Nightscout LibreLink Up Uploader/Sidecar

Script written in TypeScript that uploads CGM readings from LibreLink Up to Nightscout. The upload should work with at least Freestyle Libre 2 (FGM) and Libre 3 CGM sensors.

Configuration

The script takes the following environment variables

Variable	Description	Example	Required
LINK_UP_USERNAME	LibreLink Up Login Email	mail@example.com	X
LINK_UP_PASSWORD	LibreLink Up Login Password	mypassword	X
LINK_UP_CONNECTION	LibreLink Up Patient-ID. Can be received from the console output if multiple connections are available.	123456abc-abcd-efgh-7891def
LINK_UP_TIME_INTERVAL	The time interval of requesting values from libre link up	5
LINK_UP_REGION	Your region. Used to determine the correct LibreLinkUp service (Possible values: AE, AP, AU, CA, DE, EU2, EU2, FR, JP, US)	EU
NIGHTSCOUT_URL	Hostname of the Nightscout instance (without https://)	nightscout.yourdomain.com	X
NIGHTSCOUT_API_TOKEN	SHA1 Hash of Nightscout access token	162f14de46149447c3338a8286223de407e3b2fa	X
NIGHTSCOUT_DISABLE_HTTPS	Disables the HTTPS requirement for Nightscout URLs	true
NIGHTSCOUT_DEVICE_NAME	Sets the device name used in Nightscout	nightscout-librelink-up
LOG_LEVEL	The setting of verbosity for logging, should be one of info or debug	info
SINGLE_SHOT	Disables the scheduler and runs the script just once	true
ALL_DATA	Upload all available data from LibreLink Up instead of just data newer than last upload. LibreLinkUp sometimes lags behind in reporting recent historical data, so it is advised to run the script with ALL_DATA set to true at least once a day.	true

Usage

There are different options for using this script.

Variant 1: On Heroku

• Click on
• Login to Heroku if not already happened
• Provide proper values for the environment variables
• Important: make sure that yor Nightscout API token is hashed with SHA1
• Click Deploy to deploy the app

Variant 2: Local

The installation process can be started by running npm install in the root directory.

To start the process simply create a bash script with the set environment variables (start.sh):

#!/bin/bash
export LINK_UP_USERNAME="mail@example.com"
export LINK_UP_PASSWORD="mypassword"
export LINK_UP_TIME_INTERVAL="5"
export NIGHTSCOUT_URL="nightscout.yourdomain.com"
# use `shasum` instead of `sha1sum` on Mac
export NIGHTSCOUT_API_TOKEN=$(echo -n "librelinku-123456789abcde" | sha1sum | cut -d ' ' -f 1)
export LOG_LEVEL="info"

npm start

Execute the script and check the console output.

Variant 3: Docker

The easiest way to use this is to use the latest docker image:

docker run -e LINK_UP_USERNAME="mail@example.com" \
           -e LINK_UP_PASSWORD="mypassword" \
           -e LINK_UP_TIME_INTERVAL="5" \
           -e LINK_UP_REGION="EU" \
           -e NIGHTSCOUT_URL="nightscout.yourdomain.com" \
           -e NIGHTSCOUT_API_TOKEN=$(echo -n "librelinku-123456789abcde" | sha1sum | cut -d ' ' -f 1) \
           -e LOG_LEVEL="info" \
           timoschlueter/nightscout-librelink-up

Variant 4: Docker Compose

If you are already using a dockerized Nightscout instance, this image can be easily added to your existing docker-compose file. In this example, the region is set for germany ("DE"):

version: '3.7'

services:
  nightscout-libre-link:
    image: timoschlueter/nightscout-librelink-up
    container_name: nightscout-libre-link
    environment:
      LINK_UP_USERNAME: "mail@example.com"
      LINK_UP_PASSWORD: "mypassword"
      LINK_UP_TIME_INTERVAL: "5"
      LINK_UP_REGION: "DE"
      NIGHTSCOUT_URL: "nightscout.yourdomain.com"
      NIGHTSCOUT_API_TOKEN: "14c779d01a34ad1337ab59c2168e31b141eb2de6"
      LOG_LEVEL: "info"

Hashing API token

NIGHTSCOUT_API_TOKEN must be a SHA1 hash of an Access Token from Nightscout (Add new subject first in Nightscout's Admin Tools if required), e.g. your Access Token for a subject named LibreLinkUp might be librelinku-123456789abcde.

Obtain your hash with

echo -n "librelinku-123456789abcde" | sha1sum | cut -d ' ' -f 1

(use shasum instead of sha1sum on Mac)

which will print the hash (40 characters in length):

14c779d01a34ad1337ab59c2168e31b141eb2de6

You might also use an online tool to generate your hash, e.g. https://codebeautify.org/sha1-hash-generator

ToDo

• Integration into Nightscout: I have not yet looked into the plugin architecture of Nightscout. Maybe this should be converted into a plugin.