camunda-cloud-worker-send-Telegram-Message

A worker written in JS to fetch and log service tasks from Camunda Cloud and complete them.

Prerequirements ❗

In order to run the worker you need to make sure that a process is deployed to Camunda Cloud, an instance of it has been started and that a service task with the right type is available. You can find the matching process to the worker here as well as all the information how to get an account and how to get the credentials for your worker.

For this worker you need a Telegram Account and you want to make sure you have the app installed either on your phone or desktop. With your account you can then create a Telegrambot. This bot can then sends a message to yourself, to a group or a a channel. Make sure you get the message_id where you want to send it too.

Set up the worker locally

The worker itself, takes the information from the process puts it into a message and then sends it to the Telegram endpoint you have defined with the message ID.

If you want to use the worker, make sure to install all needed packages on your machine

npm i -g typescript ts-node

This package provides functions to connect to Camunda Cloud (Zeebe)

npm i zeebe-node dotenv

This package provides functions to connect to the Telegram API

npm i node-telegram-bot-api

Create a a file .env in the root of the project. Put in there your camunda cloud credentials. You can find more information here Put in there as well your telegram credentials (Telegram_Api_Key and Telegram_Message_ID)

To run the worker open a terminal and use the command:

ts-node src/app.ts

As soon as a task with the type is avaidable the worker will fetch and lock it and then complete it.

If you like to build your own worker from scretch you can follow this tutorial

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Run the worker on Kubernetes in the cloud

If you want to run the worker continuously (in a more realistic environment) it is a good idea not to run it on your machine. To deploy it to Kubernetes on a cloud provider the following steps are needed:

• Create a Docker image. If you want to publish it later on Docker hub make sure to exclude your credentials from the .env as they can be extracted from the docker image later. If you wonder, where to get the credentials check the prerequirmentes on top of this readme
• Publish your Docker image at Docker hub or you can use the image I created for the worker there: https://hub.docker.com/repository/docker/nlea/worker-send-telegram-message
• In order to communicate with Kubernetes make sure you have kubectl installed on your maschine
• For the deployment to Kubernetes the project uses the deploy.yml file which describe a Kubernetes Deployment resource. As the docker image does not contain the credentials, you need to provide them by creating a kubernetes secret

kubectl create secret generic mysecret --from-literal=zeebeaddress
=xxxxx--from-literal=zeebeclientid=xxxxxx--from-literal=zeebeclientsecret=xxxxx--from-literal=zeebeauthorization=xxxxx--from-literal=telegramapikey=xxxxx--from-literal=telegrammessageid=xxxxxx

• Then link it inside the deploy.yml file using Environment Variables. In the deploy.yml you can find in this project the name of the secret is “mysecret”. In the example below you can see how the zeebeaddress is linked in the deploy.yml:

        env: 
        - name: ZEEBE_ADDRESS
          valueFrom:
            secretKeyRef:
              name: mysecret
              key: zeebeaddress

Now you can deploy your Docker image to the Kubernetes cluster 🎉