Node Affinity & Anti-Affinity with Gitlab Runner💣
Affinity is exposed through values options for this package. If you want to schedule your pods to deploy on specific nodes you can do that through the nodeSelector value and as needed the affinity value. Additional info is provided below as well to help in configuring this.
It is good to have a basic knowledge of node affinity and available options to you before customizing in this way - the upstream kubernetes documentation has a good walkthrough of this.
Values for NodeSelector💣
The nodeSelector value at the top level can be set to do basic node selection for deployments. See the below example for an example to schedule pods to only nodes with the label node-type equal to runner:
nodeSelector:
node-type: runner
Values for Affinity💣
The affinity value at the top level should be used to specify affinity. The format to include follows what you’d specify at a pod/deployment level. See the example below for scheduling the operator pods only to nodes with the label node-type equal to runner:
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
nodeSelectorTerms:
- matchExpressions:
- key: node-type
operator: In
values:
- runner
Values for Anti-Affinity💣
The affinity value at the top level can be set in the same way to schedule pods based on anti-affinity. See the below example to schedule pods to not be present on the nodes that already have pods with the dont-schedule-with: runner label:
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- topologyKey: "kubernetes.io/hostname"
labelSelector:
matchLabels:
dont-schedule-with: runner