Nomad

Nomad is a workload orchestrator to deploy and manage containers and non-containerized applications.

Installation

Known issues

NVIDIA not supported

NVIDIA support has been disabled due to there being no way to disable a non-existent driver being loaded. When compiled with NVIDIA support, the instance immediately crashes with the following error:

/usr/bin/nomad: undefined symbol: nvmlDeviceGetGraphicsRunningProcesses

The NVIDIA driver plugin will be externalised, see GitHub issue #8330.

Default plugin directory

The default plugin directory /var/lib/nomad/plugins has been changed to /usr/lib/nomad/plugins to reflect FHS.

Configuration

Nomad loads all configuration files in the /etc/nomad.d directory on startup.

See https://learn.hashicorp.com/tutorials/nomad/security-enable-tls to set up TLS encryption with Nomad.

Server

Create a configuration file at /etc/nomad.d/server.hcl:

Note: Replace the bootstrap_expect value with the number of Nomad servers you are deploying; three or five is recommended.

/etc/nomad.d/server.hcl

server {
  enabled = true
  bootstrap_expect = 3
}

Client

Create a configuration file at /etc/nomad.d/client.hcl:

/etc/nomad.d/client.hcl

client {
  enabled = true
}

Task drivers

Task drivers are used by Nomad clients to execute a task and provide resource isolation.

Nomad ships with support for the following task drivers out of the box:

Docker (requires docker)
Java (requires jre-openjdk or jre-openjdk-headless)
QEMU (requires qemu-desktop)
exec & raw_exec

containerd

In order to use the containerd driver, Install the nomad-driver-containerd package.

Enable the plugin in the client configuration, then Reload nomad.service.

/etc/nomad.d/containerd.hcl

plugin "containerd-driver" {
  config {
    # Arch Linux uses cgroups v2 by default
    # For cgroups v1, use "io.containerd.runc.v1"
    containerd_runtime = "io.containerd.runc.v2"
  }
}

Note: More configuration parameters can be found in upstream documentation.

podman

In order to user the podman driver, Install the nomad-driver-podman.

Nomad requires podman.service to be started.

Note: podman.service can also be started as a user systemd unit.

Enable the driver in the client configuration, then reload nomad.service.

/etc/nomad.d/podman.hcl

plugin "podman" {
  config {
    # Archlinux socket path for podman differs from the default value of socket_path (unix://run/podman/io.podman)
    socket_path = "unix://run/podman/podman.sock"
    # In case podman.service was started as user
    socket_path = "unix://run/user/USER_UID/podman/podman.sock"
  }
}