The Scope Traffic Control plugin allows to modify the performance parameters of container's network interfaces using Weave Scope. The following images show a simple example of how status and controls are displayed in scope UI.

The Scope Traffic Control plugin can be executed stand alone. It will respond to GET /report request on the /var/run/scope/plugins/traffic-control/traffic-control.sock in a JSON format. If the running plugin has been registered by Scope, you will see it in the list of PLUGINS in the bottom right of the UI (see the green rectangle in the above figure).

Note: This plugin requires the sch_netem kernel module.

If you want to make sure of running the latest available version of the plugin, you can pull the image from docker hub.

docker pull weaveworksplugins/scope-traffic-control:latest

To run the Scope Traffic Control plugin you just need to run the following command.

docker run --rm -it \
			 --net=host --pid=host --privileged \
			 -v /var/run:/var/run \
			 --name weaveworksplugins-scope-traffic-control weaveworksplugins/scope-traffic-control:latest

If you want to use the Scope Traffic Control plugin in an already set up Kubernetes cluster with Weave Scope running on it, you just need to run:

kubectl create -f https://github.com/weaveworks-plugins/scope-traffic-control/tree/master/deployments/k8s-traffic-control.yaml

git clone [email protected]:weaveworks-plugins/scope-traffic-control.git
cd scope-traffic-control; make;

The parameters are shown in a table named Traffic Control. The plugin shows the values of latency and packet loss that are enforced on the network interface. The "-" mean that no value is set for that parameter, latency is displayed in milliseconds (ms) and packet loss in percentage.

The Scope Traffic Controls plugin provides a simple interface to change the value of latency (hourglass buttons) and packet loss (scissor button) or remove value that was set (circled cross button). Such buttons are displayed on the top of the container detailed view, just above the STATUS section (See picture below, control are shown inside the green rectangle).

The hourglass buttons control the latency, from left to right they set: 2000ms, 1000ms, and 500ms. The scissor button controls the packet loss, it sets a 10% packet loss. The circled cross button clear any previous settings.