cohydra.node.lxd

LXD containers in the simulation.

Functions

log_to_file

Log the container’s output.

Classes

LXDNode

A LXDNode represents a LXD container.

cohydra.node.lxd.log_to_file(container, log_path, stdout=False, stderr=False)[source]

Log the container’s output.

This opens a stream to the docker container’s log output and writes it into a file.

Parameters

  • log_path (str) – The file path to the log file.

  • stdout (bool) – Whether stdout should be logged.

  • stderr (bool) – Whether stderr should be logged.

class cohydra.node.lxd.LXDNode(name, image=None, image_server='https://images.linuxcontainers.org', custom_configuration=None)[source]

Bases: cohydra.node.base.Node

A LXDNode represents a LXD container.

Parameters

  • name (str) – The name of the node (and container).

  • image (str) – The name of the image to use (=the alias).

  • image_server (str) – The server to pull the image off if not found locally.

  • custom_configuration (dict) – Additional configuration key-value-pairs to pass to LXD.

image = None

The image’s name being used.

container = None

The container instance.

custom_configuration = None

Custom configuration values.

command_executor = None

The executor for running commands in the container. This is useful for a scripted Workflow.

image_server = None

The server to fetch the image from. Before fetching from the server, local images will be checked.

wants_ip_stack()[source]

Indicates whether a IP stack shall be installed onto the node.

Installing is handled by the Channel.

Returns

True indicates that a ns-3 IP stack shall be installed when preparing this node.

Return type

bool

prepare(simulation)[source]

This runs a setup on network interfaces and starts the container.

create_container()[source]

Create the LXC container.

start_container(log_directory, hosts=None)[source]

Start the LXC container.

All docker containers are labeled with “ns-3” as the creator.

Parameters

  • log_directory (str) – The path to the directory to put log files in.

  • hosts (dict) – A dictionary with hostnames as keys and IP addresses (a list) as value.

delete_container()[source]

Delete the container.

setup_host_interfaces()[source]

Setup the interfaces (bridge, tap, VETH pair) on the host and connect them to the container.

add_interface(interface, name=None, prefix='eth')

Add an interface to the node.

Warning: Do not call this function manually.

The functionality is handled by the network and channels.

Parameters

  • interface (Interface) – The interface to add.

  • name (str) – The name of the interface.

  • prefix (str) – If no name is supplied, the function works out a name by appending a number to the prefix.

execute_command(command, user=None)

Execute a command within the node.

Parameters

  • command (str or list of str) – The command to execute.

  • user (str) – If a user (name) is specified, the command is executed as this user. Warning: Not all nodes support this feature.

go_offline()

Disconnect the node from all channels.

go_online()

Connect the node back to all channels.

set_position(x, y, z=0)

Set the position of the node and updates the mobitlity model.

Parameters

  • x (float) – The x-position.

  • y (float) – The y-position.

  • z (float) – The z-position.

Inheritance Diagramm

Inheritance diagram of cohydra.node.lxd