dbainbri-ciena / letmein

Let Me In

This container is used with a VOLTHA deployment that leverages an OVS switch to enable upstream communication with a back end DHCP and/or IGMP system.

Description

This container does a synchronization between ONOS and the managed OVS switch. It polls the device information from ONOS and evaluates the accessDevice object under each device entry. From the accessDevice object it collects the vlan values.

The container then queries the flows on the managed OVS switch, which it created as identified by the appId associated with the flow. The existing flows are evaluated to understand if there exists the required flow for each VLAN. If there exists a rule that is no longer needed, it is deleted.

Finally, for those VLANs for which there is no existing rule a new flow rule is POSTed to ONOS.

The Rule

The rule POSTed to ONOS does a packet in to ONOS for traffic that arrives on on port 1 and and matches the VLAN ID of those discovered from the ONOS network configuration. The rule is generated from the following template file:

{
    "priority": 32768,
    "appId" : "{{.AppId}}",
    "timeout": 0,
    "isPermanent": true,
    "deviceId": "{{.DPID}}",
    "treatment": {
        "instructions": [
            {
                "type": "OUTPUT",
                "port": "CONTROLLER"
            }
        ]
    },
    "selector": {
        "criteria": [
            {
                "type": "IN_PORT",
                "port": "1"
            },
            {
                "type": "VLAN_VID",
                "vlanId": "{{.VlanId}}"
            }
        ]
    }
}

configuration

This container is configured via environment variables

KEY	VALUE	DESCRIPTION
ONOS_CONNECT_URL	http://karaf:karaf@onos:8181	URL with which to connect to ONOS
OVS_DPID	:discover	DPID of switch to manager
OVS_PORT	:discover	Port on OVS switch to provision
CREATE_FLOW_TEMPLATE	/var/templates/create.tmpl	Template file used to create flow rule in ONOS
INTERVAL	30s	Frequency to check for correct flows
VERIFY	false	When true, just log changes that would be made, but don't make changes
LOG_LEVEL	info	detail level for logging
LOG_FORMAT	text	log output format, text or json

The value :discover for the options OVS_DPID and OVS_PORT is used to indicate to the container that heuristics should be used to identify the OVS switch and its port in ONOS. The heuristics used are:

• OVS_DPID - based on the device attributes, as queried from ONOS, the first switch found where the "hw" value is "Open vSwitch", the "driver" value is "ovs", and the device is "available" is selected.
• OVS_PORT - based on the port attributes, as queried from ONOS, the first port on the selected switch where the port is not "local" and it is "enabled" is selected.