Cloud Foundry Tutorial for Application Development

Cloud Foundry is a popular platform for developing and deploying applications in the cloud. It provides a flexible and scalable environment for building, testing, and running applications.

Cloud Foundry supports a wide range of programming languages, including Java, Python, and Node.js. This makes it an ideal choice for developers who work with multiple languages.

With Cloud Foundry, you can easily deploy applications to the cloud and manage them through a user-friendly web interface. This interface provides real-time monitoring and logging capabilities, making it easier to debug and troubleshoot issues.

Cloud Foundry also provides a robust security framework that includes features such as authentication, authorization, and encryption.

Cloud Foundry is an open-source platform as a service (PaaS) that allows you to deploy and manage applications in the cloud.

First, you'll need to sign up for a Cloud Foundry account, which can be done on the Cloud Foundry website.

Cloud Foundry supports a wide range of programming languages, including Java, Python, and Node.js.

Download the Cloud Foundry CLI (Command Line Interface) tool, which is available for Windows, macOS, and Linux.

The CLI tool allows you to deploy and manage your applications from the command line.

You can also use the Cloud Foundry web interface to deploy and manage your applications, but the CLI tool is generally faster and more convenient.

Cloud Foundry is an open-source platform as a service (PaaS) that provides a choice of cloud, developer frameworks, and application services. It's governed by the Cloud Foundry Foundation.

Cloud Foundry is developed by Pivotal, a joint venture company by GE, EMC, and VMware. The original Cloud Foundry was developed by VMware.

Cloud Foundry is free to use, and you can sign up for a free account on the Pivotal website to start deploying your applications.

Here are some certified providers of Cloud Foundry:

Cloud platforms like Cloud Foundry let you deploy network apps or services in a few minutes, and they scale automatically to handle more traffic as your app becomes popular.

In Cloud Foundry, applications are represented by microservices, each with its own Cloud Foundry application. These microservices must be run within a single Cloud Foundry Space.

You need to use the following scheme for Cloud Foundry hosts: {appName}-{tenantName} in Cloud Foundry Manifest files.

To deploy an application to Cloud Foundry, you need to run a cf push command from the Cloud Foundry Command Line Interface (cf CLI). This command will perform several tasks, including uploading and storing the application files, examining and storing app metadata, creating a droplet for the application, selecting an appropriate Diego cell to run the droplet, and starting the application.

Here are the tasks performed by Cloud Foundry when you deploy an application:

Applications that use services, such as a database, messaging, or email server, are not fully functional until you provision the service and, if required, bind the service to the applications.

Distributing apps is a crucial step in deploying your application on Cloud Foundry. Cloud Foundry includes the stack, which is the operating system the app runs on, and the buildpack, which contains all languages, libraries, and services that the app uses.

To ensure your app is portable, it must be able to run on multiple host VMs with everything needed to compile and run locally. Cloud Foundry stages your app for delivery by combining the stack, buildpack, and source code into a droplet that the VM can unpack, compile, and run.

Here's a breakdown of the components included in your app's source code:

For simple, standalone apps, the droplet can contain a pre-compiled executable instead of source code, language, and libraries. This makes deployment faster and more efficient.

Backing Services are any services your app may consume over the network as part of its normal operation. This can include data stores like PostgreSQL, messaging and queuing systems like RabbitMQ, and logging services.

Some examples of Backing Services include data stores, messaging and queuing systems, caching systems, and logging services. These services can be described as factories that produce Service Instances based on Service Plans.

To incorporate Backing Services into your app, you'll need to write a Service Broker, which manages the life cycle of the service. This involves using the Service Broker API to advertise a catalog of service offerings to Cloud Foundry apps.

A Service Broker uses the Service Broker API to advertise a catalog of service offerings to Cloud Foundry apps. This allows apps to discover and use the services they need.

Here's a breakdown of the typical steps involved in using services with your apps on Cloud Foundry:

By following these steps, you can incorporate Backing Services into your app and make the most of the services they offer.

The App Router Gateway is a crucial component in managing applications. It acts as a single point-of-entry gateway to route requests to.

The App Router ensures user login and authentication in combination with XSUAA. This means that users need to be authenticated before they can access your application.

There are two types of App Routers: Managed App Router and Custom App Router. The Managed App Router is provided by SAP Fiori Launchpad for SAP Build Work Zone, and the Custom App Router needs to be deployed along with your application.

To use the Managed App Router, you need to configure it in mta.yaml and on each SAP Fiori application. For the Custom App Router, you can use the command "shcds add approuter" to enhance the application configuration.

Here are the different types of App Routers:

Learn more about the SAP BTP Application Router to get a deeper understanding of how it works.

To deploy an application to Cloud Foundry, you need to run a cf push command from the Cloud Foundry Command Line Interface (cf CLI). This command will perform several tasks, including uploading and storing the application files, examining and storing app metadata, creating a droplet, selecting an appropriate Diego cell, and starting the application.

If your application uses services, such as a database or email server, it will not be fully functional until you provision the service and bind it to the application.

Cloud Foundry supports applications that consist of one or more microservices, and each microservice is represented by a Cloud Foundry application, which must be run within a single Cloud Foundry Space.

Creating a Spring Boot application is a straightforward process. We'll create one and deploy it to the PWS console and access it from Cloud Foundry itself.

To create a Spring Boot application, we'll follow a simple approach. We'll expose one simple REST endpoint, which we'll test from our workstation once deployed in Pivotal Web Service Platform.

The application will be created using the Spring Boot framework. This framework provides a lot of built-in features that make application development easier.

We'll use the Spring Boot Application to create a REST endpoint. This endpoint will be used to test the application once it's deployed.

To add a REST controller, you'll need to open the Spring Boot application class, which is SpringHelloworldCfApplication.java by default. The automated project generation provides this class.

You'll need to add some lines to this class to create a simple REST endpoint. This endpoint will echo something based on the input.

The final class will look like the example provided in the article.

Buildpacks are a crucial part of Cloud Foundry, and they're what make it possible to deploy applications with ease. They provide a framework and runtime support for applications, and they automatically detect the buildpack for your application when you push it.

You can also specify the buildpack explicitly in the Cloud Foundry Manifest, which gives you more control over the deployment process. Cloud Foundry currently supports a wide range of buildpacks, including Java, Node.js, and .NET Core.

Here are some of the buildpacks that Cloud Foundry currently supports:

By using buildpacks, you can ensure that your application is properly configured and deployed, and you can focus on writing code rather than worrying about the underlying infrastructure.

Compute Resources are a crucial aspect of Application Development in Cloud Foundry. Cloud Foundry utilizes multiple virtual machines to provide an environment for executing applications.

Memory consumption is the most important metric for computing resources in Cloud Foundry. This is because every application runs within a container and it's not possible to assign a specific CPU to an application.

Orgs represent a complete organization, like a company, while Spaces are an environment for a number of micro services that form an application. Applications run a process with a specified amount of memory.

The maximum amount of memory (RAM) an application needs to be configured in the Cloud Foundry Manifest or by using a CLI command. This is a critical step in ensuring your application runs smoothly.

An application with a memory limit of 128 MB can utilize all 8 CPUs, if no other application needs CPU power at that moment. This is because CPU power is distributed according to the memory requested for your application.

The following table shows how many CPU shares an application is allocated based on its configured memory limit.

Scaling for applications should be implemented horizontally instead of vertically to ensure that they are capable of handling the load.

Freeze Dependencies is a crucial step in ensuring your application's stability and security. You should create a package-lock.json file to freeze all dependencies, including transient ones.

This file helps you keep track of the exact versions of your dependencies, which is especially important if you're using multitenancy. If you are, you'll also need to freeze dependencies for the MTX sidecar.

Regularly updating your package-lock.json is essential to consume the latest versions and bug fixes. Running the command again to update the file is a good practice, especially after deploying a new version of your application.

In fact, it's recommended to run this command each time you deploy a new version to ensure you're using the latest and most secure dependencies. This will help you maintain a stable and secure application.

Cloud Foundry's build process is a crucial step in deploying your application. It involves combining your app's source code with the necessary dependencies and frameworks to create a deployable package.

Cloud Foundry includes the stack and buildpack with your app's source code, which are then combined into a droplet that can be unpacked, compiled, and run on a VM. This process is called staging.

You can specify the buildpack explicitly in the Cloud Foundry Manifest, or let Cloud Foundry automatically detect one for you. Currently, Cloud Foundry supports buildpacks for Java, Node.js, .NET Core, staticfile, Python, Ruby, PHP, and Go.

Here are the supported buildpacks:

To build your project, you can use the `cds build` command, which can take some minutes to complete. This process creates a log output that you can check for deployment logs.

CLI with MTA Plugins is a crucial step in setting up your Cloud Foundry environment. To check if you have the latest version of the Cloud Foundry CLI, run cf -v in a terminal.

If you're running a version lower than 8, you'll need to install or update it according to the Cloud Foundry CLI documentation.

To ensure you have the MTA plugin installed, follow these steps: Run cf add-plugin-repo CF-Community https://plugins.cloudfoundry.orgInstall the multiapps plugin with cf install-plugin multiappsInstall the html5-plugin with cf install-plugin html5-plugin