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Local Emulation

You can create custom topologies and run locally with Containernet using the FogbedExperiment class.

topology.py
from fogbed import Container, FogbedExperiment

exp   = FogbedExperiment()
cloud = exp.add_virtual_instance('cloud')
edge  = exp.add_virtual_instance('edge')

d1 = Container('d1')
d2 = Container('d2')
exp.add_docker(container=d1, datacenter=cloud)
exp.add_docker(container=d2, datacenter=edge)

exp.add_link(cloud, edge, delay='50ms')

try:
    exp.start()
    print(d1.cmd(f'ping -c 4 {d2.ip}'))

except Exception as ex:
    print(ex)
finally:
    exp.stop()

Limiting CPU and Memory

from fogbed import FogbedExperiment

exp = FogbedExperiment(max_cpu=0.5, max_memory=512)
  • max_cpu - sets the maximum percentage of CPU usage that can be consumed by the emulation.
  • max_memory - defines the maximum amount of memory in megabytes that the emulation can utilize.

Setting a Resource Model

Each VirtualInstance has an optional resource_model param that defines how many resources that instance have. 

from fogbed import (
    FogbedExperiment, Container, CloudResourceModel, EdgeResourceModel
)

exp   = FogbedExperiment()
cloud = exp.add_virtual_instance('cloud', resource_model=CloudResourceModel(max_cu=8.0, max_mu=1024))
edge  = exp.add_virtual_instance('edge', resource_model=EdgeResourceModel(max_cu=2.0, max_mu=256))

  • resource_model - If defined, Fogbed enables the limiting resources feature on containers.

Adding or removing containers in runtime

from fogbed import Container, FogbedExperiment
...

try:
    exp.start()
    ...

    exp.add_docker(container=Container('d3'), datacenter=edge)
    print(exp.get_docker('d3').cmd(f'ping -c 4 {d1.ip}'))
    exp.remove_docker('d3')

except Exception as ex:
    print(ex)
finally:
    exp.stop()

Helper methods

The FogbedExperiment class offers some helper methods like:

add_docker (container: Container, datacenter: VirtualInstance)

  • Adds a container to a virtual instance.
  • Raises a ContainerAlreadyExists exception if name or ip already exists.

add_link (node1: VirtualInstance, node2: VirtualInstance, **params: Any)

  • Adds a link between two virtual instances.

add_virtual_instance (name: str, resource_model: Optional[ResourceModel] = None) -> VirtualInstance

  • Creates a virtual instance.
  • Raises a VirtualInstanceAlreadyExists exception if name already exists.

get_containers () -> List[Container]

  • Returns all containers of the emulation.

get_docker (name: str) -> Container

  • Returns a container by name.
  • Raises a ContainerNotFound exception if name doesn't exist.

get_virtual_instance (name: str) -> VirtualInstance

  • Returns a virtual instance by name.
  • Raises a VirtualInstanceNotFound exception if name doesn't exist.

get_virtual_instances () -> List[VirtualInstance]

  • Returns all virtual instances of the emulation.

remove_docker (name: str)

  • Removes a container by name.
  • Raises a ContainerNotFound exception if name doesn't exist.

start_cli ()

  • Starts the Containernet Command Line Interface.

start ()

  • Starts the experiment.

stop ()

  • Stops the experiment.