Beginner's guide to an openHABian reboot/shutdown switch

[rpwong (Russ)]

I can’t help you with your specific question, but I’m curious as to what you’re trying to accomplish. It sounds like you’re trying to create a rule to run OH backups. If so, you should look at the Amanda backup tool.

[SOLVED] Back up strategy with Amanda

Using the great readme on Amanda by @mstormi I managed to implement a full SD card backup on my QNAS. Now I’d like to verify this strategy here. So what I have now: I created and NFS share on my QNAP NAS I mounted it to /storage/nas I installed Amanda, selecting the Raw SD card option I ran amdump, the report shows: DUMP SUMMARY: DUMPER STATS TAPER STATS HOSTNAME DISK L ORIG-kB OUT-kB COMP% MMM:SS KB/s MMM:SS …

Truth be told, I haven’t actually installed Amanda. For my purposes, it’s been fine to take an image of my SD card before I make major changes, and simply keep copies of my configuration files (items, rules, etc.) on Google Drive.

[Lanovar]

I keep images of my SD card aswell, but when trying new stuff i backup just for easy restore. After that i can try again.
But sometime i forget to backup when turing off my computer. With this rule i could make a quick backup and copy it later on.

[thisisIO (Michael)]

Thanks for perfect manual!

Please tell, how to stop OH before rebooting or/and to clear cache and reboot.

I mean command like this

sudo service openhab2 stop && sudo rm -rf /var/lib/openhab2/cache/* && sudo rm -rf /var/lib/openhab2/tmp/* && sudo reboot

Is there a way to execute it?

[z9th3 (VinFRa)]

@rpwong, thanks for your straigthforward guide.
I’m on the latest openHabian with Raspbian Buster and having trouble getting this to work.

Using the following command to create/change my sudoers file:
sudo visudo -f /etc/sudoers.d/openhab_userrights

Which in turn looks like this:

#Allow openhab user to execute systemctl command
openhab   ALL=(ALL) NOPASSWD: /sbin/systemctl

When I try to test reboot from the SSH console it is asking me for a password, which according to my understanding should not be happening as NOPASSWD is set in the sudoers file.

[14:18:27] openhabian@openhab:~$ sudo -u openhab /bin/bash
[14:21:36] openhab@openhab:/home/openhabian$ systemctl reboot
User openhabian is logged in on sshd.
Please retry operation after closing inhibitors and logging out other users.
Alternatively, ignore inhibitors and users with 'systemctl reboot -i'.
[14:21:45] openhab@openhab:/home/openhabian$ systemctl reboot -i
==== AUTHENTICATING FOR org.freedesktop.login1.set-wall-message ===
Authentication is required to set a wall message
Authenticating as: root
Password:
[14:22:50] openhab@openhab:/home/openhabian$ sudo systemctl reboot
.
.
.
[sudo] password for openhab:
Sorry, try again.
[sudo] password for openhab:
sudo: 1 incorrect password attempt
[14:23:21] openhab@openhab:/home/openhabian$

The default password for the openhab user (habopen) seems incorrect, but I am weary of changing it to avoid breaking other things.

When triggered over the sitemap the rule is running, but nothing is happening. My assumption is that this is due to authentication issues.

2019-12-15 13:46:43.086 [INFO ] [e.smarthome.model.script.Flag_System] - Rebooting Raspberry Pi
2019-12-15 13:46:43.116 [INFO ] [lipse.smarthome.io.net.exec.ExecUtil] - executed commandLine '[sudo, systemctl, reboot]'

I tried the rule also with a (space) instead of the @@ characters (as the commas from the log made me suspicious), but same result.

I am aware this roadblock is likely due to my limited Linux knowledge, but any help or feedback on this would be very much appreciated.

[rlkoshak (Rich Koshak)]

@z9th3

The default password for the openhab user ( habopen ) seems incorrect, but I am weary of changing it to avoid breaking other things.

The openhab user in the operating system doesn’t have a password. This is by design and is a Linux best practice. The password you are thinking of is for the Karaf Console user which has nothing to do with the operating system.

Beyond that, all I can offer is that it seems the sudoers file you created is not being loaded and applied for some reason. The NOPASSWD means it should not all for a password for that command.

[Udo_Hartmann]

Please try to login via su:

sudo su - openhab -s /bin/bash

tryout another sudo command like

openhab@openhab:~$ sudo ls -l

which should result in something like

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.

[sudo] password for openhab:

then escape and retry (now only the question for password should emerge). escape again.
now tryout systemctl reboot

[rpwong (Russ)]

Did you ever get this figured out? Sorry, I’ve been away from the forums for a long time, and I’m just getting caught up.

[z9th3 (VinFRa)]

Hi @rpwong , sorry for the late reply and thanks for the interest. I basically gave up and started working on other topics in the meanwhile. When I pick it up again I’ll reactivate the thread.

[ffr (F.)]

Restarting Openhab via a rule works fine for me, based on the info in this thread.
Is there a way to also issue caraf commands in a similar way? I like to be able to restart a binding using a rule and a switch item via the Openhab app.

[rpwong (Russ)]

Here’s a discussion about restarting bindings. I’ve been meaning to implement this, but haven’t gotten around to it.

Tutorial: Restart Binding from rule

Hi, sorry, I thought, I have the latest approach in my tutorial above. Actually nowadays I restart (whatever) binding by: executeCommandLine("sudo /usr/bin/ssh -p 8101 -i /home/openhab/karaf_keys/openhab.id_rsa openhab@localhost bundle:restart org.openhab.binding.netatmo", 6000) That works well and actually since the milestone builds I actually don’t need it anymore.

[ewrw (Will)]

Hi @rpwong

I went down a similar path as yourself figuring out how to get a reboot+shutdown to work, though I used buttons on the sitemap (in a sub frame of the site map). I used the visibility option on the sitemap to make a Yes/No dialogue appear/disappear (as necessary) to confirm the action for reboot or shutdown.

Items

String 		Restart_Shutdown 		"Restart/Shutdown"		
Switch		Restart_confirm			"Confirm Restart"			
Switch 		Shutdown_confirm		"Confirm Shutdown"

Sitemap

Switch item=Restart_Shutdown	mappings=["1"="Restart", "2"="Shutdown"]
Switch item=Restart_confirm		mappings=["ON"="Yes","OFF"="No"]	visibility=[Restart_Shutdown=="1"]
Switch item=Shutdown_confirm	mappings=["ON"="Yes","OFF"="No"]	visibility=[Restart_Shutdown=="2"]

Rules

//****************************
//** Restart OpenHab Server **
//****************************
rule "Restart OpenHab Server"
	when
		Item Restart_confirm received command
	then
		switch (receivedCommand) {
			case ON : { logInfo("Restart", *** Restart Server - Sent from UI ***", "\n") Restart_Shutdown.postUpdate(3) Restart_confirm.postUpdate(OFF) executeCommandLine("sudo@@reboot", 10000) }
			case OFF : { Restart_Shutdown.postUpdate("3") }	
		}
	end

//*****************************
//** Shutdown OpenHab Server **
//*****************************
rule "Shutdown OpenHab Server"
	when
		Item Shutdown_confirm received command
	then
	switch (receivedCommand) {
			case ON : { logInfo("Shutdown", *** Shutdown Server - Sent from UI ***", "\n") Restart_Shutdown.postUpdate(3) Shutdown_confirm.postUpdate(OFF) executeCommandLine("sudo@@shutdown", 10000) }
			case OFF : { Restart_Shutdown.postUpdate("3") }	
		}
	end

Thought it worth throwing this into this post.

A small code change is needed for OH3. Please click this LINK for details

[nelson.aponte]

I followed all the instructions on the guide, with the only exception that I’m using HABPanel:

1. Made openhab a super user
2. Created the permissions file with visudo
3. Tested the permissions and they worked
4. Created the Item

String Flag_System "System" <switch>

5. Created a selector with the exact same options
6. Set up the rules

rule "Reboot openHAB"
when
    Item Flag_System received command "Reboot"
then
    logInfo("Flag_System", "Manually rebooting openHAB")
    executeCommandLine("sudo@@reboot", 5000)
end

However, when I change from Active to Reboot or Shutdown on HABPanel, nothing happens. I set the Karaf Console to trace the rule runtime with:

 log:set TRACE org.eclipse.smarthome.model.rule.runtime

I realized that the shutdown/reboot rules are not being triggered when I give the instruction on HABPanel, but other rules are being normally triggered.

My system is Raspbian 9 on a Raspberry Pi 3 with OpenHAB 2.5.2-1

Any suggestions?

[Udo_Hartmann]

Please don’t let user openhab become super user.
Instead use sudo and allow only the commands you need to be used without a password.

I don’t know if this is correct for your version, but in question of exec there is a white list file to permit commands to be executed by exec binding. This option is brand new.

[mstormi (Markus Storm)]

@nelson.aponte

Any suggestions?

Move to openHABian, debug your system if you still have issues that you cannot resolve without restarting OH, then keep your system running 24/7 and forget about that reboot switch. It’s unnecessary and potentially harmful.

[nelson.aponte]

@Udo_Hartmann

Please don’t let user openhab become super user.

I totally agree and also don’t like giving super powers to low-level users. However, when you implement the system for non-technical users, you cannot tell them “log in to the server via SSH and restart it”. You need to provide a user-friendly option, otherwise they will simply go and pull the plug.
OpenHAB should provide such a friendly (and secure) option by default instead of making us look for workarounds.

@mstormi

then keep your system running 24/7 and forget about that reboot switch. It’s unnecessary and potentially harmful.

I personally believe that systems (even highly available ones) should be rebooted periodically for performance reasons, but that’s not part of this discussion and you’re right about pointing out that (doing it this way) is potentially harmful.

@Udo_Hartmann

I don’t know if this is correct for your version, but in question of exec there is a white list file to permit commands tone executed by exec binding.

I’ll take a look at this.

[Udo_Hartmann]

@nelson.aponte

OpenHAB should provide such a friendly (and secure) option by default instead of making us look for workarounds.

Well, yes. But as there is no option for now…

1. login to the GNU/Linux platform where openHAB is active.
2. if not already installed, install sudo
3. grant access for the openhab user by editing the sudoers file. Use visudo for this purpose.
4. setup a line like this: openhab ALL (ALL) NOPASSWD /sbin/reboot
   at the correct context (search for root in the file)
5. install exec and create the correct thing to use the script
6. edit the whitelist to allow openHAB exec to execute sudo /sbin/reboot
7. link an item to the thing and setup a Switch Widget to use the exec channel ‘run’

No need for root. Stay save, but give the user control.
But please be aware that maybe the UI is not reachable anymore, so there might be a better way to restart openHAB by building a script which can be executed remotely (just by a double click on the Desktop Icon maybe with a simple “Are you sure?” )

[mstormi (Markus Storm)]

@nelson.aponte

However, when you implement the system for non-technical users, you cannot tell them “log in to the server via SSH and restart it”. You need to provide a user-friendly option, otherwise they will simply go and pull the plug. OpenHAB should provide such a friendly (and secure) option by default instead of making us look for workarounds.

Definitely no.
Reboots are not needed and do more harm than good. A simple accessible reboot switch just makes the lazy part in everybody surface and quickly get in control instead of taking the painful route to really debug your problem. This is even more true for beginners. That’s not the OH way of doing things.
And that is why most of us (openHABian developers, experienced supporters) with discernment will not support users in getting there.

@nelson.aponte

I personally believe that systems (even highly available ones) should be rebooted periodically for performance reasons

I also disagree with this. If performance degrades over time, that’s just sign of another uncaught bug (mem leak or some such) or bad software design and your time is better invested into looking after that.

[rpwong (Russ)]

@z9th3, did you ever solve this? I’m doing a fresh install on an RPi4 and have run into the same issues with the openhab user requesting a password. @Udo_Hartmann’s suggestion unfortunately isn’t working for me.

I’m suspecting that this guide might need to be rewritten to use the Exec binding, but I’m not sure if that will work either.

[z9th3 (VinFRa)]

@rpwong sorry for the late reply, I have not worked on this issue anymore so I don’t have any good news to report. My need for automatic reboots has decreased because it seems my current system is more stable.

[sihui]

@rpwong

did you ever solve this?

@z9th3

I have not worked on this issue anymore

This was my key to success:

Openhab to access other server via ssh to execute script

You need to generate ssh keys as the openhab user and then copy them across to the target server. I use the following to do this to access a number of other devices to execute scripts locally stored on the remote server. sudo -u openhab ssh-keygen -t rsa then sudo -u openhab ssh-copy-id -i /var/lib/openhab2/.ssh/id_rsa.pub user@hostname You can then test and confirm ssh key access with sudo -u openhab ssh user@hostname and you should have access. Note: I’ve assumed an openhabian install on…