Guestbook was originally a Kubernetes example application, which has been modified for use as a Preview example.
Note that there are 2 difference examples on different branches of this repository
The guestbook application contains a single application, and a Redis dependency in a master/slave configuration.
In this example, we are not using a Helm chart to deploy the main application, but instead using flat Kubernetes manifest files. We are also using Kubernetes manifest files to deploy the Redis dependency.
You can again see in this example that we actually do not have any content in our config.yaml file. This is because we are deploying only manifests from the .preview/manifests/ directory.