# Requirements

If you are planning to run Deis Workflow on your own Kubernetes cluster there are a few requirements that you should be
aware of when creating your environment.

## Resource Requirements

When deploying Deis Workflow, it's important to provision machines with adequate resources. Deis is a highly-available
distributed system, which means that Deis components and your deployed applications will move around the cluster onto
healthy hosts as hosts leave the cluster for various reasons (failures, reboots, autoscalers, etc.). Because of this,
you should have ample spare resources on any machine in your cluster to withstand the additional load of running
services for failed machines.

Deis Workflow components consume approximately 2 - 2.5GB of memory across the cluster, and approximately 30GB of hard
disk space. Because each machine should be able to absorb additional load should a machine fail, each machine must
have:

* At least 4GB of RAM (more is better)
* At least 40GB of hard disk space

Note that these estimates are for Deis Workflow and Kubernetes only. Be sure to leave enough spare capacity for your
application footprint as well.

Running smaller machines will likely result in increased system load and has been known to result in component failures and instability.

## Kubernetes Versions

Deis Workflow has been tested with the **Kubernetes v1.2** release line. It is incompatible with Kubernetes v1.1 and earlier.

## Docker Insecure Registry

The on-cluster Docker registry is not deployed with TLS enabled. As such, all Kubernetes worker nodes must have their
Docker daemons configured to use an **insecure registry**. The configured subnet should encompass any private networks
used by your worker nodes, including overlay networks.

Depending on your Kubernetes and Docker configuration, setting `EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8"` may
be sufficient.

## SELinux + OverlayFS

If you are using Docker with OverlayFS you must disable SELinux by adding `--selinux-enabled=false` to
`EXTRA_DOCKER_OPTS`. For more background information see:

* [https://github.com/docker/docker/issues/7952](https://github.com/docker/docker/issues/7952)
* [https://github.com/deis/postgres/issues/63](https://github.com/deis/postgres/issues/63)