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August 17, 2023 08:40
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Using pumba/netem to set link impairments for container links
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| #!/usr/bin/env bash | |
| # Copyright 2023 Nokia | |
| # Licensed under the BSD 3-Clause License. | |
| # SPDX-License-Identifier: BSD-3-Clause | |
| # this is an example of a bash script that can be used to introduce network impairments | |
| set -o errexit | |
| set -o pipefail | |
| # change this to your own lab name (this is clab-<labname>) | |
| LAB_NAME="clab-netem" | |
| # default values, overridden by command-line arguments | |
| cmd="" # command to be executed, one of [delay] | |
| node="" | |
| interface="" | |
| time="100" # default time delay is 100ms | |
| jitter="" | |
| correlation="" | |
| distribution="" | |
| percent="0" | |
| duration="8760h" # 1 year duration by default | |
| rate="100kbit" # default rate limiting is 100kbit | |
| # ----------------------------------------------------------------------------- | |
| # Helper functions. | |
| # ----------------------------------------------------------------------------- | |
| # usage examples | |
| DELAY_USAGE="Usage: ./netem.sh delay -n <container name without lab prefix> -i <inteface-name> [-t <delay in ms>] [-d <impairment duration with ms/s/m/h suffix (default is 8760h)>] [-j <jitter in ms>] [-c <correlation>] [-r <distribution>]" | |
| LOSS_USAGE="Usage: ./netem.sh delay -n <container name without lab prefix> -i <inteface-name> [-p <loss percent>] [-c <correlation>]" | |
| RATE_USAGE="Usage: ./netem.sh delay -n <container name without lab prefix> -i <inteface-name> [-r <rate in kbit>]" | |
| # Read command-line arguments | |
| while [[ $# -gt 0 ]]; do | |
| case "$1" in | |
| -n|--node) | |
| node="$2" | |
| shift 2 | |
| ;; | |
| -i|--interface) | |
| interface="$2" | |
| shift 2 | |
| ;; | |
| -t|--time) | |
| time="$2" | |
| shift 2 | |
| ;; | |
| -j|--jitter) | |
| jitter="$2" | |
| shift 2 | |
| ;; | |
| -c|--correlation) | |
| correlation="$2" | |
| shift 2 | |
| ;; | |
| -r|--distribution) | |
| distribution="$2" | |
| shift 2 | |
| ;; | |
| -p|--percent) | |
| percent="$2" | |
| shift 2 | |
| ;; | |
| -d|--duration) | |
| duration="$2" | |
| shift 2 | |
| ;; | |
| -r|--rate) | |
| rate="$2" | |
| shift 2 | |
| ;; | |
| delay) | |
| cmd="delay" | |
| shift 1 | |
| ;; | |
| loss) | |
| cmd="loss" | |
| shift 1 | |
| ;; | |
| rate) | |
| cmd="rate" | |
| shift 1 | |
| ;; | |
| stop-all) | |
| cmd="stop-all" | |
| shift 1 | |
| ;; | |
| *) | |
| echo "Unknown flag: $1" | |
| exit 1 | |
| ;; | |
| esac | |
| done | |
| # ----------------------------------------------------------------------------- | |
| # netem functions. | |
| # Allowed to be customized by a user. | |
| # ----------------------------------------------------------------------------- | |
| # introduce a delay on a selected link for a selected container | |
| function delay { | |
| check-mandatory-parameters ${DELAY_USAGE} | |
| handle_optional_parameters | |
| echo "Starting delay function for node \"${node}:${interface}\" with time=${time}ms ${JITTER_ECHO} ${CORRELATION_ECHO} ${DISTRIBUTION_ECHO}" | |
| sudo docker run -d --name netem-${LAB_NAME}-${RANDOM} -it --rm -v /var/run/docker.sock:/var/run/docker.sock gaiaadm/pumba \ | |
| netem --tc-image ghcr.io/srl-labs/iproute2 --duration ${duration} --interface ${interface} \ | |
| delay --time ${time} \ | |
| ${JITTER_FLAGS} ${CORRELATION_FLAGS} ${DISTRIBUTION_FLAGS} \ | |
| ${LAB_NAME}-${node} > /dev/null | |
| } | |
| # introduce a packet loss on a selected link for a selected container | |
| function loss { | |
| check-mandatory-parameters ${LOSS_USAGE} | |
| handle_optional_parameters | |
| echo "Starting loss function for node \"${node}:${interface}\" with percent=${percent}% ${CORRELATION_ECHO}" | |
| sudo docker run -d --name netem-${LAB_NAME}-${RANDOM} -it --rm -v /var/run/docker.sock:/var/run/docker.sock gaiaadm/pumba \ | |
| netem --tc-image ghcr.io/srl-labs/iproute2 --duration ${duration} --interface ${interface} \ | |
| loss --percent ${percent} \ | |
| ${CORRELATION_FLAGS} \ | |
| ${LAB_NAME}-${node} > /dev/null | |
| } | |
| # introduce a an egress rate limit on a selected link for a selected container | |
| function rate { | |
| check-mandatory-parameters ${RATE_USAGE} | |
| handle_optional_parameters | |
| echo "Starting rate function for node \"${node}:${interface}\" with rate=${rate}" | |
| sudo docker run -d --name netem-${LAB_NAME}-${RANDOM} -it --rm -v /var/run/docker.sock:/var/run/docker.sock gaiaadm/pumba \ | |
| netem --tc-image ghcr.io/srl-labs/iproute2 --duration ${duration} --interface ${interface} \ | |
| rate --rate ${rate} \ | |
| ${LAB_NAME}-${node} > /dev/null | |
| } | |
| # remove all network emulation containers effectively stopping all link impairments | |
| # started by this script. | |
| function stop-all { | |
| sudo docker ps -a -q -f name="netem-${LAB_NAME}" | xargs -n1 sudo docker stop | |
| } | |
| function check-mandatory-parameters { | |
| if [[ -z $node ]]; then | |
| echo "Error: Node is not set or empty.\nUsage: $1" | |
| exit 1 | |
| fi | |
| if [[ -z $interface ]]; then | |
| echo "Error: Node is not set or empty.\nUsage: $1" | |
| exit 1 | |
| fi | |
| } | |
| # handling optional parameters | |
| function handle_optional_parameters { | |
| if [[ ! -z $jitter ]]; then | |
| JITTER_FLAGS="--jitter ${jitter}" # flag/value to append to the command | |
| JITTER_ECHO="jitter=${jitter}ms" # echo to print | |
| fi | |
| if [[ ! -z $correlation ]]; then | |
| CORRELATION_FLAGS="--correlation ${correlation}" | |
| CORRELATION_ECHO="correlation=${correlation}" | |
| fi | |
| if [[ ! -z $distribution ]]; then | |
| DISTRIBUTION_FLAGS="--distribution ${distribution}" | |
| DISTRIBUTION_ECHO="distribution=${distribution}" | |
| fi | |
| } | |
| # invoke the command | |
| ${cmd} | |
| # ----------------------------------------------------------------------------- | |
| # Bash runner functions. | |
| # ----------------------------------------------------------------------------- | |
| function help { | |
| printf "%s <task> [args]\n\nTasks:\n" "${0}" | |
| compgen -A function | grep -v "^_" | cat -n | |
| printf "\nExtended help:\n Each task has comments for general usage\n" | |
| } |
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