NUT

Repository contains the NUT configuration and tells how to install Docker, Docker Compose and run the Home Assistant as a Docker container. Additionally I present how to turn off the Mikrotik router from the Raspberry Pi if the battery level state is low.

I decided to "promote" this video that is just an excellent example that explains step by step how to install and configure NUT on a Raspberry Pi. Network UPS Tools (NUT Server) Ultimate Guide.

1. First run the lsusb command

It will allow you to find out what device is connected through the USB port.

2. Then perform the below command to update repositories:

sudo apt update

3. Then we are going to install the NUT, NUT client and NUT server

sudo apt install nut nut-client nut-server

4. Next you can use a utility called a nut scanner to actually probe the UPS device and get some information from it so you can configure it a little bit easier.

sudo nut-scanner -U

You can see the result, so you can just copy and paste it into the notepad or make a note of it and you can use some of these values in your configuration.

5. The configuration is stored in /etc/nut/ups.conf

So let's edit this file

vim /etc/nut/ups.conf

and add at the end opf file:

[aio]
        driver = nutdrv_qx
        subdriver = fabula
        port = auto
        langid_fix="0x409"
        vendorid = "0001"
        productid = "0000"
        product = "MEC0003"
        vendor = "MEC"
        bus = "003"
        desc = "UPS Green Cell AiO 600VA 360W"
        pollinterval = 5
        override.battery.charge.low = 30
        override.battery.charge.warning = 35
        override.battery.runtime.low = 450
        override.ups.delay.shutdown = 150
        override.ups.delay.start = 60
        override.ups.realpower.nominal = 360
        override.battery.voltage.low = 10.400000
        override.battery.voltage.high = 13.000000
        override.battery.packs = 12
        runtimecal = 600,100,1200,50
        chargetime = 28800
        idleload = 10

You can make a backup of this file or modify it.

I had to test some of these settings and read a NUT documentation that you can find it here: NUT manual

I had to change the driver to nutdrv_qx and modify a little bit the ups.conf to be able to work with the mentioned UPS.

6. Then you have to edit the /etc/nut/upsmon.conf

add a line to monitor a UPS

Edit

/etc/nut/upsd.conf

and modify it to listen on all IP addresses if you want to be able to connect to it from other devices / containers / virtual machines

7. Edit

/etc/nut/nut.conf

And change the mode to netserver

8. Edit

/etc/nut/upsd.users

Add users

[upsmon]
        password  = secret
        upsmon master

If a help is needed with any part, do not hesitate to ask.

Home Assistant

I had to set up Home Assistant as the docker container on a raspberry Pi and add my Green Cell UPS there. I had to do that because I am using AdGuard Home on a Raspberry Pi and I was not able to run it together.

First I had to create a yaml file vim home-assistant.yml

• See home-assistant.yml file

Then run the below commands

Install and configure Docker and Docker Compose

1. The first one installs the docker sudo curl -sSL https://get.docker.com | sh

2. This one creates the user sudo usermod -aG docker ${USER}

3. The next one installs the docker-compose sudo pip3 install docker-compose

4. This one enables the docker to start during the boot process sudo systemctl enable docker

5. And start and check the status

sudo systemctl start docker
sudo systemctl status docker

Home Assistant Docker container

1. Create a docker containter with Home Assistant that runs locally

sudo docker-compose -f home-assistant.yml up -d --remove-orphans

2. Check is the containter running sudo docker ps

3. List all containters sudo docker container ls -a

4. To kill a container, use the below command: sudo docker kill a1c19f3ec04e

5. To restart the container: sudo docker container restart homeassistant

6. Start the container during the boot process sudo docker update --restart unless-stopped $(docker ps -q)

7. The Home Assistant is working locally so, I had to create a ssh tunnel to be able to access it from my laptop.

8. Actually Home Assistant detected UPS automatically. I see the basic information like load, power etc.

BASH SCRIPT

Now it is time to write a bash script that will log into Mikrotik router and perform the shutdown command before the raspberry will shut down. I will use a bash script that I tested on my Mikrotik hap ac2.

Of course sshpass has to be installed with the below command

sudo apt install sshpass

-p 2244 is a nonstandard ssh port

• See the mikrotik.sh file

Then edit crontab

crontab -e

and add the below entry to run every minute:

*/1 * * * * /root/mikrotik.sh

I created a nut user on a mikrotik and additionally tested it with RSA keys without a passphrase what in LAN is let's say secure enough. All you have to do is to save private and public key in openSSH format, but not the newest one, but instead the standard format

• hope I explained it well, just because Puttygen allows you to save the RSA key in new openSSH format. Anyway you have to upload the private key into the Files in Mikrotik router, and then in system - users section import the key for a user. But you can also just use ordinary password with sshpass as I did in the password. If yopu want use RSA, you have to remove this from bash script:

sshpass -f /root/creds

Then you have to add the below line to crontab for root account but it can be also a pi user and it will run every one minute.

*/1 * * * * /root/mikrotik.sh

The default system logger is rsyslog. Add the following to /etc/rsyslog.d/99-nut.conf

• See 99-nut.conf file

Then perform the below commands:

touch /var/log/nut.log
chown root:adm /var/log/nut.log
chmod 640 /var/log/nut.log
systemctl restart rsyslog

All the nut logs will go there.

dmesg presented the below types of alerts

"entered blocking, disabled , forwarding state"

To get rid this from rsyslog I performed the below steps:

sudo vim /etc/udev/rules.d/99-nut-ups.rules

• See 99-nut-ups.rules file

In the file /etc/nut/upssched.conf I defined below actions:

• See upssched.conf file

Early shutdown I have set to 180 seconds.

And the /bin/upssched-cmd file contains the below:

• See upssched-cmd file

My bash script catches the Mikrotik phrase from the log. I had to test it to be sure for 100% it is working as expected.

Finally I have it working and the Raspberry Pi is shutting down as it should.

Sending e-mails

Install th below tools:

sudo apt install postfix msmtp

sudo vim /etc/postfix/main.cf

• See the main.cf file

sudo vim /etc/msmtprc

• See the msmtprc file

sudo vim /etc/aliases

and add at the end

root: your-email address@example.com

Perform the below command

sudo postconf | grep config_directory

Create emailnotify.sh in /root

Then set it as executable

sudo chmod +x emailnotify.sh

Then edit crontab

crontab -e

and add the below entry:

@reboot /root/emailnotify.sh

Now if the UPS will go down you will be notified and also when the raspberry pi will boot up.