1

Turns out cfn-init does accept a file, but the file needs to have the "Metadata" key as the root key.

So if we save this to template.json :

{
    "AWS::CloudFormation::Init": {
        "config": {
            "files": {
                "C:\\Users\\Administrator\\Desktop\\test-file": {
                    "source": "https://s3.us-east-2.amazonaws.com/example-bucket/example-file"
                }
            }
        }
    },
    "AWS::CloudFormation::Authentication": {
        "S3AccessCreds": {
            "type": "S3",
            "buckets": ["example-bucket"],
            "roleName": "s3access"
        }
    }
}

Then we can execute cfn-init -v --region us-east-2 template.json .

Note: Do not include the stack or resource, if you use cfn-init -v -s my_stack -r my_instance --region us-east-2 template.json you will get:

Error: You cannot specify more than one input source for metadata

If you put the entire template file instead of just "Metadata" as root, you will get:

Could not find 'AWS::CloudFormation::Init' key in template.json