Using Rancher, you can create pools of nodes based on a node template. The benefit of using a node pool is that if a node loses connectivity with the cluster, Rancher will automatically create another node to join the cluster to ensure that the count of the node pool is as expected.
Each node pool is assigned with a node component to specify how these nodes should be configured for the Kubernetes cluster.
A node template is the saved configuration for the parameters to use when provisioning nodes in a specific cloud provider. Rancher provides a nice UI to be able to launch these nodes and uses Docker Machine to provision these nodes. The available cloud providers to create node templates are based on the active node drivers in Rancher.
After you create a node template in Rancher, it’s saved so that you can use this template again to create other node pools. Node templates are bound to your login. After you add a template, you can remove them from your user profile.
Available as of v2.2.0
Node templates can use cloud credentials to store credentials for launching nodes in your cloud provider, which has some benefits:
Cloud credentials are stored as Kubernetes secrets for security. Credentials are no longer needed to be re-entered any time you want to edit a node template.
After the cloud credential is created, it can be re-used to create additional node templates.
When access and secret keys are expired or compromised, the cloud credential can be updated with the new information, which will automatically be updated for all the node templates referencing this cloud credential.
Note: As of v2.2.0, the default
activenode drivers and any node driver, that has fields marked as
password, are required to use cloud credentials. If you have upgraded to v2.2.0, existing node templates will continue to work with the previous account access information, but when you edit the node template, you will be required to create a cloud credential and the node template will start using it.
After cloud credentials are created, the user can start managing the cloud credentials that they created.