The app-of-apps pattern, while a useful concept, does have its pitfalls. The most significant is the complexity it introduces into application management. When you use the app-of-apps pattern, you're essentially managing applications within applications. This can become difficult to navigate, especially when applications begin to scale.
With a growing number of applications, it becomes challenging to keep track of all the interdependencies. Furthermore, when multiple teams are responsible for different applications, the complexity increases exponentially. This can lead to configuration drift and potential security risks, as the entire system's stability becomes dependent on each individual application.
In contrast, if we put the environment - the Kubernetes cluster - at the center of our thoughts, we can streamline our application management process. This doesn't mean we forget about applications, but rather, we view them as an integral part of the environment.
We can think of our environment as a living ecosystem, with applications as various organisms living within it. Rather than managing these organisms separately, we manage the ecosystem as a whole, ensuring that it remains healthy and balanced. This involves considering the system's stability, security, and ability to scale, as well as the interdependencies between various applications.
When we treat the environment as the central focus, we can apply a more holistic management approach. Using tools like Kustomize and ArgoCD, we can manage the Kubernetes cluster and its applications as a unified entity. This reduces complexity and makes it easier to maintain stability and security.
By using GitOps, we keep all our application's declarative configurations in a version-controlled system - Git. This enables automatic detection and remediation of configuration drift, thereby enhancing security and reliability.
Kustomize allows us to manage Kubernetes configurations through customization, and ArgoCD provides continuous delivery capabilities to deploy these configurations to the Kubernetes cluster. When used together, these tools can provide a powerful, declarative, and version-controlled approach to managing our Kubernetes environment.
While the app-of-apps pattern has its merits, it can introduce unnecessary complexity into Kubernetes application management. By shifting our focus to the environment - the Kubernetes cluster - and treating it as a unified entity with its applications, we can simplify management and enhance stability and security.
The combination of GitOps, Kustomize, and ArgoCD offers a powerful toolkit for managing our environment. They enable a declarative, version-controlled approach to configuration management that is both flexible and reliable. This makes it easier to maintain our environment and ensures our applications always run in a stable and secure ecosystem.