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Delayed Shutdown

Marc

April 02, 2020 02:49

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Hello,

I am trying to shutdown a Pi with Amp+ from an SSH session with HomeKit.

The issue I am having is that I am not able to log off from the SSH session in time before the Pi shuts down.  This throws an error in HomeKit.

Normally, the command below works, but HiFiBerryOS doesn't have logind running:

shutdown -h +1
exit

I've tried lots of workarounds, various forms of:

(sleep 5; shutdown)& exit

The shell doesn't spawn a new process no matter what I try, and runs the commands in order, shutting down the Pi before I can exit the SSH session.

Any thoughts on how to have a delayed shutdown so we can properly exit the SSH session?

Loving this project, great work!

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15 comments

• 0
  
  HiFiBerry team April 02, 2020 12:44

  I can't think about an easy way to do this. I would rather check on the system that starts the SSH connection to ignore the broken connection there.

• 0
  
  Marc April 02, 2020 12:56

  I am limited on the client SSH side of the equation unfortunately.

  What's the best way to power off the device programmatically?

  Websocket call to the web server?  Any other ideas?

  Thanks for your time.

• 0
  
  Tuomas April 02, 2020 13:02

  Hi Marc,

  there's a shutdown option available in the web interface, under General -> Power. You can use this independently from SSH and it executes the shutdown command behind the scenes.

  Does this work for you or do you need other options?

  Best,

  Tuomas from Bang & Olufsen

• 0
  
  Marc April 02, 2020 13:06

  Hi Tuomas,

  I am looking for a programmatic way to shutdown.  Trying to save power when the devices aren't in use.

  Thanks for the reply!

• 0
  
  Tuomas April 02, 2020 13:12

  Yeah, I realised this afterwards.

  It is possible to connect to the websocket that's used for communication between the web interface and the server and then submit a shutdown message.

  The socket runs on port 80 and accepts connections with "beocreate" protocol. Once connected, sending the following JSON over the socket should trigger shutdown:

  {"target": "product-information", "header": "shutdownProduct"}

  Let me know if this works for you.

  Edited by Tuomas April 02, 2020 13:13
• 0
  
  Marc April 02, 2020 13:25

  Yes and no. I tested the websocket idea yesterday from my dev machine and it works. 

  However, my client side run time for this project is pretty limited and can't use websockets, so I had to give up on that idea.

  I really don't know what to do outside of programmatically pulling the power from my power supply, which isn't great for the hardware.

  I don't want to branch because the auto updates are a big reason why I've chosen on your OS.

• 0
  
  Paul April 02, 2020 13:58

  Try

  { sleep 10; reboot; }& exit

  in bash. Works for me on a debian based machine via ssh. Mind the parantheses being braces.

• 0
  
  Tuomas April 02, 2020 14:02

  Hi Paul,

  thanks for pitching in, I just tested this and it appears to work.

  Marc, if you still need help with accomplishing what you want, just let us know and we'll try our best to accommodate you.

   

  Best,

  Tuomas from Bang & Olufsen

• 0
  
  Marc April 02, 2020 21:29

  Hi Guys,

  Yes, I've gotten the 

  { sleep 10; reboot; }& exit

  to work in bash as well, but this doesn't work in the iOS home automation or shortcuts SSH client for some reason.  It seems to only execute in synchronous fashion, regardless of any syntax tricks that I can find.

  As I've said:

  shutdown -h +1
  exit

  Works, but requires the logind service to be running on the device which seems extraneous, the thing I love about your project is that it's so efficient, nothing extra running.

  Seems like the issue here is with the shortcomings of the SSH client that iOS provides to home automation tasks.

  Maybe a small api on HifiberryOS would be slick and lightweight, just run it out of the same Express instance.  Might be handy for other home automators, especially as the OS gets more features. 

  I realize that's some work on your end and maybe unlikely...I'll try and find a solution on the client side of things here, and report back.

  Thanks gentleman!

• 0
  
  Tuomas April 02, 2020 21:49

  It just so happens that I'm working on a feature, which allows creating custom interactions right in the UI by connecting triggers with actions. The inspiration for this is from an earlier project in which we wanted to use different Arduino contraptions to control music. I can easily add a HTTP API call as one of the triggers and shutdown/reboot as one of the actions that one can pair up.

  In this example, I'm listening for a certain message through a serial port to trigger turning volume up:

  

• 0
  
  Marc April 02, 2020 22:31

  Love it, an HTTP API call would do the trick!

• 0
  
  HiFiBerry team April 06, 2020 07:03

  I have just packaged an experimental release with the first version of the "Interact" module. Note that this is very experimental, I can't guarantee that it will work.
  
  You can upgrade to this release using the command
  
  /opt/hifiberry/bin/update --experimental

   

   

• 0
  
  Tuomas April 06, 2020 10:23

  Once you have upgraded, you can set this up with the following steps:

  1. Go to the new Interact screen that's in the navigation bar/menu.
  2. Select New Interaction.
  3. Choose a trigger and select Web Request Received.
  4. Set the end of the trigger address to what you want, and check the full address for the request.
  5. Add an action and choose Power, then select Shut Down Raspberry Pi.
  6. Save and name your interaction.

  Now, sending a POST request to the address you specified should shut down the Raspberry Pi.

  Let us know if this does the trick for you.

  Best,

  Tuomas from Bang & Olufsen

  Edited by Tuomas April 06, 2020 10:24
• 0
  
  Marc April 06, 2020 14:15

  Works like a charm, really nice to have this level of control.  Nice work gentleman!

• 0
  
  Tuomas April 06, 2020 14:27

  Cheers Marc, awesome to hear that.

   

  Best,

  Tuomas