Fixed the error message. The hostname wasn't quite being set properly…

…, and the name in etc hosts wasn't being updated, but that's all taken care of now and it looks like I've gotten all the instances of the hostname to be consistent

src/modules/wifipi/filesystem/root/usr/bin/update_hostname_and_autohotspot_ssid

@@ -1,12 +1,16 @@
 #!/bin/bash
 
-LAST_4_OF_SERIAL=$(cat /proc/cpuinfo | grep Serial | tail -c 5) # need to grab 5 on account of newline, but the newline won't pose a problem
-# Set the hostname with the hostname command. Convenient.
-hostname "wifipi-$LAST_4_OF_SERIAL"
-# To edit the SSID, we can't just overwrite the file since there are other settings in it
-# We'll use sed, and we'll search for the entire line starting with ssid=WiFiPi, and then
-# we'll replace the entire line. This means that when the card is moved from Pi to Pi, it updates
-# appropriately.
-sed -i s/ssid=WiFiPi.*$/ssid=WiFiPi-$LAST_4_OF_SERIAL/g /etc/hostapd/hostapd.conf
-
-# Reboot Avahi? Or get the service to run before avahi? This is the last part
+LAST_4_OF_SERIAL=$(cat /proc/cpuinfo | grep Serial | tail -c 5) # need to grab 5 on account of newline, but the newline won't get captured into the variable
+# Set the hostname with hostnamectl. Fairly straightforward
+hostnamectl set-hostname "wifipi-$LAST_4_OF_SERIAL"
+# We have to edit the /etc/hosts file manually, and we'll do that using sed so that we 
+# can target the line we want and leave the rest of the file alone. We just need to replace
+# the line starting with 127.0.1.1, and we'll opt to replace the entire line
+sed -i s/127.0.1.1.*/"127.0.1.1 wifipi-$LAST_4_OF_SERIAL"/g /etc/hosts
+# Now, we edit the SSID similarly to how we edited the /etc/hosts file, i.e. using sed to 
+# target the line we want and leave the rest of the file alone. We'll search for the line
+# starting with "ssid=WiFiPi" and as with /etc/hosts/, we'll replace that entire line with
+# what we want. By doing full replace in /etc/hosts and here, we ensure that if the SD card
+# with the OS is ever moved from one Pi to another, the SSID switches appropriately to the serial
+# number of the new Pi
+sed -i s/ssid=WiFiPi.*/ssid=WiFiPi-$LAST_4_OF_SERIAL/g /etc/hostapd/hostapd.conf