Add comments to output

Author: dpoirier

stack/__init__.py

@@ -1,3 +1,4 @@
+import datetime
 import os
 
 from . import sftp  # noqa: F401
@@ -30,4 +31,13 @@
 # Must be last to tag all resources
 from . import tags  # noqa: F401
 
+# Since we're outputting YAML, we can include comments
+print("# This Cloudformation stack template was generated by")
+print("# https://github.com/caktus/aws-web-stacks")
+print("# at %s" % datetime.datetime.now())
+print("# with parameters:")
+use_parms = sorted(parm for parm in os.environ.keys() if parm.startswith("USE_"))
+for parm in use_parms:
+    print("#\t%s = %s" % (parm, os.environ[parm]))
+print()
 print(template.template.to_yaml())