Flux CD

Flux CD applies GitOps to Kubernetes. You declare the state you want in version-controlled configuration. Controllers inside the cluster fetch that configuration and reconcile the cluster toward it.

This model changes the delivery path. A continuous integration system can build and test an image, then update a repository. Flux pulls the declared state from that source. It does not need a deployment job with broad, permanent access to every cluster.

The central mental model

Think in terms of a control loop:

1. You record desired state in a source.
2. A Flux source controller fetches that state as an artifact.
3. A reconciler builds or interprets the artifact.
4. The reconciler compares desired and observed state.
5. It applies changes and reports status.
6. The loop runs again at the configured interval or after an event.

Reconciliation is the key idea. Flux does not run a one-time deployment and walk away. It continues checking. A corrected Git commit changes the desired state. A manual cluster edit creates drift that a later reconciliation can reverse when pruning and ownership settings cover that resource.

The controllers