explain the parameters

Author: gojko

example/template.yml

@@ -6,29 +6,55 @@ Resources:
   TargetBucket:
     Type: AWS::S3::Bucket
 
+  # this function is used only during deployment, 
+  # enabling cloudformation to pack up the web site source and assets
+  # using the standard cloudformation package process
   SiteSource:
     Type: AWS::Serverless::Function
     Properties:
       Layers: 
+        # the layer contains the deployment code 
+        # so the function "source" can just contain the web assets
         - arn:aws:lambda:us-east-1:145266761615:layer:s3-deployment:1
+      # point to directory with the assets so cloudformation can
+      # package and upload them
       CodeUri: web-site/
+      # really important: this will ensure that any change in 
+      # the bundled files gets deployed again. we're abusing
+      # the custom resource pipeline here, so this will be used
+      # to change parameters of the resource and re-trigger it
       AutoPublishAlias: live
+      # the following two lines are required to make the layer work
       Runtime: python3.6 
       Handler: deployer.resource_handler
+      # set the timeout to something reasonable depending on
+      # how long it takes to upload your assets to S3
       Timeout: 600
+      # give the function access to the bucket where it
+      # will upload the assets
       Policies:
       - S3CrudPolicy:
           BucketName: !Ref TargetBucket
 
+  # This is a custom resource that
+  # will trigger the function during deployment
   DeploymentResource:
     Type: AWS::CloudFormation::CustomResource
     Properties:
+      # the following two lines are requires to 
+      # ensure that cloudformation will trigger the
+      # resource every time you change the bundled files
       ServiceToken: !GetAtt SiteSource.Arn
-      TargetBucket: !Ref TargetBucket
-      Acl: 'private'
-      CacheControlMaxAge: 700
       Version: !Ref "SiteSource.Version"
+      # tell the deployer where to upload the files
+      TargetBucket: !Ref TargetBucket
+      # Choose the ACL and caching policies
+      # eg, for directly accessible web site
+      # use public-read and 10 minutes caching
+      Acl: 'public-read'
+      CacheControlMaxAge: 600
+
 
 Outputs:
   DestinationBucket:
-    Value: !Ref TargetBucket
+    Value: !Ref TargetBucket