Overview
This interface layer handles the communication with SDN providers like flannel via the sdn-plugin
interface.
Usage
Requires
This interface layer will set the following states, as appropriate:
-
{relation_name}.connected
The relation is established, but the sdn may not yet have provided any connection or service information. -
{relation_name}.available
the SDN provider has provided its configuration information. The provided information can be accessed via the following methods:sdn-plugin.get_configuration()
For example, a common application for this is configuring an applications SDN configuration, like Kubernetes.
@when('sdn-plugin.available', 'docker.available')
def container_sdn_setup(sdn):
sdn_config = sdn.get_configuration()
with open('/etc/default/docker', 'w') as stream:
stream.write('DOCKER_OPTS=bip={0},mtu={1]}'.format(sdn_config['subnet'], sdn_config['mtu']))
Provides
A charm providing this interface is plugging into its related principal charm.
This interface layer will set the following states, as appropriate:
-
{relation_name}.connected
One or more clients of any type have been related. The charm should call the following methods to provide the appropriate information to the clients:{relation_name}.set_configuration(mtu=mtu, subnet=subnet, cidr=cidr)
Example:
Note, this example will use the Flannel subnet.env file, which has a format like follows:
FLANNEL_NETWORK=10.1.0.0/16
FLANNEL_SUBNET=10.1.8.1/24
FLANNEL_MTU=1410
FLANNEL_IPMASQ=false
And the consuming python code:
@when('flannel.sdn.configured', 'sdn-plugin.connected')
def relay_sdn_configuration(host):
config = hookenv.config()
with open('/var/run/flannel/subnet.env') as f:
flannel_config = f.readlines()
for f in flannel_config:
if "FLANNEL_SUBNET" in f:
value = f.split('=')[-1].strip()
subnet = value
if "FLANNEL_MTU" in f:
value = f.split('=')[1].strip()
mtu = value
host.send_sdn_info(mtu, subnet, hookenv.config('cidr'))
Contact Information
Maintainer
- Charles Butler charles.butler@canonical.com
Etcd
- Flannel home page
- Flannel bug trackers
- Flannel Juju Charm