Add function's EphemeralStorage update support (#73)

Description of changes:
- Add function's EphemeralStorage update support
- Add e2e tests

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Author: Vandita2020

pkg/resource/function/hooks.go

@@ -238,6 +238,15 @@ func (rm *resourceManager) updateFunctionConfiguration(
 		input.VpcConfig = VPCConfig
 	}
 
+	if delta.DifferentAt("Spec.EphemeralStorage") {
+		ephemeralStorage := &svcsdk.EphemeralStorage{}
+		if dspec.EphemeralStorage != nil {
+			ephemeralStorageCopy := dspec.EphemeralStorage.DeepCopy()
+			ephemeralStorage.Size = ephemeralStorageCopy.Size
+		}
+		input.EphemeralStorage = ephemeralStorage
+	}
+
 	_, err = rm.sdkapi.UpdateFunctionConfigurationWithContext(ctx, input)
 	rm.metrics.RecordAPICall("UPDATE", "UpdateFunctionConfiguration", err)
 	if err != nil {

test/e2e/tests/test_function.py

@@ -332,7 +332,7 @@ def test_function_package_type_image(self, lambda_client):
         assert lambda_validator.function_exists(resource_name)
 
         cr["spec"]["timeout"] = 10
-        cr["spec"]["ephemeralStorage"] = { "size" : 512 }
+        cr["spec"]["ephemeralStorage"] = { "size" : 1024 }
 
         # Patch k8s resource
         k8s.patch_custom_resource(ref, cr)
@@ -341,7 +341,7 @@ def test_function_package_type_image(self, lambda_client):
         # Check function updated fields
         function = lambda_validator.get_function(resource_name)
         assert function["Configuration"]["Timeout"] == 10
-        assert function["Configuration"]["EphemeralStorage"]["Size"] == 512
+        assert function["Configuration"]["EphemeralStorage"]["Size"] == 1024
 
         # Delete k8s resource
         _, deleted = k8s.delete_custom_resource(ref)