How to fix crontab scripts that won't run on Ubuntu 20.04

I've setup what I like to call WOLS (Wake on Lan & Shutdown) servers for a while now; 10 years to be exact.  They are very handy and require little to no system resources; I usually set them up on Hyper-V systems but have also done it on KVM and VMware.  It is very handy if your wanting to schedule systems for auto on and off without buying a commercial server or software.  You also don't have to have it connected to your domain if you don't want it to be.  

I setup a new server on Ubuntu 20.04 for managing the WOL/Shutdown for a remote location and set it up just as I have done in the past; but something was wrong.  It wasn't working.  The system was not turning on or shutting off the systems it was suppose to be.

For the purposes of this post lets say we are going to run all of our scripts out of /scripts/cron

You can use crontab -e or sudo crontab -e to edit cron, I prefer to modify the /etc/crontab file myself.  So when I build my WOLS server and modify the crontab file it usually looks something like this.

After I install the the required tools, WOL, samba tools, etc I white list the, WOL ports, SAMBA and remote desktop/Remote Access ports access though the firewall on both the client and the server. You can also disable the firewalls, though I don't recommend that.

The Startup Script is a shell script called startup.sh and it looks like this

I have found that if I don't put it in the arp cache I tend to have problems if the system has been off for a while.

sudo arp -i -s $IPADDRESS $MACADDRESS #COMMENT

example:

sudo arp -i -s $192.168.0.6 #FF:CC:DD:33:22:00

Then send the WOL Packets

sudo -i -u $SERVERUSER -p $PASSWORD wakeonlan -i $IPADDRESS $MACADDRESS #COMMENT

example:

sudo -i -u serveradm -p password wakeonlan -i 192.168.0.6 #FF:CC:DD:33:22:00

so you use the server usename and password to run the wakeonlan to the ipaddress with the specified mac address. The same is true with the shutdown script but you are using net rpc and you put in the windows client username and password behind the -U in quotes with a % separating the username and password as shown below.

The shutdown script is also a shell script called shutdown.sh and looks like this

sudo -i -u $SERVERUSER -p $PASSWORD net rpc shutdown -I $ipaddress -U "windowsclientusername%password" -t -1 -f 

sudo -i -u serveradm -p password net rpc shutdown -I 192.168.0.6 -U "joedirt%mopboy5" -t 1 -f

With that done, then adding execute permissions to the files and call it a day, as all the scripts worked when I manually executed them. Unfortunately that wasn't the case.  Something changed in Ubuntu 16 that caused files with extensions to not execute.

After troubleshooting and doing some Googling, I found this post with a similar issue to what I was having.  When I did a ls you can see the scripts in the folder.

With my files definitely having execute permission I tried the run-part command 

run-part --test /scripts/cron 

and got the following result

Nothing.  Absolutely nothing listed in the test.  So I did as Pete Fretag suggested and copied my startup.sh and shutdown.sh with out an extension.

Now the startup and shutdown scripts show up in the test.

When I run the scripts using sudo run-part /scripts/cron they also execute where they did not before.