isabella232 / pcc-sample-app-pizzastore

Example sample application which uses Pivotal Cloud Cache(PCC) as a service on Pivotal Cloud Foundry

Sample Spring Boot Application for VMware Tanzu GemFire

This versioned example app for VMware Tanzu GemFire is a Spring Boot app that can be used with a Tanzu GemFire service instance. That service instance may be configured either with or without TLS encryption enabled.

The app uses Spring Boot Data Geode (SBDG) to talk to the Tanzu GemFire service instance. The app provides a REST interface that lets a user view pizzas, place orders, and view an order. The app leverages Spring Web MVC controllers to expose data access operations.

Pizzas are stored in the Tanzu GemFire servers running within the Tanzu GemFire service instance. The app uses Spring Data Repositories to store, access, and query data stored on the servers. The app stores data in two repositories Pizza and Name (repositories are referred to as regions in Tanzu GemFire). See GemFire Basics for the briefest of introductions to Tanzu GemFire, and see Region Design for a quick tour of Tanzu GemFire regions.

This app performs operations on two regions:

• The Pizza region represents the pizzas on order. Each pizza has a unique name used as the key for the region entry. The value portion of the key/value entry is the specification of a sauce and any toppings on a single pizza.
• The Name region is populated by the unique name associated with the pizzas with pesto as a sauce. A Tanzu GemFire continuous query triggers a put to the Name region whenever a pizza with pesto sauce is added. See Continuous Querying for an extensive explanation of Tanzu GemFire continuous queries.

Pizza sauces are one of:

• ALFREDO
• BARBECUE
• HUMMUS
• MARINARA
• PESTO
• TAPENADE
• TOMATO

Pizza toppings are any of:

• ARUGULA
• BACON
• BANANA_PEPPERS
• BLACK_OLIVES
• CHEESE
• CHERRY_TOMATOES
• CHICKEN
• GREEN_OLIVES
• GREEN_PEPPERS
• JALAPENO
• MUSHROOM
• ONIONS
• PARMESAN
• PEPPERONI
• SAUSAGE

Prepare to Run the Pizza App

The app runs with a Tanzu GemFire service instance. This app is versioned, and branches of this git repository correspond to the Tanzu GemFire version that this app will work with. Check out and run the app from the branch that matches your Tanzu GemFire tile version. For example, if your Tanzu GemFire service instance is version 1.11, check out this repository's release/1.11 branch. This is important because the procedure to run the app differs slightly, based on whether TLS encryption is enabled or not. Follow the appropriate setup procedure.

Prerequisites

1. You should be logged in to your cf environment. Please see cf login
2. The CF environment should have a Tanzu Gemfire Tile installed.

Prepare with TLS Communication

1. Create the Tanzu GemFire service instance with TLS enabled:

   $ cf create-service p-cloudcache PLAN_NAME SERVICE_INSTANCE -c '{"tls":true}'
   

   Note the name of your SERVICE_INSTANCE, as it will be used in the manifest.yml file.

2. Create the regions required by the app using gfsh:

   Connect to the cluster via gfsh. Please see Accessing a Service Instance for detailed instructions on connecting to your service instance.

   gfsh>create region --name=Pizza --type=REPLICATE
   gfsh>create region --name=Name --type=REPLICATE
   

3. Configure the app to use SSL by adding this property to src/main/resources/application.properties:

   spring.data.gemfire.security.ssl.use-default-context=true
   

4. Modify the manifest.yml file such that the service instance is no longer commented out and has the name of your Tanzu GemFire service instance. If your service instance had the name dev-instance-1, then the services portion of the manifest.yml file would be:

     services:
      - dev-instance-1
   

Prepare Without TLS Communication

The Spring Boot framework detects whether the service instance has TLS enabled or not, so the same manifest is used when pushing the app as is shown above.

1. Create a Tanzu GemFire service instance without enabling TLS encryption:

   cf create-service p-cloudcache PLAN_NAME SERVICE_INSTANCE
   

   Note the name of your SERVICE_INSTANCE, as it will be used in the manifest.yml file.

2. Create the regions required by the app using gfsh:

   Connect to the cluster. See Accessing a Service Instance for detailed instructions on connecting to your service instance.

   gfsh>create region --name=Pizza --type=REPLICATE
   gfsh>create region --name=Name --type=REPLICATE
   

3. Modify the manifest.yml file such that the service instance is no longer commented out and has the name of your Tanzu GemFire service instance. If your service instance had the name dev-instance-1, then the services portion of the manifest.yml file would be:

     services:
      - dev-instance-1
   

Build and Run the Pizza App

Build and cf push the app. With current working directory of PCC-Sample-App-PizzaStore:

$ ./mvnw clean install
$ cf push

REST API endpoints

All REST API endpoints are accessible using HTTP GET. This is not very RESTful, but is convenient when accessing this app from your web browser.

Run the command:

$ cf apps

to acquire your app's APP-URL. Use the APP-URL with the following endpoints:

• GET /ping

  Responds with an HTTP status code of 200 - OK and an HTTP message body of "PONG!" if the app is running correctly.

  $ curl -k https://APP-URL/ping
  

• GET /preheatOven

  Loads the Pizza region with three pre-defined pizzas. This REST API endpoint calls Repository.save() for each pizza and verifies the pizzas with the Repository.findById(..) on the Pizza region to verify that everything was set up properly. It creates these pizzas:

  1. tomato sauce and a cheese topping
  2. Alfredo sauce, and chicken and arugula toppings
  3. pesto sauce, and chicken, cherry tomatoes and parmesan cheese toppings

  Responds with an HTTP message body of "OVEN HEATED!".

  $ curl -k https://APP-URL/preheatOven
  

• GET /pizzas

  Lists the current contents of the Pizza region, formatted as a JSON array containing Pizza objects. Returns "No Pizzas Found" if the region is empty.

  $ curl -k https://APP-URL/pizzas
  

• GET /pizzas/{name}

  Returns the pizza with the specified name. Returned pizza is in JSON form. Returns "Pizza [name] Not Found" if no pizza with the given name exists.

  curl -k https://APP-URL/pizzas/plain
  

• GET /pizzas/order/{name}\[?sauce=<sauce>\[&toppings=\<topping-1>,\<topping-2>,...,\<topping-N>]]

  Adds a pizza order for the specified name, with an optional sauce (defaults to TOMATO) and optional toppings (defaults to CHEESE). Changes the pizza order if the name is already present in the pizzas on order.

  curl -k https://APP-URL/pizzas/order/myCustomPizza?sauce=MARINARA&toppings=CHEESE,PEPPERONI,MUSHROOM
  

• GET /pizzas/pestoOrder/{name}

  Bakes a pesto sauce pizza with chicken, cherry tomatoes, and parmesan cheese toppings.

  curl -k https://APP-URL/pizzas/pestoOrder/myPestoPizza
  

• GET /cleanSlate

  Removes all data from the Pizza and Name regions.

  $  curl -k https://APP-URL/cleanSlate
  

Continuous Queries

A Tanzu GemFire Continuous Query allows an app to register interest in events. Interest is expressed with an OQL query on regions containing the data interests. This is ideal, since a developer can specify complex criteria in an OQL query predicate for the exact data the app is interested in receiving notifications for. Thus, when a data event occurs matching the conditions expressed in the query predicate, an event will be returned with the data.

This Spring Boot app registers two continuous queries on the Pizza region.

• Whenever any pizza is ordered, the event is logged to System.err.

• When any pesto pizza is ordered, the event triggers putting the name of the pizza in the Name region.

For more details, see the Tanzu GemFire documentation section on Continuous Querying.

For more details on how to use continuous queries in your Spring Boot apps see Configuring Continuous Queries.