Support volume mounts (e.g. nfs) for Kubernetes

[sjawhar]

Requested Functionality

If you're using k8s as your compute environment and you're operating on-prem, it's quite likely that you also have some kind of shared storage system (e.g. NFS). The user should be able to specify such volume mounts for their TPI task.

Candidate Implementation

See https://github.com/iterative/terraform-provider-iterative/compare/master...sjawhar:terraform-provider-iterative:feature/nfs-volume#diff-0fe990bc324a7948aa5a28972474908770afb9f012a7d0586ee0b4af8f808d8eR200-R216

Relevant section in TF would look like this:

resource "iterative_task" "task_with_nfs_volume" {
  cloud = "k8s"
  nfs_volume {
    server      = "10.0.20.3"
    server_path = "/data/projects"
    mount_path  = "/projects"
  }
}

[0x2b3bfa0]

Isn't a StorageClass the traditional approach to solve this use case? 🤔

[sjawhar]

Isn't a StorageClass the traditional approach to solve this use case? thinking

I don't think so? I based my implementation on the Kubernetes plugin for Jenkins, which generates pod specs that look like this:

apiVersion: "v1"
kind: "Pod"
spec:
  containers:
  - command:
    - "/bin/bash"
    image: "python3.9"
    volumeMounts:
    - mountPath: "/mount/path/here"
      name: "volume-0"
      readOnly: false
    workingDir: "/home/jenkins/agent"
  nodeSelector:
    nodetype: "cpu"
  restartPolicy: "Never"
  volumes:
  - name: "volume-0"
    nfs:
      path: "/server/path/here"
      readOnly: true
      server: "10.0.20.3"