Integration with Flannel

What is Flannel?

Flannel is a very simple overlay network that provides an easy way to configure a layer 3 network fabric designed for Kubernetes. Flannel runs a small, single binary agent called flanneld on each host, and is responsible for allocating a subnet lease to each host out of a larger, preconfigured address space. Flannel uses either the Kubernetes API or etcd directly to store the network configuration, the allocated subnets, and any auxiliary data (such as the host’s public IP). Packets are forwarded using one of several backend mechanisms including VXLAN and various cloud integrations.

For more information on Flannel, refer to Project Flannel Github Page.

Flannel may be paired with several different backends. Platform9 Managed Kubernetes supports deploying Flannel with two backend options - using Flannel with UDP backend, or using Flannel with VXLAN backend and with Calico for network policies.

This article describes using Flannel with UDP backend as the networking layer for your Managed Kubernetes clusters. Refer to Calico with Flannel Networking for more information on using Flannel with VXLAN backend along with Calico for network policies.

Cloud Provider Support Matrix and Prerequisites

Cloud providerSupport for FlannelPrerequisites
Bare Metal ProviderYes
  • Follow the general purpose Networking Prerequisites
  • Port 8285 must be open on all nodes of the cluster for UDP protocol
AWS ProviderYesNone. All prerequisites are configured by the Managed Kubernetes AWS Provider
Azure ProviderYesNone. All prerequisites are configured by the Managed Kubernetes Azure Provider
OpenStack ProviderYes
  • Follow the general purpose Networking Prerequisites
  • Port 8285 must be open on all nodes of the cluster for UDP protocol
VMware ProviderYes
  • Follow the general purpose Networking Prerequisites
  • Port 8285 must be open on all nodes of the cluster for UDP protocol

Create Cluster Using Flannel With UDP Backend

While creating the cluster, under Network Configuration, select Flannel as the network option.