Flux CD vs Kustomize

Flux CD vs Kustomize: What are the differences?

Developers describe Flux CD as "The GitOps operator for Kubernetes". It is a tool that automatically ensures that the state of your Kubernetes cluster matches the configuration you’ve supplied in Git. It uses an operator in the cluster to trigger deployments inside Kubernetes, which means that you don’t need a separate continuous delivery tool. On the other hand, Kustomize is detailed as "Kubernetes native configuration management". It introduces a template-free way to customize application configuration that simplifies the use of off-the-shelf applications. Now, built into kubectl as apply -k.

Flux CD and Kustomize can be primarily classified as "Container" tools.

Some of the features offered by Flux CD are:

• Describe the entire desired state of your system in Git. This includes apps, configuration, dashboards, monitoring, and everything else
• Use YAML to enforce conformance to the declared system. You don’t need to run kubectl because all changes go through Git. Use diffing tools to detect divergence between observed and desired state and receive notifications
• Everything is controlled through pull requests, which means no learning curve for new developers. Just use your standard PR process. Your Git history provides a sequence of transactions, allowing you to recover system state from any snapshot. Fix a production issue via pull request rather than making changes to the running system

On the other hand, Kustomize provides the following key features:

• Purely declarative approach to configuration customization
• Natively built into kubectl
• Manage an arbitrary number of distinctly customized Kubernetes configurations

Flux CD is an open source tool with 5.2K GitHub stars and 920 GitHub forks. Here's a link to Flux CD's open source repository on GitHub.