Minimum Python >= 3.7, drop oyaml, add support for short intrinsic AWS functions

CHANGES.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.9.7
+- CloudBender now requires Python >= 3.7
+- drop oyaml requirement
+- support for short intrinsic functions like !Ref, !Sub etc. by ignoring custom constructors before sending them to AWS to resolve
+
 ## 0.9.6
 - only upload templates if render is successful
 - support for jinja user-data

cloudbender/__init__.py

@@ -2,7 +2,7 @@ import logging
 
 __author__ = "Stefan Reimer"
 __email__ = "stefan@zero-downtimet.net"
-__version__ = "0.9.6"
+__version__ = "0.9.7"
 
 
 # Set up logging to ``/dev/null`` like a library is supposed to.

cloudbender/stack.py

@@ -1,7 +1,7 @@
 import os
 import re
 import hashlib
-import oyaml as yaml
+import yaml
 import time
 import pathlib
 import pprint
@@ -32,6 +32,15 @@ import logging
 logger = logging.getLogger(__name__)
 
 
+# Ignore any !<Constructors> during re-loading of CFN templates
+class SafeLoaderIgnoreUnknown(yaml.SafeLoader):
+    def ignore_unknown(self, node):
+        return node.tag
+
+
+SafeLoaderIgnoreUnknown.add_constructor(None, SafeLoaderIgnoreUnknown.ignore_unknown)
+
+
 class Stack(object):
     def __init__(self, name, template, path, rel_path, ctx):
         self.stackname = name
@@ -135,7 +144,7 @@ class Stack(object):
 
         try:
             self.cfn_template = template.render(_config)
-            self.cfn_data = yaml.safe_load(self.cfn_template)
+            self.cfn_data = yaml.load(self.cfn_template, Loader=SafeLoaderIgnoreUnknown)
         except Exception as e:
             # In case we rendered invalid yaml this helps to debug
             if self.cfn_template:
@@ -184,7 +193,7 @@ class Stack(object):
             logger.info("Piped mode: Added parameters for remote stack references")
 
         # Re-read updated template
-        self.cfn_data = yaml.safe_load(self.cfn_template)
+        self.cfn_data = yaml.load(self.cfn_template, Loader=SafeLoaderIgnoreUnknown)
 
         # Check for empty top level Parameters, Outputs and Conditions and remove
         for key in ['Parameters', 'Outputs', 'Conditions']:
@@ -318,7 +327,7 @@ class Stack(object):
                     logger.warn("Could not find template file: {}".format(yaml_file))
                     raise e
 
-            self.cfn_data = yaml.safe_load(self.cfn_template)
+            self.cfn_data = yaml.load(self.cfn_template, Loader=SafeLoaderIgnoreUnknown)
             self._parse_metadata()
         else:
             logger.debug('Using cached cfn template %s.', self.stackname)

dev-requirements.txt

@@ -1,6 +1,5 @@
 boto3
 Jinja2
-oyaml
 click
 pyminifier
 cfn-lint

requirements.txt

@@ -1,6 +1,5 @@
 boto3
 Jinja2
-oyaml
 click
 pyminifier
 cfn-lint>=0.34

setup.py

@@ -47,6 +47,7 @@ setup(
     name='cloudbender',
     version=find_version("cloudbender/__init__.py"),
     description='Toolset to render and manage AWS Cloudformation',
+    python_requires='>=3.7',
     long_description=long_description,
     long_description_content_type="text/markdown",
     author='Stefan Reimer',
@@ -56,7 +57,7 @@ setup(
     package_data={ 'cloudbender': ['templates/*.md'], },
     include_package_data=True,
     entry_points={'console_scripts': [ "cloudbender = cloudbender.cli:cli" ]},
-    install_requires=['boto3', 'Jinja2', 'oyaml', 'click', 'cfn-lint>=0.34', 'pyminifier'],
+    install_requires=['boto3', 'Jinja2', 'click', 'cfn-lint>=0.34', 'pyminifier'],
     tests_require=["pytest-cov", "moto", "mock", 'pytest'],
     cmdclass={"test": PyTest},
     classifiers=[