ibm / swift-backend-for-frontend

WARNING: This repository is no longer maintained ⚠️ This repository will not be updated.

WARNING: This repository is no longer maintained ⚠️

This repository will not be updated. The repository will be kept available in read-only mode.

Create and deploy a Swift Backend For Frontend (BFF) using Kitura

We have similar patterns available for Node.js, Java Spring, and Java Liberty as well!

In this code pattern, you will create a Backend for Frontend (BFF) web service using Kitura in Swift, matching a RESTful API documented in Swagger.

A BFF can be used to elegantly expose complex backend systems to multiple client-facing platforms, such as iOS and the web, without building a monolothic API that attempts to serve all clients equally. Different types of clients require different types of user experiences, and having a backend API tightly coupled to each specific user experience actually makes for a much more loosely coupled system overall. This pattern helps frontend teams iterate on features faster by giving them more control over the APIs they interact with, without affecting the user experience or development team driving a sister frontend.

When you have completed this code pattern, you will understand how to:

• Build out the Backend for Frontend (BFF) architecture pattern
• Deploy to Kubernetes, Cloud Foundry or a DevOps Pipeline
• Operate an application with monitoring and distributed trace
• Connect to provisioned services

Video

Learn more about the Backend for Frontend pattern in this tech talk:

Steps

As an alternative to the steps below, you can create this project as a starter kit on IBM Cloud, which automatically provisions required services, and injects service credentials into a custom fork of this pattern. Then, you can skip directly to step 3 below.

1. Install development tools
2. Configuration
3. Run

1. Install development tools

Local Development Tools Setup

• On Linux, install the Swift toolchain version v3.1.1.
• On macOS, install Xcode v8.3+

IBM Cloud development tools setup

1. Install IBM Cloud Developer Tools on your machine
2. Install the plugin with: ibmcloud plugin install dev -r "IBM Cloud"

2. Configuration

Your application configuration information is stored in config.json. If you selected services added to your project, you will see Cloudant, Object Storage, and other services with their connection information such as username, password, and hostname listed here. This is useful for connecting to remote services while running your application locally.

When you push your application to IBM Cloud, however, these values are no longer used, and instead IBM Cloud automatically connects to those bound services through the use of environment variables. The config.json file has been added to the .gitignore file so you don't accidently check in the secret credentials.

3. Run

Using IBM Cloud development CLI

The IBM Cloud development plugin makes it easy to compile and run your application if you do not have all of the tools installed on your computer yet. Your application will be compiled with Docker containers. To compile and run your app, run:

ibmcloud dev build
ibmcloud dev run

Using your local development environment

Once the Swift toolchain has been installed, you can compile a Swift project with:

swift build

Your sources will be compiled to your .build/debug directory.

Endpoints

Your application is running at: http://localhost:8080/ in your browser.

• Your Swagger UI is running on: /explorer
• Your Swagger definition is running on: /swagger/api

Troubleshooting

Using IBM Cloud development CLI, build and debug your app using:

ibmcloud dev build --debug
ibmcloud dev debug

License

This code pattern is licensed under the Apache License, Version 2. Separate third-party code objects invoked within this code pattern are licensed by their respective providers pursuant to their own separate licenses. Contributions are subject to the Developer Certificate of Origin, Version 1.1 and the Apache License, Version 2.

Apache License FAQ