marvis.node.docker

Docker containers in the simulation.

Functions

`expand_volume_shorthand`	Expand a volume string to something the Docker runtime understands.
`log_to_file`	Log the container's output.

Classes

DockerNode

A DockerNode represents a docker container.

marvis.node.docker.expand_volume_shorthand(key_value)[source]

Expand a volume string to something the Docker runtime understands.

Parameters: key_value (str or dict) – The volume configuration
Returns: Return the volume’s name / path and a settings dictionary.
Return type: tuple

marvis.node.docker.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 marvis.node.docker.DockerNode(name, docker_image=None, docker_build_dir=None, dockerfile='Dockerfile', pull=False, cpus=0.0, memory=None, devices=None, command=None, volumes=None, exposed_ports=None, environment_variables=None)[source]

Bases: marvis.node.base.Node

A DockerNode represents a docker container.

Parameters

name (str) – The name of the node (and container). It must consist only of alphanumeric characters and -, _ and ..
docker_image (str) – The name of the docker image to use. If not specified, docker_build_dir must be set.
docker_build_dir (str) – The context directory (absolute or relative) to execute the build in.
dockerfile (str, default: ‘Dockerfile’) – The (absolute or relative) path to the Dockerfile.
pull (bool) – Whether to always pull the image specified in docker_image.
cpus (float) – The number of virtual CPUs to assign (1.0 meaning 1 vCPU).
memory (str) – The amount of memory to allow the container to use. Example: ‘128m’.
devices (list) – Devices that should be attached to the container. Example: /dev/ttyUSB0:/dev/ttyUSB0.
command (str) – An optional command to override the standard command on container start specified by the Dockerfile.
volumes (list of dict or list of str) – A dictionary of volumes. Each entry has a name or (absolute) path as key and settings or a absolute path inside the container as value. See examples/volumes_and_ports.py.
exposed_ports (dict) – A dictionary of port mappings. The key is the container internal port and the value can be an exposed port or a list of ports.
environment_variables (dict or list) – A dictonary of environment variables or a list of environment variables. If a list is specified each item should be in the form 'KEY=VALUE'.

docker_image: The docker image to use.

docker_build_dir: The context to build the image in.

dockerfile: The path to the Dockerfile.

pull: Enforce pulling the image from a registry

cpus: The number of vCPUs.

memory: The amount of memory for the container.

devices: List of devices to attach to container

command: The startup command.

volumes: The volumes for the container.

exposed_ports: Ports to expose on the host.

environment_variables: Environment variables in the container.

container: The container instance.

container_pid: The PID of the container.

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

property docker_image_tag

A tag for the container’s image during build time.

Returns: The computed tag.
Return type: str

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.

build_docker_image()[source]: Build the image for the container.

start_docker_container(log_directory, hosts=None)[source]

Start the docker 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.

stop_docker_container()[source]: Stop 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.

channels: The cannels the node is connected to.

name: The name of the node.

ns3_node: The ns-3 internal node.

position: The position of the node (used by wifi models and visualization)

color: The color of the node used in the visualization.

interfaces: The interfaces (~network cards) of this node.

Inheritance Diagramm