What is Flux, and Why is it Unique?
One of the instruments out there for the distribution side of the CI/CD ratio for Kubernetes implementation goals is Flux, a project of CNCF sandbox.
Flux stands out for many reasons when you look at the millions of other CI/CD systems, applications, and cloud-based services nowadays. First, it just deals with the continuous distribution side of the CI/CD (Flux is not for constructing artifacts); second, its expressly tailored execution frameworks for Kubernetes, and third, its centric GitOps.
CD using Flux
Anytime you build custom applications since CI/CD pipelines are applications, you typically must store the system’s “condition” or “desired state” somewhere; this may be an RDBMS, NoSQL API system, etc. With GitOps, you define the system’s expected state tastefully using Git because you are free to use all the constructions and functionality that Git provides for history. For your method, Git becomes the primary source of truth for the past and lineage of all acts performed over time. You can (in theory) still “reset” your state back to some previous point in the process by using Git as your root of reality by which all acts stem, relying, of course, on the skill of the user of the mentioned state.
The Role of GitOps
Hence, GitOps is essentially a way to do DevOps. Modifications to the Git repository cause all downstream behavior in the environment, precisely the framework Flux operates in. It is worth remembering that the Git archive that manages a framework of CDs may not even be the same archive that the structures of CI can consume to create the objects that the programs of CDs ultimately transmits to target running environments.
When using Flux, you install a Flux daemon on your CD device (i.e., when program objects are deployed to), on a specified Kubernetes cluster. The relationship between and Flux daemon and a Git registry is of one to one nature, where the daemon uses a setup that informs Flux which “condition” to add to the k8s within a Flux daemon. (i.e., the Git repo provides regular YAML manifestations to k8s, as well as map statements from HelmRelease). Flux effectively responds to the modifications made to this Git repository. It updates the Kubernetes by adding the modified YAML k8s (or HelmReleases through calling Helm itself through the use of the Flux helm operator inside the cluster). Also, Flux can build raw k8s manifestations of YAML through tools such as Customization.
Flux also has the advantage that, with its “automating” function for each Docker container: tag linked in the YAML or Helm Releases Git registry, it may potentially track Docker registries or repositories, that is totally at your disposal. This is because Flux will sense this and instantly update formerly used YAML k8s with the new picture tag found, implement the cluster shift (and update the Flux-related Git configuration file with the original image referee). You can impose updates manually to the Flux daemon using the call-up function, which will be mirrored back into the Git repository when the updates demanded are implemented to ensure that the status declared is current. e.g., you can directly upgrade a current flux called a “workload” to use the earlier image via fluxctl, upgrade the pods into a new image of your cluster, and in turn, configure the YAML/Helm transfer to the Flux configuration file. The Fluxctl CLI provides many different features, including lock/unlock, rollbacks and toggling workload automation, etc.
Flux with Helm
Flux can cope only with YAML manifestations’ simple default Kubernetes’ types (static or created or even deployments). You mount the helm-operator on your k8s cluster (the same place where your Flux daemon is configured). This controller or operator provides access for the latest helm CRD API, which supports the category “Helm Release” k8s API. You will specify which map you want to configure/overhaul, the values, etc., with Helm Release directories and related Helm release management software such as Helmfile.
It can prove more challenging to move to Flux if you have current implementation frameworks that use other software with various degrees of customization, but this can differ massively on a case to case basis. Flux is a CD structure you will need to fit into, it’s relatively accessible, but it has certain drawbacks you also have to be mindful about