Understanding Cloud Foundry Routing

Oct 13, 2025 by pynkocean.com 14 views

Introduction

Cloud Foundry is a popular platform-as-a-service (PaaS) that enables developers to deploy and manage applications in the cloud. One of the key features of Cloud Foundry is its ability to support multi-tenant applications, which can be accessed by multiple subscribers through a shared infrastructure. However, configuring multi-tenant applications in Cloud Foundry can be complex, especially when it comes to routing. In this article, we will explore the concept of multi-tenant application routing in Cloud Foundry and provide best practices for configuring wildcard domains.

Describe the Question

Hi colleagues,

I am following your guide here, which explains how to deploy a multi-tenant application in Cloud Foundry with an AppRouter.

According to the documentation, the AppRouter domain follows this structure:

https://route-prefix-YOUR_SUBDOMAIN.cfapps.YOUR_REGION.hana.ondemand.com/service

This suggests that a unique route is created for each subscription, using the format route-prefix-YOUR_SUBDOMAIN. However, Cloud Foundry does not support wildcard hostnames like route-prefix-*, meaning a separate route must be defined for each subscriber.

In contrast, a typical multi-tenant Cloud Foundry setup often uses the following structure:

YOUR_SUBDOMAIN.cfapps.YOUR_REGION.hana.ondemand.com/service

(where the subdomain itself acts as the hostname).

I expected that a single wildcard route (*) could be used to cover all subscriber subdomains instead of creating multiple routes, which could lead to scalability challenges.

Could you confirm if my understanding is correct? Additionally, what are the best practices for configuring Cloud Foundry applications to use a wildcard domain such as *.domain.sap.com?

Best Practices for Multi-Tenant Application Routing

Understanding Cloud Foundry Routing

Cloud Foundry uses a routing layer to direct incoming requests to the correct application instance. The routing layer is responsible for mapping the incoming request to the correct application instance based on the request URL.

Wildcard Domains in Cloud Foundry

Cloud Foundry does not support wildcard hostnames like route-prefix-*. This means that a separate route must be defined for each subscriber. However, Cloud Foundry does support wildcard domains like *.domain.sap.com. A wildcard domain is a domain that can be used to cover multiple subdomains.

Configuring Wildcard Domains in Cloud Foundry

To configure a wildcard domain in Cloud Foundry, you need to create a route that matches the wildcard domain. For example, to configure a wildcard domain *.domain.sap.com, you would create a route with the following format:

*.domain.sap.com

You can then associate this route with your application instance.

Benefits of Using Wildcard Domains

Using wildcard domains in Cloud Foundry offers several benefits, including:

Scalability: With wildcard domains, you can cover multiple subdomains with a single route, making it easier to scale your application.
Flexibility: Wildcard domains give you the flexibility to add or remove subdomains without having to create new routes.
Simplified Configuration: With wildcard domains, you can simplify your configuration by using a single route to cover multiple subdomains.

Common Use Cases for Wildcard Domains

Wildcard domains are commonly used in the following scenarios:

Multi-tenant applications: Wildcard domains are ideal for multi-tenant applications where multiple subscribers need to access the application through different subdomains.
Subdomain-based routing: Wildcard domains can be used to route incoming requests based on the subdomain.
Load balancing: Wildcard domains can be used to distribute incoming requests across multiple application instances.

Best Practices for Configuring Wildcard Domains

When configuring wildcard domains in Cloud Foundry, follow these best practices:

Use a consistent naming convention: Use a consistent naming convention for your wildcard domains to make it easier to manage and maintain.
Use a single route: Use a single route to cover multiple subdomains to simplify your configuration.
Associate the route with your application instance: Associate the route with your application instance to ensure that incoming requests are directed to the correct application instance.
Monitor your application performance: Monitor your application performance to ensure that the wildcard domain is not causing any performance issues.

Conclusion

In conclusion, wildcard domains are a powerful feature in Cloud Foundry that can help you simplify your configuration and improve the scalability of your application. By following the best practices outlined in this article, you can configure wildcard domains in Cloud Foundry and take advantage of their benefits.

Additional Resources

For more information on Cloud Foundry and wildcard domains, refer to the following resources:

FAQs

Q: What is a wildcard domain in Cloud Foundry?

A: A wildcard domain in Cloud Foundry is a domain that can be used to cover multiple subdomains.

Q: How do I configure a wildcard domain in Cloud Foundry?

A: To configure a wildcard domain in Cloud Foundry, you need to create a route that matches the wildcard domain and associate it with your application instance.

Q: What are the benefits of using wildcard domains in Cloud Foundry?

A: The benefits of using wildcard domains in Cloud Foundry include scalability, flexibility, and simplified configuration.

Q: What are some common use cases for wildcard domains in Cloud Foundry?

Introduction

In our previous article, we explored the concept of multi-tenant application routing in Cloud Foundry and provided best practices for configuring wildcard domains. In this article, we will continue the conversation with a Q&A session, addressing some of the most frequently asked questions about multi-tenant application routing in Cloud Foundry.

Q&A Session

Q: What is the difference between a wildcard domain and a subdomain?

A: A wildcard domain is a domain that can be used to cover multiple subdomains, whereas a subdomain is a domain that is a part of a larger domain. For example, *.domain.sap.com is a wildcard domain, while subdomain.domain.sap.com is a subdomain.

Q: How do I create a wildcard domain in Cloud Foundry?

A: To create a wildcard domain in Cloud Foundry, you need to create a route that matches the wildcard domain and associate it with your application instance. You can do this by using the Cloud Foundry CLI or the Cloud Foundry web interface.

Q: Can I use a wildcard domain with a specific subdomain?

A: Yes, you can use a wildcard domain with a specific subdomain. For example, you can create a wildcard domain *.domain.sap.com and associate it with a specific subdomain subdomain.domain.sap.com.

Q: How do I associate a wildcard domain with my application instance?

A: To associate a wildcard domain with your application instance, you need to create a route that matches the wildcard domain and associate it with your application instance. You can do this by using the Cloud Foundry CLI or the Cloud Foundry web interface.

Q: Can I use a wildcard domain with multiple application instances?

A: Yes, you can use a wildcard domain with multiple application instances. This is useful for load balancing and scaling your application.

Q: How do I monitor the performance of my application with a wildcard domain?

A: To monitor the performance of your application with a wildcard domain, you can use Cloud Foundry's built-in monitoring tools, such as the Cloud Foundry CLI or the Cloud Foundry web interface.

Q: Can I use a wildcard domain with a specific port?

A: Yes, you can use a wildcard domain with a specific port. For example, you can create a wildcard domain *.domain.sap.com:8080 and associate it with your application instance.

Q: How do I troubleshoot issues with my wildcard domain?

A: To troubleshoot issues with your wildcard domain, you can use Cloud Foundry's built-in troubleshooting tools, such as the Cloud Foundry CLI or the Cloud Foundry web interface.

Q: Can I use a wildcard domain with a specific SSL certificate?

A: Yes, you can use a wildcard domain with a specific SSL certificate. For example, you can create a wildcard domain *.domain.sap.com and associate it with a specific SSL certificate.

Q: How do I rotate my SSL certificate with a wildcard domain?

A: To rotate your SSL certificate with a wildcard domain, you need to update the SSL certificate associated with your wildcard domain. You can do this by using the Cloud Foundry CLI or the Cloud Foundry web interface.

Q: Can I use a wildcard domain with a specific DNS provider?

A: Yes, you can use a wildcard domain with a specific DNS provider. For example, you can create a wildcard domain *.domain.sap.com and associate it with a specific DNS provider.

Q: How do I configure my DNS provider with a wildcard domain?

A: To configure your DNS provider with a wildcard domain, you need to update the DNS records associated with your wildcard domain. You can do this by using the DNS provider's web interface or API.

Conclusion

In conclusion, wildcard domains are a powerful feature in Cloud Foundry that can help you simplify your configuration and improve the scalability of your application. By following the best practices outlined in this article and the Q&A session, you can configure wildcard domains in Cloud Foundry and take advantage of their benefits.

Additional Resources

For more information on Cloud Foundry and wildcard domains, refer to the following resources:

FAQs

Q: What is the difference between a wildcard domain and a subdomain?

A: A wildcard domain is a domain that can be used to cover multiple subdomains, whereas a subdomain is a domain that is a part of a larger domain.

Q: How do I create a wildcard domain in Cloud Foundry?

A: To create a wildcard domain in Cloud Foundry, you need to create a route that matches the wildcard domain and associate it with your application instance.

Q: Can I use a wildcard domain with a specific subdomain?

A: Yes, you can use a wildcard domain with a specific subdomain.

Q: How do I associate a wildcard domain with my application instance?

A: To associate a wildcard domain with your application instance, you need to create a route that matches the wildcard domain and associate it with your application instance.

Q: Can I use a wildcard domain with multiple application instances?

A: Yes, you can use a wildcard domain with multiple application instances.

Q: How do I monitor the performance of my application with a wildcard domain?

A: To monitor the performance of your application with a wildcard domain, you can use Cloud Foundry's built-in monitoring tools.

Q: Can I use a wildcard domain with a specific port?

A: Yes, you can use a wildcard domain with a specific port.

Q: How do I troubleshoot issues with my wildcard domain?

A: To troubleshoot issues with your wildcard domain, you can use Cloud Foundry's built-in troubleshooting tools.

Q: Can I use a wildcard domain with a specific SSL certificate?

A: Yes, you can use a wildcard domain with a specific SSL certificate.

Q: How do I rotate my SSL certificate with a wildcard domain?

A: To rotate your SSL certificate with a wildcard domain, you need to update the SSL certificate associated with your wildcard domain.

Q: Can I use a wildcard domain with a specific DNS provider?

A: Yes, you can use a wildcard domain with a specific DNS provider.

Q: How do I configure my DNS provider with a wildcard domain?

A: To configure your DNS provider with a wildcard domain, you need to update the DNS records associated with your wildcard domain.