Support Serverless Application Model (SAM) templates

[skatsuta]

CloudFormation supports Serverless Application Model (SAM) templates, but when we use a SAM template StackMaster returns the following error:

$ stack_master apply
...
...
No stack found
Create stack (y/n)?
Uploading files to S3:
...
Aws::CloudFormation::Errors::ValidationError CreateStack cannot be used with templates containing Transforms.

This is because CreateStack API does not support SAM templates.
Instead, we need to use a change set to create a SAM-based stack.
So it'd be great if StackMaster supports SAM templates.

[skatsuta]

Blocker is #177.

[skatsuta]

Merging both #178 and #179 will support this feature.

[patrobinson]

I've released verison 0.16.0 which includes the above PRs

[skatsuta]

Great! I confirmed the version works fine with SAM. Thank you for your support!

[tanyajajodia]

Hi @skatsuta - Does StackMaster support the aws cloudformation package step as well for SAM templates?

I get the following error when I try to create a stack directly using stack_master apply:
Transform AWS::Serverless-2016-10-31 failed with: Invalid Serverless Application Specification document. Number of errors found: 1. Resource with id [GraphQL] is invalid. 'CodeUri' is not a valid S3 Uri of the form "s3://bucket/key" with optional versionId query parameter.

[patrobinson]

@tanyajajodia sorry for the late reply. No we don't currently support that step, it must be done before StackMaster is invoked.
I'd be happy to include such functionality in the future, at present we are just using plain old SAM, but it'd be nice to directly integrate it with StackMaster.