S3 TemplateURLs transformed to local file path

[1davidmichael]

Description

sam build transforms TemplateURL from S3 https link to local file path. The example provided is a basic CFN template to show the output but have seen this on full SAM templates with SAM resources as well.

Steps to reproduce

Run sam build with the following example template:

---
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A test CFN template

Resources:
  ExampleNestedStack:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: https://s3.amazonaws.com/examplebucket/exampletemplate.yml

Observed result

$ sam build --debug
Telemetry endpoint configured to be https://aws-serverless-tools-telemetry.us-west-2.amazonaws.com/metrics
'build' command is called
No Parameters detected in the template
1 resources found in the template

Build Succeeded

Built Artifacts  : .aws-sam/build
Built Template   : .aws-sam/build/template.yaml

Commands you can use next
=========================
[*] Invoke Function: sam local invoke
[*] Deploy: sam deploy --guided

Sending Telemetry: {'metrics': [{'commandRun': {'awsProfileProvided': False, 'debugFlagProvided': True, 'region': '', 'commandName': 'sam build', 'duration': 141, 'exitReason': 'success', 'exitCode': 0, 'requestId': 'a878c824-f550-4eae-8528-56d1d0595c2d', 'installationId': '320f3374-6b5d-450f-9735-ce91d16a517f', 'sessionId': '787a2613-5ee8-4d71-9ba5-0520625027b6', 'executionEnvironment': 'CLI', 'pyversion': '3.7.6', 'samcliVersion': '0.43.0'}}]}

Note that template URL is transformed to TemplateURL: ../../https:/s3.amazonaws.com/examplebucket/exampletemplate.yml in the output template in .aws-sam/build/template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A test CFN template
Resources:
  ExampleNestedStack:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: ../../https:/s3.amazonaws.com/examplebucket/exampletemplate.yml

Expected result

Expect TemplateURL for S3 paths remains untouched. Example:

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A test CFN template
Resources:
  ExampleNestedStack:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: https://s3.amazonaws.com/examplebucket/exampletemplate.yml

Additional environment details (Ex: Windows, Mac, Amazon Linux etc)

1. OS: Amazon Linux 2 Linux ip-10-255-156-170.ec2.internal 4.14.165-131.185.amzn2.x86_64 #1 SMP Wed Jan 15 14:19:56 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
2. sam --version: SAM CLI, version 0.43.0 Installed via https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install-linux.html instructions

[jfuss]

@1davidmichael O that is interesting... Thanks for the report. Updating labels.

[jfuss]

Released in v0.46.0.

Closing

[1davidmichael]

Thanks!

[kirstenkissmeyer]

Hi there,
I am using sam cli version 1.21.1. I am encountering this same issue for sam deploy. The S3 https templateURL is getting prepended with the local path from which I am running sam deploy on an Amazon Linux 2 t3.small instance. Similar steps to reproduce for nested stack yaml...
Kirsten