Cloud Foundry: The Definitive Guide

Chapter 7. Routing Considerations

This chapter looks at Cloud Foundry’s routing mechanisms in more detail. User-facing apps need to be accessed by a URL, often referred to in Cloud Foundry parlance as a route. End users target the URL for the app that they want to access. The app then hopefully returns the correct response. However, there is often a lot more going on behind that simple request–response behavior.

Operators can use routing mechanisms for reasons such as to provide additional security, ease deployment across a microservices architecture, and avoid downtime during upgrades through well-established techniques such as deploying canaries and establishing blue/green deployments. For these reasons, an understanding of Cloud Foundry’s routing mechanisms along with an appreciation of the routing capabilities is an important operational concern. Additionally, understanding how different Cloud Foundry components dynamically handle routing is important for debugging platform- or app-routing issues.

Routing Primitives

The Cloud Foundry operator deals with the following:

• Routes

• Hostnames

• Domains

• Context paths

• Ports

The Cloud Foundry documentation explores these concepts at length. This chapter explores the key considerations for establishing routing best practices. We begin with a brief introduction to the terms and then move on to the routing mechanisms and capabilities.

Routes

To enable traffic from external clients, apps require a specific URL, known as a route. ...