Adds Callback functions and docs

README.md

@@ -164,6 +164,11 @@ to change Zappa's behavior. Use these at your own risk!
         "assume_policy": "my_assume_policy.json", // optional, IAM assume policy JSON file
         "attach_policy": "my_attach_policy.json", // optional, IAM attach policy JSON file
         "aws_region": "us-east-1", // AWS Region (default US East),
+        "callbacks": { // Call custom functions during the Zappa deployment/update process
+            "settings": "my_app.settings_callback", // After loading the settings
+            "zip": "my_app.zip_callback", // After creating the package
+            "post": "my_app.post_callback", // After command has excuted
+        },
         "cache_cluster_enabled": false, // Use APIGW cache cluster (default False)
         "cache_cluster_size": .5, // APIGW Cache Cluster size (default 0.5)
         "debug": true // Print Zappa configuration errors tracebacks in the 500

test_settings.json

@@ -2,6 +2,11 @@
     "ttt888": {
        "s3_bucket": "lmbda",
        "app_function": "tests.test_app.hello_world",
+       "callbacks": {
+           "settings": "test_settings.callback",
+           "post": "test_settings.callback",
+           "zip": "test_settings.callback"
+       },
        "delete_zip": true,
        "debug": true,
        "parameter_depth": 2, 

test_settings.py

@@ -17,3 +17,6 @@
 
 def prebuild_me():
     print("This is a prebuild script!")
+
+def callback(self):
+    print("this is a callback")

tests/tests.py

@@ -455,9 +455,11 @@ def test_human_units(self):
         zappa.human_size(9999999999999)
 
     def test_detect_dj(self):
+        # Sanity
         settings_modules = detect_django_settings()
 
     def test_detect_flask(self):
+        # Sanity
         settings_modules = detect_flask_apps()
 
 if __name__ == '__main__':

zappa/cli.py

@@ -16,6 +16,7 @@
 import hjson as json
 import inspect
 import imp
+import importlib
 import logging
 import os
 import pkg_resources
@@ -148,6 +149,8 @@ def handle(self, argv=None):
 
             # Load our settings
             self.load_settings(vargs['settings_file'])
+            self.callback('settings')
+
             if vargs['app_function'] is not None:
                 self.app_function = vargs['app_function']
 
@@ -202,6 +205,7 @@ def deploy(self):
 
         # Create the Lambda Zip
         self.create_package()
+        self.callback('zip')
 
         # Upload it to S3
         success = self.zappa.upload_to_s3(
@@ -250,6 +254,8 @@ def deploy(self):
         # Remove the uploaded zip from S3, because it is now registered..
         self.zappa.remove_from_s3(self.zip_path, self.s3_bucket_name)
 
+        self.callback('post')
+
         print("Deployed! {}".format(endpoint_url))
 
 
@@ -267,6 +273,7 @@ def update(self):
 
         # Create the Lambda Zip,
         self.create_package()
+        self.callback('zip')
 
         # Upload it to S3
         success = self.zappa.upload_to_s3(self.zip_path, self.s3_bucket_name)
@@ -295,6 +302,8 @@ def update(self):
         else:
             endpoint_url = self.zappa.get_api_url(self.lambda_name, self.api_stage)
 
+        self.callback('post')
+
         print("Your updated Zappa deployment is live! {}".format(endpoint_url))
 
         return
@@ -599,6 +608,21 @@ def init(self, settings_file="zappa_settings.json"):
     # Utility
     ##
 
+    def callback(self, position):
+        """
+        Allows the execution of custom code between creation of the zip file and deployment to AWS.
+
+        :return: None
+        """
+        callbacks = self.zappa_settings[self.api_stage].get('callbacks', {})
+        callback = callbacks.get(position)
+
+        if callback:
+            (mod_name, cb_func) = callback.rsplit('.', 1)
+
+            module_ = importlib.import_module(mod_name)
+            getattr(module_, cb_func)(self)  # Call the function passing self
+
     def load_settings(self, settings_file="zappa_settings.json", session=None):
         """
         Load the local zappa_settings.json file.
@@ -766,7 +790,6 @@ def create_package(self):
                 temp_settings.close()
                 lambda_zip.write(temp_settings.name, 'zappa_settings.py')
                 os.remove(temp_settings.name)
-                # lambda_zip.close()
 
     def remove_local_zip(self):
         """