Achieving Data Locality - Running steps on same node

[itajaja]

Is there a way in Argo to specify that steps in the workflow need to run on the same node, so that they can share a hostpath volume? I am not sure how I could use affinity to achieve that with just kubernetes out of the box.

[terrytangyuan]

Yes, you can specify nodeSelector and affinity at either workflow or template level. Here's an example of using node selector in a step: https://github.com/argoproj/argo-workflows/blob/master/examples/node-selector.yaml

[itajaja]

thanks. but I am not sure you can use nodeSelector to point specifically to a node vs to a collection of nodes with same label

[alexec]

I think you can use pod-affinity to do this.

[itajaja]

Yes, you guys are totally right. I think colocation is somewhat orthogonal to Argo. thanks!