added some pre-actionable checks for update and read handler to align… (#294)

Author: ammokhov

python/rpdk/java/templates/init/guided_aws/StubDeleteHandler.java

@@ -56,7 +56,7 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
                     // STEP 1.3 [TODO: handle exception]
                     .handleError((awsRequest, exception, client, model, context) -> {
                         // TODO: uncomment when ready to implement
-                        // if (exception instanceof CfnNotFoundException)
+                        // if (exception instanceof ResourceNotFoundException)
                         //     return ProgressEvent.success(model, context);
                         // throw exception;
                         return ProgressEvent.progress(model, context);
@@ -105,6 +105,10 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
                         logger.log(String.format("%s [%s] deletion has stabilized: %s", ResourceModel.TYPE_NAME, model.getPrimaryIdentifier(), stabilized));
                         return stabilized;
                     })
-                    .success());
+                    .progress()
+            )
+
+            // STEP 3 [TODO: return the successful progress event without resource model]
+            .then(progress -> ProgressEvent.defaultSuccessHandler(null));
     }
 }

python/rpdk/java/templates/init/guided_aws/StubHandlerTest.java

@@ -60,7 +60,11 @@ public void handleRequest_SimpleSuccess() {
         assertThat(response).isNotNull();
         assertThat(response.getStatus()).isEqualTo(OperationStatus.SUCCESS);
         assertThat(response.getCallbackDelaySeconds()).isEqualTo(0);
+        {% if operation == "Delete" %}
+        assertThat(response.getResourceModel()).isNull();
+        {% else %}
         assertThat(response.getResourceModel()).isEqualTo(request.getDesiredResourceState());
+        {% endif %}
         assertThat(response.getResourceModels()).isNull();
         assertThat(response.getMessage()).isNull();
         assertThat(response.getErrorCode()).isNull();

python/rpdk/java/templates/init/guided_aws/StubReadHandler.java

@@ -42,6 +42,8 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
                 try {
 
                     // TODO: add custom read resource logic
+                    // If describe request does not return ResourceNotFoundException, you must throw ResourceNotFoundException based on
+                    // awsResponse values
 
                 } catch (final AwsServiceException e) { // ResourceNotFoundException
                     /*

python/rpdk/java/templates/init/guided_aws/StubUpdateHandler.java

@@ -29,17 +29,45 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
         // https://github.com/aws-cloudformation/cloudformation-cli-java-plugin/blob/master/src/main/java/software/amazon/cloudformation/proxy/CallChain.java
 
         return ProgressEvent.progress(request.getDesiredResourceState(), callbackContext)
-            // STEP 1 [first update/stabilize progress chain - required for resource update]
+
+            // STEP 1 [check if resource already exists]
+            // for more information -> https://docs.aws.amazon.com/cloudformation-cli/latest/userguide/resource-type-test-contract.html
+            // if target API does not support 'ResourceNotFoundException' then following check is required
             .then(progress ->
                 // STEP 1.0 [initialize a proxy context]
+                // If your service API does not return ResourceNotFoundException on update requests against some identifier (e.g; resource Name)
+                // and instead returns a 200 even though a resource does not exist, you must first check if the resource exists here
+                // NOTE: If your service API throws 'ResourceNotFoundException' for update requests this method is not necessary
+                proxy.initiate("{{ call_graph }}::{{ operation }}::PreUpdateCheck", proxyClient, progress.getResourceModel(), progress.getCallbackContext())
+
+                    // STEP 1.1 [initialize a proxy context]
+                    .translateToServiceRequest(Translator::translateToReadRequest)
+
+                    // STEP 1.2 [TODO: make an api call]
+                    .makeServiceCall((awsRequest, client) -> {
+                        AwsResponse awsResponse = null;
+
+                        // TODO: add custom read resource logic
+                        // If describe request does not return ResourceNotFoundException, you must throw ResourceNotFoundException based on
+                        // awsResponse values
+
+                        logger.log(String.format("%s has successfully been read.", ResourceModel.TYPE_NAME));
+                        return awsResponse;
+                    })
+                    .progress()
+            )
+
+            // STEP 2 [first update/stabilize progress chain - required for resource update]
+            .then(progress ->
+                // STEP 2.0 [initialize a proxy context]
                 // Implement client invocation of the update request through the proxyClient, which is already initialised with
                 // caller credentials, correct region and retry settings
                 proxy.initiate("{{ call_graph }}::{{ operation }}::first", proxyClient, progress.getResourceModel(), progress.getCallbackContext())
 
-                    // STEP 1.1 [TODO: construct a body of a request]
+                    // STEP 2.1 [TODO: construct a body of a request]
                     .translateToServiceRequest(Translator::translateToFirstUpdateRequest)
 
-                    // STEP 1.2 [TODO: make an api call]
+                    // STEP 2.2 [TODO: make an api call]
                     .makeServiceCall((awsRequest, client) -> {
                         AwsResponse awsResponse = null;
                         try {
@@ -60,7 +88,7 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
                         return awsResponse;
                     })
 
-                    // STEP 1.3 [TODO: stabilize step is not necessarily required but typically involves describing the resource until it is in a certain status, though it can take many forms]
+                    // STEP 2.3 [TODO: stabilize step is not necessarily required but typically involves describing the resource until it is in a certain status, though it can take many forms]
                     // stabilization step may or may not be needed after each API call
                     // for more information -> https://docs.aws.amazon.com/cloudformation-cli/latest/userguide/resource-type-test-contract.html
                     .stabilize((awsRequest, awsResponse, client, model, context) -> {
@@ -74,17 +102,17 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
                     .progress())
 
             // If your resource is provisioned through multiple API calls, then the following pattern is required (and might take as many postUpdate callbacks as necessary)
-            // STEP 2 [second update/stabilize progress chain]
+            // STEP 3 [second update/stabilize progress chain]
             .then(progress ->
-                    // STEP 2.0 [initialize a proxy context]
+                    // STEP 3.0 [initialize a proxy context]
                     // If your resource is provisioned through multiple API calls, you will need to apply each subsequent update
                     // step in a discrete call/stabilize chain to ensure the entire resource is provisioned as intended.
                     proxy.initiate("{{ call_graph }}::{{ operation }}::second", proxyClient, progress.getResourceModel(), progress.getCallbackContext())
 
-                    // STEP 2.1 [TODO: construct a body of a request]
+                    // STEP 3.1 [TODO: construct a body of a request]
                     .translateToServiceRequest(Translator::translateToSecondUpdateRequest)
 
-                    // STEP 2.2 [TODO: make an api call]
+                    // STEP 3.2 [TODO: make an api call]
                     .makeServiceCall((awsRequest, client) -> {
                         AwsResponse awsResponse = null;
                         try {
@@ -106,7 +134,7 @@ protected ProgressEvent<ResourceModel, CallbackContext> handleRequest(
                     })
                     .progress())
 
-            // STEP 3 [TODO: describe call/chain to return the resource model]
+            // STEP 4 [TODO: describe call/chain to return the resource model]
             .then(progress -> new ReadHandler().handleRequest(proxy, request, callbackContext, proxyClient, logger));
     }
 }