FlashLex SDK 1.4

What is the FlashLex SDK?

The FlashLex SDK is an open source python based client library that you can inetgrate into your own IOT applications. It is intended to run as a service on your thing and provide a local cache for your thing messages.

This guide covers the a few aspects to get up and running with integrating the FlashLex SDK with your IOT application:

  • Installing the FlashLex SDK on your IOT Device

  • Configuring and Bootstraping your IOT Device for FlashLex

  • Creating and Starting The FlashLex service

Installing the FlashLex SDK on your IOT Device

There are 2 ways to install the flashlex client on your IOT device:

  1. Building and Installing the SDK from Github - The SDK is open source so its freely available for download.

  2. Install with pip - Install

For all installations we reccomend using Virtualenv unless you are attempting to build a base image for SD Flashing.

Building and Installing the SDK from Github

The flashlex-sdk is an opensource project that anyone can download or contribute to for free. If you would like you can always install it directly to your device.

git clone https://github.com/claytantor/flashlex-iot-python.git
cd flashlex-iot-python
sudo python setup.py install

Installing from PyPi with pip3

We have a FlashLex dist in PyPi that allows you to use pip3 to install the FlashLex SDK.

pip install flashlexiot

Configuring and Bootstraping your IOT Device for FlashLex

FlashLex runs as a service on your IOT device. It recieves messages over secure transport using MQTT using a topic that is dedicated to the thing. The configuration tells the FlashLex service how to listen to the topic and write messages to local storage. Then your application uses the SDK to get messages from the local store.

sdk architecture

The Service Configuration File

The way that FlashLex runs as a service is with a configuration file. The configuration file has all the information needed for the service to know how to recieve and store messages for the thing (ingress) as well as allow your thing to collect and store messages on the FlashLex cloud (egress).

      endpoint: https://api.flashlex.com
      env: dev
    callback: persistent
    thread: subscribe
    message: This is a really basic message.
      subscriptionData: subscription.json
      expireSeconds: 60 #messages older than an minute
    commitSha: 75ac348aa2ddc249717516d57ff1f03051179625
    id: 349c5942-77d6-4f36-880b-1762a3b07f06
    name: ecd13b11-mything
    endpoint: a1khvirpxw0646-ats.iot.us-east-1.amazonaws.com
      rootCA: root-ca-cert.pem
      cert: ecd13b11-mything-certificate.pem
      privateKey: ecd13b11-mything-keypair-private.pem
      publicKey: ecd13b11-mything-keypair-public.pem
        topic: pubsub/ecd13b11-mything
        topic: ingress/ecd13b11-mything
        topic: flashlex/collect
      useWebsocket: false
      port: 8883
        baseReconnectQuietTimeSecond: 1
        maxReconnectQuietTimeSecond: 30
        stableConnectionTimeSecond: 10
      offlinePublishQueueing: -1
      drainingFrequency: 2
      connectDisconnectTimeout: 60
      mqttOperationTimeout: 120

Running The Bootstrap Application

The bootstrap application, included with your SDK distribution, will allow you to verify that your configuration and and connectivity for your thing to FlashLex is correct and you can start integrating with your application.

python -u bootstrap.py -c keys/config-bootstrap.yml -d $(pwd)/data -k $(pwd)/keys

Creating and Starting The FlashLex service

FlashLex SDK runs as a systemctl service, that allows it to come back up and listen to FlashLex even if the power goes down. It brings an extra level of stability and resiliancy to your IOT device.

Making the systemd service file

The systemd service file is based on your os level and application requirements so we have provided an application that allows you to set specific attributes for the system file pror to copying it and starting the service.


ExecStart={{dir}}/venv/bin/python -u {{dir}}/app.py --config {{dir}}/keys/config.yml


Creating the systemd service

Generic instructions for setting up a service on a Raspberry Pi can be found at https://www.raspberrypi-spy.co.uk/2015/10/how-to-autorun-a-python-script-on-boot-using-systemd/

From the directory that you expanded your distribution to:

sudo cp flashlex.service /lib/systemd/system/flashlex.service
sudo chmod 644 /lib/systemd/system/flashlex.service
sudo systemctl daemon-reload
sudo systemctl enable flashlex.service

Add Logging with syslog

Then, assuming your distribution is using rsyslog to manage syslogs, create a file in /etc/rsyslog.d/<new_file>.conf with the following content:

if $programname == '<your program identifier>' then /path/to/log/file.log
& stop

restart rsyslog (sudo systemctl restart rsyslog) and enjoy! Your program stdout/stderr will still be available through journalctl (sudo journalctl -u <your program identifier>) but they will also be available in your file of choice.

sudo cp flashlex.conf /etc/rsyslog.d/flashlex.conf
sudo systemctl daemon-reload
sudo systemctl restart flashlex.service
sudo systemctl restart rsyslog

you will want to rotate logs so your disk doesnt fill up with logs. your conf file for logrotation looks like this in /etc/logrotate.conf:

/var/log/flashlex.log {
    rotate 7
    maxage 7

make a crontab that executes logrotate daily

/usr/sbin/logrotate /etc/logrotate.conf