Multi-cluster GitOps with the Argo CD Agent Technology Preview

Running a single instance of Argo CD on a single cluster used to be common, but now a multi-cluster GitOps architecture has become the norm. This way of working does come with its own set of challenges. Typically organizations have had to make compromises when deploying Argo CD in varying topologies depending on their specific priorities (for example, management or scalability). But multi-cluster deployments just got easier to manage and secure with the Argo CD Agent in Red Hat OpenShift GitOps. A new addition to the GitOps operator, the agent is part of the Red Hat OpenShift Platform Plus (OPP) subscription.

Topologies for Argo CD

Broadly, there are two common topologies for implementing Argo CD. The first is centralized, in which a single Argo CD instance runs in a management cluster and is responsible for deploying resources across a fleet of OpenShift or Kubernetes clusters. This provides for a single pane of glass which simplifies management, but can become challenging to scale as the number of applications and clusters grow.

The other common topology is distributed, in which Argo CD is distributed across the fleet of OpenShift or Kubernetes clusters. This provides increased scalability, but also increases the complexity of provisioning and managing those instances.

Scale has become the major blocker for large production implementations. It's not just Argo CD's performance that's important. You also must consider scaling observability, instance management, and security. The footprint of Argo CD can be large, especially if you're deploying large applications, and resource consumption matters increasingly more as your deployments get closer to the edge.

Instead of addressing each of these challenges individually, we looked holistically at how customers are interacting with Argo and what they're trying to accomplish. Agentic pull models have become popular across our industry in recent years, for good reason. Introducing an agent to Argo CD allows us to tackle all of these multi-cluster challenges at once.

What is the Argo CD Agent?

The OpenShift GitOps team is introducing an agent model to Argo CD. The Argo CD Agent is a small Go binary that runs on your remote clusters, and communicates back to the Argo CD instance on your central management cluster.

Centralized visibility and insights

While a centralized model offers a single pane of glass, it suffers from significant scaling, performance, and security challenges as the number of clusters and applications grows. The Argo CD Agent topology enables central visibility in the control plane, while offloading the workloads themselves to your remote clusters managed by the local agents.

Reduce Argo CD resource usage

You don't have to endure scalability issues with resource constrained clusters, or uneven distribution of compute resources. Using Argo CD Agent, you can split up the pieces of Argo CD across clusters, reducing the required resources on each cluster. This also means you can share common components centrally, while distributing those that are specific to clusters, teams, or applications. If you've got an application with much higher compute requirements than others, that could now run on a separate cluster with greater GPU support or more RAM.

Best of both topologies

In summary, the Agent model combines the best of the centralized and distributed topologies. It provides for a single pane of glass for managing applications while improving scalability by distributing key components of Argo CD across the fleet of OpenShift and Kubernetes clusters.

Integration with Red Hat Advanced Cluster Management

OpenShift GitOps has been collaborating with the Red Hat Advanced Cluster Management team on a tight integration between the two products. A forthcoming add-on for the Argo CD Agent will be our recommended way to manage the Agent on remote clusters, leveraging existing and extensive multi-cluster management features of Red Hat Advanced Cluster Management.

Advanced Cluster Management is expecting to release a technology preview of the Argo CD Agent as an add-on with the 2.15 release, targeted for Q4 of 2025

The road ahead

Red Hat is planning for this feature to become generally available (GA) in OpenShift GitOps 1.19 later in 2025. OpenShift GitOps 1.18 already includes improvements based on early feedback and suggestions from customers.

The GA release focuses on stability and compliance, as well as a few key feature additions. We're adding support for running in FIPS environments, as well as private repo support to match our existing OpenShift GitOps offering. There's also support for streaming pod logs from agents back to the principal. Official documentation will also be incrementally added as we approach GA.

Getting started

The Argo CD Agent is available now as technical preview from OpenShift GitOps 1.17 and above, and this provides an opportunity for you to try out the technology in non-production environments and provide feedback as we move towards general availability. To get started, read the documentation for installing and using the Agent.

Prerequisites:

• OpenShift GitOps v1.17.0
• Requires an OPP subscription on each cluster that runs the OpenShift GitOps Agent. The control plane of OpenShift GitOps is still available with OCP, but usage of the Agent requires an OPP subscription at point of use.

The Agent is installed as two components:

• Principal: Installed on the Control Plane cluster and managed by the operator.
• Agent: Installed by a Helm chart on the managed clusters.

Please share any feedback with your account team — we look forward to hearing your thoughts and ideas.

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