When deploying Deis, 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 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 and Kubernetes only, and there should be ample room for deployed applications.
Running smaller machines will likely result in increased system load and has been known to result in component failures and other problems.
Deis workflow has been tested with the Kubernetes v1.2 release line. It is incompatible with Kubernetes v1.1 and lower.
The on-cluster, Deis-managed Docker registry is not deployed with TLS by default. As such, all Kubernetes worker nodes must have their Docker daemons configured to use an insecure registry. The subnet should encompass any private networks used by your worker nodes, including any overlay networks. Depending on your Kubernetes and Docker configuration, setting EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8" may be sufficient.
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: