core-extra/docs/grpc.md

gRPC API

• Table of Contents {:toc}

gRPC is a client/server API for interfacing with CORE and used by the python GUI for driving all functionality. It is dependent on having a running core-daemon instance to be leveraged.

A python client can be created from the raw generated grpc files included with CORE or one can leverage a provided gRPC client that helps encapsulate some of the functionality to try and help make things easier.

Python Client

A python client wrapper is provided at CoreGrpcClient to help provide some conveniences when using the API.

Client HTTP Proxy

Since gRPC is HTTP2 based, proxy configurations can cause issues. By default the client disables proxy support to avoid issues when a proxy is present. You can enable and properly account for this issue when needed.

Proto Files

Proto files are used to define the API and protobuf messages that are used for interfaces with this API.

They can be found here to see the specifics of what is going on and response message values that would be returned.

Examples

Node Models

When creating nodes of type NodeType.DEFAULT these are the default models and the services they map to.

• mdr
  • zebra, OSPFv3MDR, IPForward
• PC
  • DefaultRoute
• router
  • zebra, OSPFv2, OSPFv3, IPForward
• host
  • DefaultRoute, SSH

Interface Helper

There is an interface helper class that can be leveraged for convenience when creating interface data for nodes. Alternatively one can manually create a core.api.grpc.wrappers.Interface class instead with appropriate information.

Manually creating gRPC client interface:

from core.api.grpc.wrappers import Interface
# id is optional and will set to the next available id
# name is optional and will default to eth<id>
# mac is optional and will result in a randomly generated mac
iface = Interface(
    id=0,
    name="eth0",
    ip4="10.0.0.1",
    ip4_mask=24,
    ip6="2001::",
    ip6_mask=64,
)

Leveraging the interface helper class:

from core.api.grpc import client

iface_helper = client.InterfaceHelper(ip4_prefix="10.0.0.0/24", ip6_prefix="2001::/64")
# node_id is used to get an ip4/ip6 address indexed from within the above prefixes
# iface_id is required and used exactly for that
# name is optional and would default to eth<id>
# mac is optional and will result in a randomly generated mac
iface_data = iface_helper.create_iface(
    node_id=1, iface_id=0, name="eth0", mac="00:00:00:00:aa:00"
)

Listening to Events

Various events that can occur within a session can be listened to.

Event types:

• session - events for changes in session state and mobility start/stop/pause
• node - events for node movements and icon changes
• link - events for link configuration changes and wireless link add/delete
• config - configuration events when legacy gui joins a session
• exception - alert/error events
• file - file events when the legacy gui joins a session

from core.api.grpc import client
from core.api.grpc.wrappers import EventType

def event_listener(event):
    print(event)

# create grpc client and connect
core = client.CoreGrpcClient()
core.connect()

# add session
session = core.create_session()

# provide no events to listen to all events
core.events(session.id, event_listener)

# provide events to listen to specific events
core.events(session.id, event_listener, [EventType.NODE])

Configuring Links

Links can be configured at the time of creation or during runtime.

Currently supported configuration options:

• bandwidth (bps)
• delay (us)
• duplicate (%)
• jitter (us)
• loss (%)

from core.api.grpc import client
from core.api.grpc.wrappers import LinkOptions, Position

# interface helper
iface_helper = client.InterfaceHelper(ip4_prefix="10.0.0.0/24", ip6_prefix="2001::/64")

# create grpc client and connect
core = client.CoreGrpcClient()
core.connect()

# add session
session = core.create_session()

# create nodes
position = Position(x=100, y=100)
node1 = session.add_node(1, position=position)
position = Position(x=300, y=100)
node2 = session.add_node(2, position=position)

# configuring when creating a link
options = LinkOptions(
    bandwidth=54_000_000,
    delay=5000,
    dup=5,
    loss=5.5,
    jitter=0,
)
iface1 = iface_helper.create_iface(node1.id, 0)
iface2 = iface_helper.create_iface(node2.id, 0)
link = session.add_link(node1=node1, node2=node2, iface1=iface1, iface2=iface2)

# configuring during runtime
link.options.loss = 10.0
core.edit_link(session.id, link)

Peer to Peer Example

# required imports
from core.api.grpc import client
from core.api.grpc.core_pb2 import Position

# interface helper
iface_helper = client.InterfaceHelper(ip4_prefix="10.0.0.0/24", ip6_prefix="2001::/64")

# create grpc client and connect
core = client.CoreGrpcClient()
core.connect()

# add session
session = core.create_session()

# create nodes
position = Position(x=100, y=100)
node1 = session.add_node(1, position=position)
position = Position(x=300, y=100)
node2 = session.add_node(2, position=position)

# create link
iface1 = iface_helper.create_iface(node1.id, 0)
iface2 = iface_helper.create_iface(node2.id, 0)
session.add_link(node1=node1, node2=node2, iface1=iface1, iface2=iface2)

# start session
core.start_session(session)

Switch/Hub Example

# required imports
from core.api.grpc import client
from core.api.grpc.core_pb2 import NodeType, Position

# interface helper
iface_helper = client.InterfaceHelper(ip4_prefix="10.0.0.0/24", ip6_prefix="2001::/64")

# create grpc client and connect
core = client.CoreGrpcClient()
core.connect()

# add session
session = core.create_session()

# create nodes
position = Position(x=200, y=200)
switch = session.add_node(1, _type=NodeType.SWITCH, position=position)
position = Position(x=100, y=100)
node1 = session.add_node(2, position=position)
position = Position(x=300, y=100)
node2 = session.add_node(3, position=position)

# create links
iface1 = iface_helper.create_iface(node1.id, 0)
session.add_link(node1=node1, node2=switch, iface1=iface1)
iface1 = iface_helper.create_iface(node2.id, 0)
session.add_link(node1=node2, node2=switch, iface1=iface1)

# start session
core.start_session(session)

WLAN Example

# required imports
from core.api.grpc import client
from core.api.grpc.core_pb2 import NodeType, Position

# interface helper
iface_helper = client.InterfaceHelper(ip4_prefix="10.0.0.0/24", ip6_prefix="2001::/64")

# create grpc client and connect
core = client.CoreGrpcClient()
core.connect()

# add session
session = core.create_session()

# create nodes
position = Position(x=200, y=200)
wlan = session.add_node(1, _type=NodeType.WIRELESS_LAN, position=position)
position = Position(x=100, y=100)
node1 = session.add_node(2, model="mdr", position=position)
position = Position(x=300, y=100)
node2 = session.add_node(3, model="mdr", position=position)

# create links
iface1 = iface_helper.create_iface(node1.id, 0)
session.add_link(node1=node1, node2=wlan, iface1=iface1)
iface1 = iface_helper.create_iface(node2.id, 0)
session.add_link(node1=node2, node2=wlan, iface1=iface1)

# set wlan config using a dict mapping currently
# support values as strings
wlan.set_wlan(
    {
        "range": "280",
        "bandwidth": "55000000",
        "delay": "6000",
        "jitter": "5",
        "error": "5",
    }
)

# start session
core.start_session(session)

EMANE Example

For EMANE you can import and use one of the existing models and use its name for configuration.

Current models:

• core.emane.ieee80211abg.EmaneIeee80211abgModel
• core.emane.rfpipe.EmaneRfPipeModel
• core.emane.tdma.EmaneTdmaModel
• core.emane.bypass.EmaneBypassModel

Their configurations options are driven dynamically from parsed EMANE manifest files from the installed version of EMANE.

Options and their purpose can be found at the EMANE Wiki.

If configuring EMANE global settings or model mac/phy specific settings, any value not provided will use the defaults. When no configuration is used, the defaults are used.

# required imports
from core.api.grpc import client
from core.api.grpc.core_pb2 import NodeType, Position
from core.emane.ieee80211abg import EmaneIeee80211abgModel

# interface helper
iface_helper = client.InterfaceHelper(ip4_prefix="10.0.0.0/24", ip6_prefix="2001::/64")

# create grpc client and connect
core = client.CoreGrpcClient()
core.connect()

# add session
session = core.create_session()

# create nodes
position = Position(x=200, y=200)
emane = session.add_node(
    1, _type=NodeType.EMANE, position=position, emane=EmaneIeee80211abgModel.name
)
position = Position(x=100, y=100)
node1 = session.add_node(2, model="mdr", position=position)
position = Position(x=300, y=100)
node2 = session.add_node(3, model="mdr", position=position)

# create links
iface1 = iface_helper.create_iface(node1.id, 0)
session.add_link(node1=node1, node2=emane, iface1=iface1)
iface1 = iface_helper.create_iface(node2.id, 0)
session.add_link(node1=node2, node2=emane, iface1=iface1)

# setting global emane configuration
session.set_emane({"eventservicettl": "2"})
# setting emane specific emane model configuration
emane.set_emane_model(EmaneIeee80211abgModel.name, {"unicastrate": "3"})

# start session
core.start_session(session)

EMANE Model Configuration:

# emane network specific config, set on an emane node
# this setting applies to all nodes connected
emane.set_emane_model(EmaneIeee80211abgModel.name, {"unicastrate": "3"})

# node specific config for an individual node connected to an emane network
node.set_emane_model(EmaneIeee80211abgModel.name, {"unicastrate": "3"})

# node interface specific config for an individual node connected to an emane network
node.set_emane_model(EmaneIeee80211abgModel.name, {"unicastrate": "3"}, iface_id=0)

Configuring a Service

Services help generate and run bash scripts on nodes for a given purpose.

Configuring the files of a service results in a specific hard coded script being generated, instead of the default scripts, that may leverage dynamic generation.

The following features can be configured for a service:

• files - files that will be generated
• directories - directories that will be mounted unique to the node
• startup - commands to run start a service
• validate - commands to run to validate a service
• shutdown - commands to run to stop a service

Editing service properties:

# configure a service, for a node, for a given session
node.service_configs[service_name] = NodeServiceData(
    configs=["file1.sh", "file2.sh"],
    directories=["/etc/node"],
    startup=["bash file1.sh"],
    validate=[],
    shutdown=[],
)

When editing a service file, it must be the name of config file that the service will generate.

Editing a service file:

# to edit the contents of a generated file you can specify
# the service, the file name, and its contents
file_configs = node.service_file_configs.setdefault(service_name, {})
file_configs[file_name] = "echo hello world"

File Examples

File versions of the network examples can be found here. These examples will create a session using the gRPC API when the core-daemon is running.

You can then switch to and attach to these sessions using either of the CORE GUIs.