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Apple Hardware Linux Misc Networking Software Windows www

Remote desktop and Wake-on-LAN

Shan uses her iPad a lot, but a lot of the more serious (interior design) work needs to happen on AutoCAD or Photoshop. That is just not going to work on an iPad.

When we’re travelling (read: holiday) she’s carrying an old Lenovo ThinkPad 13 (great device!) just “in case” she needs to open AutoCAD and edit something minor or read the drawings/dimensions. But honestly, most of the time that device is turned off and dead weight.

But all the above is just an excuse to “I was bored, and I wanted to test something”: can I use an old Raspberry Pi (zero W) to remotely wake her Intel NUC, and then use Tailscale to use RD on her iPad? Well, yes I can.

I completed this using:

  • Tailscale to remote desktop from anywhere to home
  • Cloudflare Tunnels, Access and DNS to have a web interface to wake the desktop
  • A Linux device that’s always on and in the same LAN, and that’ll run a PHP script.

Prep work: enable WOL

First off: enable Wake-on-LAN (WOL) in the BIOS and in your Windows settings. This article explains it for Intel NUCs, but would be similar enough for most devices. The Device Manager pane looked different on our i5 NUC, but was close enough.

On Mac, you just need to enable it in the Energy preference pane, for Linux I have no clue. 🤷‍♂️

Second step: have a working Raspberry Pi (or any Linux device) in the same LAN. This device needs to be turned on 24/7, so use something that uses very little power.

I do have a more powerful RPi4 I wish I could've reused (running Docker and some other "serious" stuff; however it's currently in a different VLAN, and it's quite crucial the Linux device is in the same LAN as the device(s) you want to wake up), so I went with an old Raspberry Pi Zero W that was collecting dust (it used to run pwnagotchi).

On the Linux device, install etherwake. The command to run is quite simply etherwake aa:bb:cc:11:22:33 (= the ethernet MAC address of your device).

If this doesn’t wake your desktop, something is wrong and there’s no point continuing. Go and troubleshoot.

Install Tailscale and RD

On the (Windows) desktop and your iPad, install Tailscale. Login, and make sure it works by pinging from one to the other.

Then set up Remote Desktop on both (Windows, iPad). You should test and make sure you can properly connect using the LAN IP address and then the Tailscale IP address.

Fun fact: I create a DNS record for all my devices using Cloudflare DNS with the syntax of device-name.ts.yeri.be, so I don't need to ever remember IPs, and can easily ssh or ping devices without having to look up IPs. 
Cloudflare DNS screenshot, filtered on “ts”. I add both A and AAAA records (not shown in the screenshot)
Fun fact side track: I actually have a dynamic script that runs (on Linux) and creates hostname.ts.yeri.be for the Tailscale IP, hostname.wg.yeri.be based on the Wireguard IP, hostname.lan.yeri.be based on the LAN IP. This dyndns script runs every so often and updates IPs if needed. All this is running using Cloudflare DNS and their API. Super convenient.

Nginx, php and etherwake

I'm a 80s kid, so I'll use dirty PHP to run this script. I'm sure I'll go straight to hell for this, but yolo.

Install nginx and PHP (no need for MySQL and other stuff).

etherwake requires root to run (because it needs root access to create a weird magic ethernet packet). Create a file in /etc/sudoers.d/etherwake and add this line:

www-data ALL=(ALL) NOPASSWD: /usr/sbin/etherwake

This will allow www-data (nginx/php) to run /usr/sbin/etherwake using sudo, without password.

In /var/www/html/ create an index.php file with:

<html>
<head><title>Wake on Lan</title></head>
<body>
<p>Wake up <a href="mycooldesktop.php">My Cool Desktop</a>
</body>
</html>

And a mycooldesktop.php (or whatever) file with:

<?php
$output = shell_exec('sudo /usr/sbin/etherwake aa:bb:cc:11:22:33 2>&1');
echo "<pre>$output</pre>";
?>
<p><a href="..">Back</a></p>
It ain't pretty -- but it gets the job done. 

And be sure to edit the MAC address to match your desktop’s ethernet MAC address.

Cloudflare tunnels

Install Cloudflare Tunnel (via Zero Trust dashboard).

When creating a new tunnel, the dashboard will give you all needed commands to install the tunnel on your RPi — but be sure to select the right OS/architecture (arm64? arm? armhf?).

Easy.

And then point the tunnel to http://localhost. No need to mess around with SSL certs.

Lastly, set up Cloudflare Access (via the same Zero Trust dashboard): create a new application, and make sure only approved users can sign in (i.e.: using a pin code emailed to only approved emails).

I only allow access to my own emails, and my family, by using groups.

You can try it yourself via wol.superuser.one. You won’t get in. 🙂

Optionally, but recommended: lock down Nginx to only allow connections from localhost (127.0.0.0/8 and ::1) if using Cloudflare Tunnels, or Cloudflare IPs if using port forwarding with Cloudflare Access in front. 
Love my design skills… But it gets the job done: click that link, and it’ll execute etherwake.

To recap

  • We used Tailscale to create a VPN network between the desktop and the iPad. The big benefit is that Tailscale works effortlessly across NAT networks without having to open ports,
  • We used Cloudflare DNS so we don’t need to remember hostnames :),
  • We used Cloudflare Tunnels to make sure the RPi web interface is accessible across NAT (without port forwarding) and from anywhere,
  • We used Cloudflare Acces and locked down access to the right people using ACLs,
  • We used etherwake running on a RPi to wake up devices that are hibernating or turned off.

And that’s it really.

PS: technically WoL works with WiFi, but when I enabled WoL on the WiFi adapter, the NUC refused to hibernate/sleep for more than a minute, and kept waking itself up. So, there seems to be some kind of trigger in my network that keeps waking it up. Also, not sure if WoL via WiFi would work if the device is turned off (as opposed to sleep or hibernate). I just ended up using ethernet. 

PPS: both Cloudflare Tunnels and Tailscale use Wireguard tech in the background, so that's really cool. 
Categories
Apple

Chicken Rice / Poached

And of course the actual ad (how iPhone is super mega amazing) 🤷🏼‍♂️ but nice to see how they did it. And neat to see how tech evolved since my first iPhone 3G. What they fail to mention is the insane time it takes to film all that, and the post production editing… 😉

Categories
Apple

Airtags, DHL and North Korea

Fun project, and crappy customer service from DHL.

Categories
Apple Google Hardware

Custom CPUs

Google developing own CPUs for Chromebook laptops“.

Interesting to see that many years after Apple started creating their CPUs for the iPhone (and now laptops/desktops), so many companies are following. Google is not new to building their chips (TPU, Titan (used in security keys and as encryption module for servers/Pixel phones), and likely more), but quite new to more generalised computing CPU for phones and laptops.

And it makes sense — a lot of the generic CPUs were too generalist and not that great at their job (and are plagued with bugs). It came with heavy power usage. Having a ML/AI chip, a GPU chip, a generalist CPU chip (or two, one focussing on high performance, and one on efficiency, like the M1), one for security/encryption (Titan/T2), etc.

Curious to see how much of a head start Apple really has, and very eager to finally see some real innovation in the CPU space (sorry AMD with Ryzen: too little, too late).

Let’s see if Intel and AMD will be able to adapt and reinvent themselves and what it means for ARM (and the ARM IP issue in China), and if other architectures like MIPS are making a chance.

Categories
Apple Hardware

AirPod Max stuck at 74% battery

I’ve noticed my AirPod Max being stuck at ~74% battery and not wanting to charge any further. It’s running the latest firmware and I usually charge them on a (legit) usb-A-to-lightning cable connected to my monitor. Even keeping them connected charging overnight would somehow max out at 74%.

There are a few Reddit posts with other people facing the same issue with AirPod Pros (case not wanting to charge further than 74%) but no concrete answer or solution is posted.

For me, what helped, was to use a wall charger (doesn’t have to be Apple); it’s still using a similar usb-A-to-lightning cable. Letting it charge for a while managed to get it to 100%.

Why 74% and not… 75%? ¯\_(ツ)_/¯

Edit: as some people pointed out, this may actually be Apple’s Optimized Battery Charging. I am not seeing any notification though.