Control OpenHab using Telegram Messenger

Recently, I've been trying to discover a way to control my OpenHab instance using Google Assistant.
It is rather easy to do this using IFTTT, but only when You use OpenHab in a cloud.
I prefer using private instalation of OpenHab in my LAN, so that was not an option for me. I was searching for another solution, but only app supported by IFTTT which might be usefull form me was Telegram messenger. The only problem is, that OpenHab does not support Telegram controling by default.
I google'd a little and it turned out that Telegram has a great public API with good Java support, so I decided to write a simple Spring Boot application as a bridge between Telegram Bot and OpenHab instance.
You can find source code of my application on my GitHub account:

https://github.com/aogorek/openhabtelegrambot

In order to run it there are few steps required:

1. Create Bot in Telegram Messenger

First You have to create Your own bot to communicate with. You need to contact @BotFather to do this. BotFather is a special Telegram bot used to control all Your bots.

To contact him go to this link:

https://telegram.me/BotFather

Here is sample conversation with bot, to receive token required to contact Your new bot:

Your API token should be protected properly. Everybody who will gain access to this API token, will have access to control your OpenHab, so be warned :).

2. Build and run TelegramBot application

Next step is to download and build application from my GitHub. You need to have maven, GIT and java installed.

So type:

#git clone https://github.com/aogorek/openhabtelegrambot.git
#cd openhabtelegrambot/
#mvn clean install

After build completion, telegrambot-x.x.x-SNAPSHOT.jar should be present in target folder.

Then You need to prepare properties file. It is not present in jar, because it should contain Api Key, and as I wrote before it should be protected.

So, let's create application.properties file with that content:

#name of your bot created with BotFather
botUserName=my_private_openhab_bot
#Private API token for bot, received from BotFather
botToken=xxxxxxx:xxxxxxxxxxxxxxxxxxxxxxxxx
#URL of Your OpenHab instance. 

openHabURL=http://192.168.1.8:8080

You should copy target jar file to destination folder, then create subfolder 'config' and put application.properties in it.

Jar is executable, so in destination folder type :

./telegrambot-x.x.x-SNAPSHOT.jar

Instructions are for Linux, but on Windows and Mac it should be very similar.

And that's it. You can control OpenHab using chat with your newly created bot.

3. Install app as a service (optional)

I use Raspberry Pi, so It was convenient for me to start my app as a service everytime machine boots.

In order to do this You need these steps  (should work with other Linux distros too):

#sudo mkdir /var/telegrambot
#sudo mkdir /var/telegrambot/config

copy application.properties to /var/telegrambot/config
copy telegrambot.jar to /var/telegrambot

Go to folder

/etc/systemd/system

and create file

telegrambot.service

with content:

[Unit]
Description=telegrambot
After=syslog.target

[Service]
User=telegrambot
ExecStart=/var/telegrambot/telegrambot.jar
SuccessExitStatus=143

[Install]
WantedBy=multi-user.target

call command:

#systemctl daemon-reload

and

#service telegrambot start


That's it... App should work.

4. Use Bot to control OpenHab

Currently there are four command supported.

EDIT: 
 I added another commands: CHART and STATE

Go to Bot Chat window, type HELP, and feel free to have a lot of fun :).
Take a look how it works in real life :)

5. What next

My application is easily extendable, so it is possible to add new commands quite fast. Feel free to fork my sourcecode end experiment with it. If You will be interested in further improvements, leave me a note, so I will prepare a tutorial how to implement new functionalities.

When we have working Telegram control, it is easy to connect it with IFTTT and use Google Assistant with voice activation, but this is a topic for next post.

Any feedback appreciated :)