Rancher Drivers for Clusters and Nodes

In the previous sections, we created a Rancher-launched Kubernetes cluster using DigitalOcean as the cloud provider. We used the built-in DigitalOcean driver to create the cluster. In this section, we will explore the concept of drivers in Rancher and how they are used to create clusters and nodes.

One of the most helpful features of Rancher is its ability to create Kubernetes clusters on various cloud providers or on-premises infrastructure. The process of creating a cluster in Rancher is straightforward and can be done in a few clicks using the UI. You can also create clusters using the Rancher CLI or the Rancher API.

When creating a cluster in Rancher, you can choose from a list of Kubernetes distributions, including RKE and RKE2/K3s. You can also select the cloud provider where you want to create the cluster, such as DigitalOcean, AWS, Azure, or GCP. Rancher provides a wide range of options for customizing the cluster, such as the number of nodes, the instance type, the Kubernetes version, the Kubernetes distribution (RKE, RKE2, or K3s), the network plugin (e.g., Canal, Calico, Flannel), and more.

Cluster Drivers

Since Rancher can create clusters on various cloud providers, it needs a way to interact with them to provision the necessary resources. This is where cluster drivers come into play. A cluster driver is a plugin that allows Rancher to communicate with a specific cloud provider's API to create and manage Kubernetes clusters. Each cloud provider has its own driver that is responsible for handling the interactions between Rancher and the cloud provider's API.

For example, to create a GKE cluster from Rancher, you will typically need two things:

• A Google Cloud Platform service account with the necessary permissions to create a GKE cluster.
• The Google Cloud Platform driver installed in Rancher.

The same applies to other cloud providers like AWS, Azure, DigitalOcean, and others with slight variations. The cluster driver is what Rancher uses to interact with the cloud provider's API to create the cluster. While it is possible to import and install new drivers in Rancher, the platform comes with a set of built-in drivers for popular cloud providers including:

• Alibaba ACK
• Amazon EKS
• Azure AKS
• Baidu CCE
• Google GKE
• Huawei CCE
• Linode LKE
• Open Telekom Cloud CCE
• Oracle OKE
• Tencent TKE

Some of these drivers are enabled by default in Rancher, while others need to be enabled. You can enable or disable drivers by going to Cluster Management > Drivers > Cluster Drivers. You can also create custom drivers if you want to use a cloud provider that is not supported out of the box.

ℹ️ If your cloud provider is not supported by Rancher and if it has no driver, you can create a custom driver, which is a bit more advanced. Alternatively, you can create the cluster using your cloud provider's console, CLI, or even Terraform, and then import it into Rancher. In this case, you will not be able to fully manage the cluster from Rancher, but you will still be able to see the cluster, its resources, install apps, monitor it, and more.

Node Drivers

Let's say you don't want to use AWS EKS to create a cluster in Rancher, but you want to use EC2 instances. Rancher can help you with this. However, it needs a "connector" to interact with the AWS API to create the instances, install the different components, and form a Kubernetes cluster. This is where the EC2 node driver comes in.

The good news is that it's already enabled in Rancher by default. You can see it by going to Cluster Management > Drivers > Node Drivers. You will not only find the EC2 node driver but also other node drivers for different cloud providers. Here is the list of the default ones:

• Aliyun ECS
• Amazon EC2
• Azure
• Cloud.ca
• Cloudscale
• DigitalOcean
• Equinix Metal
• Exoscale
• Google GCE