TWAMP Client

TWAMP Client is a part of IP probe solution based on perfSONAR project. Whole probe is modular microservice solution based on docker containers. Client part is designed as stanalone solution with no requiremet for any external input connection. The configuration of the client which includes global configuration and list of IP addresses is periodicaly downloded from central side.

Prerequisits

Installation of Docker with docker compose plugin is necessary on host machine.

Operation tests

The whole solution has been tested on ARMv7 (RPi) and AMD64 architecture (Desktop PC).

Building

Almost everything is automated via docker compose. You just need to download the project and run docker compose build.

git clone https://github.com/saidlm/twamp_client
cd twamp_client
docker compose build

Configuration

The input for docker compose is split into two files - docker-mpose.yml and docker-compose.override.yml. It is done due to provisioning automation. Common container configuration is stored in docker-compose.yml but everything which is site specific is a part of docker-compose.override.yml file. Site specific configuration can be easily generated during provisioning of the probe base on database data by ansible or any other automated solution. Everything else is same for all network sites.

Container configuration

• Create volume
• Change storage path in docker-compose.yml
• Change hostname of client container (if necessary) in docker-compose.yml. The hostname is used as data source identification for metrics.
• Basic configuration will be automaticaly populated during the first run; three new directovy will be created on your volume - bin/ cron.d/ and data/
• Change URL and credentioal of config site in data/global_config.json in "ConfigSource" section.
• Change crontabs according your needs if necessary

Directory structure

Directory	Description
bin	Executable scripts
cron.d	Crontabs
data	Dynamic configs downloaded from central site

Configuration files

File Name	Description
cron.d/probe	Crontab defining probe time cycle
cron.d/twamp_config_downloader	Crontab for config downloader
data.d/twamp_global_config.json	Basic global configuration; it will be overwrited after the first start by newly downloaded configuration file.

Twamp client configuration

• Only update of the configuration files is possible in current version of the client container. The plan is to have possibility to update almost whole container functionality from central site in defined time interval at the end of the day.
• There must be at least two files stored on URL configured in the section "ConfigSource" of twamp_global_config file - twamp_global_config.json and twamp_targets_list.json
• The examples of configuration files are in config_example directory of the project.
• There are two method how to download configuration files from central site. The method can be configured in main config file it can be 'web' or 'git'.

twamp_global_config.json

There are two section for current version of client container:

Section	Description
ConfigSource	Define URL and credentials for configuration downloader
Destination	Define URL and passphrase for message colector (telegraf)

ConfigURL section parameters are different for git and web method. Configuration for git method:

Parameter	Description
ConfigMethod	git
ConfigURL	Git URL where configuration files are stored. Username and password is is part of URL in standard form

Configuration for web method:

Parameter	Description
ConfigMethod	web
ConfigURL	URL where configuration files are stored
ConfigUser	User
ConfigPassword	Password

Destination section parameters are:

Parameter	Description
DestinationURL	URL of telegraf collector
DestinationPassword	Passphrase for telegraf collector in MD5 hash form

twamp_targets_list.json

There is currently only one section - Targets. It includes array of targets' (twamp responders') parameters.

Parameter	Description
IP	IP address or DNS name of the twamp responder
DSCP	DSCP mark for the test packet header
Custom_comment	Comment string which is part of metric message

Running

Create new container and start it:

PROBE_PREFIX=<probe_prefix> docker compose up -d

Network ports

There is no ports exposed outside of container.