flannel #6

Supports: xenial


it is a generic overlay network that can be used as a simple alternative to existing software defined networking solutions

Flannel Charm

Flannel is a virtual network that gives a subnet to each host for use with container runtimes.

This charm will deploy flannel, render systemd templates, and allow the SDN to be related to any principal charm implementing the sdn-plugin interface.


The flannel charm is a subordinate. This charm will require a principal charm that implements the sdn-plugin interface in order to properly deploy.

juju deploy flannel
juju deploy etcd
juju deploy kubernetes-master
juju add-relation flannel kubernetes-master
juju add-relation flannel etcd


iface The interface to configure the flannel SDN binding. If this value is empty string or undefined the code will attempt to find the default network adapter similar to the following command:

route | grep default | head -n 1 | awk {'print $8'}

cidr The network range to configure the flannel SDN to declare when establishing networking setup with etcd. Ensure this network range is not active on the vlan you're deploying to, as it will cause collisions and odd behavior if care is not taken when selecting a good CIDR range to assign to flannel.

Known Limitations

This subordinate does not support being co-located with other deployments of the flannel subordinate (to gain 2 vlans on a single application). If you require this support please file a bug.

This subordinate also leverages juju-resources, so it is currently only available on juju 2.0+ controllers.

Further information


(string) Network CIDR to assign to Flannel
(string) The interface to bind flannel overlay networking. The default value is the result of running the following command: `route | grep default | head -n 1 | awk {'print $8'}`.