This section provides an overview of the architecture options of installing Rancher, describing advantages of each option.
In this section,
- The Rancher server manages and provisions Kubernetes clusters. You can interact with downstream Kubernetes clusters through the Rancher server's user interface.
- RKE (Rancher Kubernetes Engine) is a certified Kubernetes distribution and CLI/library which creates and manages a Kubernetes cluster.
- K3s (Lightweight Kubernetes) is also a fully compliant Kubernetes distribution. It is newer than RKE, easier to use, and more lightweight, with a binary size of less than 100 MB.
- RKE2 is a fully conformant Kubernetes distribution that focuses on security and compliance within the U.S. Federal Government sector.
- RancherD was an experimental tool for installing Rancher; a single binary that first launched an RKE2 Kubernetes cluster, then installed the Rancher server Helm chart on the cluster. It was available as part of Rancher v2.5.4 through v2.5.10 but is now deprecated and not available for recent releases.
Changes to Installation in Rancher v2.5
In Rancher v2.5, the Rancher management server can be installed on any Kubernetes cluster, including hosted clusters, such as Amazon EKS clusters.
For Docker installations, a local Kubernetes cluster is installed in the single Docker container, and Rancher is installed on the local cluster.
restrictedAdmin Helm chart option was added. When this option is set to true, the initial Rancher user has restricted access to the local Kubernetes cluster to prevent privilege escalation. For more information, see the section about the restricted-admin role.
Overview of Installation Options
Rancher can be installed on these main architectures:
High-availability Kubernetes Install with the Helm CLI
We recommend using Helm, a Kubernetes package manager, to install Rancher on multiple nodes on a dedicated Kubernetes cluster. For RKE clusters, three nodes are required to achieve a high-availability cluster. For K3s clusters, only two nodes are required.
High-availability Kubernetes Install with RancherD
Note: RancherD was an experimental feature available as part of Rancher v2.5.4 through v2.5.10 but is now deprecated and not available for recent releases.
RancherD is a single binary that first launches an RKE2 Kubernetes cluster, then installs the Rancher server Helm chart on the cluster.
In both the RancherD install and the Helm CLI install, Rancher is installed as a Helm chart on a Kubernetes cluster.
Configuration and upgrading are also simplified with RancherD. When you upgrade the RancherD binary, both the Kubernetes cluster and the Rancher Helm chart are upgraded.
Single-node Kubernetes Install
Rancher can be installed on a single-node Kubernetes cluster. In this case, the Rancher server doesn't have high availability, which is important for running Rancher in production.
However, this option is useful if you want to save resources by using a single node in the short term, while preserving a high-availability migration path. In the future, you can add nodes to the cluster to get a high-availability Rancher server.
For test and demonstration purposes, Rancher can be installed with Docker on a single node.
The Rancher backup operator can be used to migrate Rancher from the single Docker container install to an installation on a high-availability Kubernetes cluster. For details, refer to the documentation on migrating Rancher to a new cluster.
There are also separate instructions for installing Rancher in an air gap environment or behind an HTTP proxy:
|Level of Internet Access||Kubernetes Installation - Strongly Recommended||Docker Installation|
|With direct access to the Internet||Docs||Docs|
|Behind an HTTP proxy||Docs||These docs, plus this configuration|
|In an air gap environment||Docs||Docs|
We recommend installing Rancher on a Kubernetes cluster, because in a multi-node cluster, the Rancher management server becomes highly available. This high-availability configuration helps maintain consistent access to the downstream Kubernetes clusters that Rancher will manage.
For that reason, we recommend that for a production-grade architecture, you should set up a high-availability Kubernetes cluster, then install Rancher on it. After Rancher is installed, you can use Rancher to deploy and manage Kubernetes clusters.
For testing or demonstration purposes, you can install Rancher in single Docker container. In this Docker install, you can use Rancher to set up Kubernetes clusters out-of-the-box. The Docker install allows you to explore the Rancher server functionality, but it is intended to be used for development and testing purposes only.
Our instructions for installing Rancher on Kubernetes describe how to first use K3s or RKE to create and manage a Kubernetes cluster, then install Rancher onto that cluster.
When the nodes in your Kubernetes cluster are running and fulfill the node requirements, you will use Helm to deploy Rancher onto Kubernetes. Helm uses Rancher's Helm chart to install a replica of Rancher on each node in the Kubernetes cluster. We recommend using a load balancer to direct traffic to each replica of Rancher in the cluster.
For a longer discussion of Rancher architecture, refer to the architecture overview, recommendations for production-grade architecture, or our best practices guide.
Before installing Rancher, make sure that your nodes fulfill all of the installation requirements.
For the best performance and greater security, we recommend a separate, dedicated Kubernetes cluster for the Rancher management server. Running user workloads on this cluster is not advised. After deploying Rancher, you can create or import clusters for running your workloads.
For more architecture recommendations, refer to this page.
More Options for Installations on a Kubernetes Cluster
Refer to the Helm chart options for details on installing Rancher on a Kubernetes cluster with other configurations, including:
- With API auditing to record all transactions
- With TLS termination on a load balancer
- With a custom Ingress
In the Rancher installation instructions, we recommend using K3s or RKE to set up a Kubernetes cluster before installing Rancher on the cluster. Both K3s and RKE have many configuration options for customizing the Kubernetes cluster to suit your specific environment. For the full list of their capabilities, refer to their documentation:
More Options for Installations with Docker
Refer to the docs about options for Docker installs for details about other configurations including: