---
layout: "docs"
page_title: "Drivers: Rkt"
sidebar_current: "docs-drivers-rkt"
description: |-
  The rkt task driver is used to run application containers using rkt.
---

# Rkt Driver - Experimental

Name: `rkt`

The `rkt` driver provides an interface for using CoreOS rkt for running
application containers. Currently, the driver supports launching
containers but does not support resource isolation or dynamic ports. This can
lead to resource over commitment and port conflicts and as such, this driver is
being marked as experimental and should be used with care.

## Task Configuration

The `rkt` driver supports the following configuration in the job spec:

* `trust_prefix` - **(Optional)** The trust prefix to be passed to rkt. Must be reachable from
the box running the nomad agent. If not specified, the image is run without
verifying the image signature.
* `image` - **(Required)** The image to run which may be specified by name,
hash, ACI address or docker registry.
* `command` - **(Optional**) A command to execute on the ACI.
* `args` - **(Optional**) A string of args to pass into the image.

## Task Directories

The `rkt` driver does not currently support mounting the `alloc/` and `local/`
directory. It is currently blocked by this [rkt
issue](https://github.com/coreos/rkt/issues/761). As such the coresponding
[environment variables](/docs/jobspec/environment.html#task_dir) are not set.

## Client Requirements

The `rkt` driver requires rkt to be installed and in your systems `$PATH`.
The `trust_prefix` must be accessible by the node running Nomad. This can be an
internal source, private to your cluster, but it must be reachable by the client
over HTTP.

## Client Attributes

The `rkt` driver will set the following client attributes:

* `driver.rkt` - Set to `1` if rkt is found on the host node. Nomad determines
this by executing `rkt version` on the host and parsing the output
* `driver.rkt.version` - Version of `rkt` eg: `0.8.1`
* `driver.rkt.appc.version` - Version of `appc` that `rkt` is using eg: `0.8.1`

## Resource Isolation

This driver does not support any resource isolation as of now.