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. As of Rancher v2.4, Rancher can be installed on a K3s cluster.
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.
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.
For Rancher v2.0-v2.4, there is no migration path from a Docker installation to a high-availability installation. Therefore, you may want to use a Kubernetes installation from the start.
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||These docs, plus this configuration||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.
The type of cluster that Rancher needs to be installed on depends on the Rancher version.
For Rancher v2.4.x, either an RKE Kubernetes cluster or K3s Kubernetes cluster can be used. For Rancher before v2.4, an RKE cluster must be used.
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: