GitOps with Arlon
Starting release 5.6 of PMK, Platform9 is expanding our GitOps capabilities by adding support for open source Arlon to enable cluster fleet management at scale.
The Cluster Fleet Management w/ Arlon integration into PMK is still a beta feature in PMK release 5.6. We are actively working on making this feature GA in upcoming PMK releases.
What is Arlon
Arlon is a tool for scalable cluster and application lifecycle management for Kubernetes using the principles of GitOps and Infrastructure as Code (IaC). Arlon is built using open source ArgoCD and ClusterAPI. Arlon lets you define the desired state for your clusters and applications using a concept of a Profile. A Profile captures your cluster configuration information, along with information on what packages you wish to install on the cluster. Profiles are stored in your Git repository. You can use Arlon to create one or more clusters using a profile. Arlon then manages the relationship between the Profiles and the Clusters that are created using them. Any changes made to the profile are automatically propagated to the the clusters that the Profile is applied to. For eg, your Kubernetes version information is captured in your cluster profile. If you update the Kubernetes cluster version to the latest release that you would like to upgrade your clusters to, as soon as you commit that change to the profile into your Git repository, all clusters to which the profile is applied to will get upgraded to that version of Kubernetes. Similarly, if you add a new application definition for Wordpress server 1.1 to the application bundle portion of your profile, then Wordpress version 1.1 will get installed on all clusters that the profile maps to. For more information on Arlon, visit the Arlon website and read the Arlon documentation
PMK Integration with Arlon
PMK 5.6 is the first release of PMK that integrates with Arlon. PMK release 5.7 integrates with Arlon version 0.9.0.
Arlon in PMK enables you to create and manage EKS clusters using a GitOps based fleet management approach, as an alternative to creating clusters individually using the PMK UI / REST API. You can create an Arlon profile that defines your EKS cluster specification, along with specification of infrastructure plugins and applications that you would like to install on your EKS cluster, using the built in Arlon CLI - ArlonCTL. Arlon in PMK leverages the built in ArgoCD instance that comes as part of PMK that runs in the PMK management plane, and PMK's out of box support for Cluster API.
The difference between open source Arlon vs. Arlon shipped with PMK is primarily around how the management cluster is configured. Open source Arlon requires you to setup a management cluster, and run ArgoCD and ClusterAPI in it. In the case of Arlon integrated with PMK, this is completely taken care of for you via the PMK management plane.
To interact with Arlon that comes built in with PMK , you need to make use of ArlonCTL Reference