nomad-plugin-lvm

A Nomad dynamic host volume plugin for LVM thin provisioning.

Install

make build
cp build/nomad-plugin-lvm /opt/nomad/host_volume_plugins/

Reload the Nomad client (SIGHUP or systemctl reload nomad).

Persistent volumes

type      = "host"
name      = "myapp-data"
plugin_id = "nomad-plugin-lvm"

capacity_min = "1G"
capacity_max = "10G"

capability {
  access_mode     = "single-node-single-writer"
  attachment_mode = "file-system"
}

parameters {
  volume_group = "vg0"
  thin_pool    = "thinpool0"
}

nomad volume create myapp-data.volume.hcl

Creates a thin LV with an ext4 filesystem.

Snapshots

Create a thin snapshot of an existing LV:

type      = "host"
name      = "myapp-snap"
plugin_id = "nomad-plugin-lvm"

parameters {
  type         = "snapshot"
  source       = "myapp-base"
  volume_group = "vg0"
  thin_pool    = "thinpool0"
}

The source LV must already exist in the same volume group.

Parameters

All configuration is passed through the volume definition's parameters {} block:

Parameter	Required	Default	Description
volume_group	yes	—	LVM volume group name
thin_pool	yes	—	Thin pool name
type	no	persistent	persistent (new thin LV) or snapshot (COW clone)
source	snapshot	—	Source LV name (required when type = "snapshot")
filesystem	no	ext4	Filesystem for persistent volumes
mode	no	filesystem	filesystem or block
mount_dir	no	/srv/nomad-volumes	Volume mount directory
bin_path	no	/usr/sbin	Directory containing LVM, mount, and mkfs binaries

Requirements

• Nomad 1.10+ with dynamic host volumes
• LVM2 tools (lvcreate, lvremove, lvs, lvchange)
• An existing LVM thin pool