»csi_plugin Stanza

Placementjob -> group -> task -> volume

The "csi_plugin" stanza allows the task to specify it provides a Container Storage Interface plugin to the cluster. Nomad will automatically register the plugin so that it can be used by other jobs to claim volumes.

csi_plugin {
  id        = "csi-hostpath"
  type      = "monolith"
  mount_dir = "/csi"
}

»csi_plugin Parameters

  • id (string: <required>) - This is the ID for the plugin. Some plugins will require both controller and node plugin types (see below); you need to use the same ID for both so that Nomad knows they belong to the same plugin.

  • type (string: <required>) - One of node, controller, or monolith. Each plugin supports one or more types. Each Nomad client node where you want to mount a volume will need a node plugin instance. Some plugins will also require one or more controller plugin instances to communicate with the storage provider's APIs. Some plugins can serve as both controller and node at the same time, and these are called monolith plugins. Refer to your CSI plugin's documentation.

  • mount_dir (string: <required>) - The directory path inside the container where the plugin will expect a Unix domain socket for bidirectional communication with Nomad.

»csi_plugin Examples

job "plugin-efs" {
  datacenters = ["dc1"]

  # you can run node plugins as service jobs as well, but running
  # as a system job ensures all nodes in the DC have a copy.
  type = "system"

  # only one plugin of a given type and ID should be deployed on
  # any given client node
  constraint {
    operator = "distinct_hosts"
    value = true
  }

  group "nodes" {
    task "plugin" {
      driver = "docker"

      config {
        image = "amazon/aws-efs-csi-driver:latest"

        args = [
          "node",
          "--endpoint=unix://csi/csi.sock",
          "--logtostderr",
          "--v=5",
        ]

        # all CSI node plugins will need to run as privileged tasks
        # so they can mount volumes to the host. controller plugins
        # do not need to be privileged.
        privileged = true
      }

      csi_plugin {
        id        = "aws-efs0"
        type      = "node"
        mount_dir = "/csi"  # this path /csi matches the --endpoint
                            # argument for the container
      }
    }
  }
}