user_guide.md

User guide

Applying configurations

All configurations are declared in NodeConfig manifests, which are applied in the same way as all kubernetes objects.

1. Write your manifest, for instance:

apiVersion: configuration.whitestack.com/v1beta2
kind: NodeConfig
metadata:
  name: nodeconfig-sample
spec:
  kernelParameters:
    parameters:
    - name: fs.file-max
      value: "54321"
    state: present

1. Save it with a convenient name, e.g. sample_node_config.yaml

2. In order to apply the manifest, execute the following command:

   kubectl apply -f sample_node_config.yaml

Grouping configurations with node selectors

NodeConfig objects can be limited to specific nodes by using kubernetes labels.

Consider a cluster with nodes node-0, node-1 and node-2, and the previous NodeConfig manifest.

In order to apply the configuration to node-0 and node-1 only, execute the following procedure:

1. Add a label to nodes node-0 and node-1: kubectl label node-0 node-1 mylabel=test

2. Edit the NodeConfig object and add a nodeSelector with the same label:

apiVersion: configuration.whitestack.com/v1beta2
kind: NodeConfig
metadata:
  name: nodeconfig-sample
spec:
  nodeSelector:
  - key: "mylabel"
    operator: In
    values:
    - "test"
  kernelParameters:
    parameters:
    - name: fs.file-max
      value: "54321"
    state: present

1. Apply the changes.

Removing configurations

To remove a module's configuration you have to set the state field to absent and apply the CR to the cluster. You can check in the logs if it's been successfully removed.