Dynamically Create SSID for Linux AP Hotspot

README

make_ssid.sh goes in /etc/hostapd/
The service file goes in /etc/systemd/system/

hostapd_set_ssid.service

[Unit]
Description=Setup ssid to use for hostapd
Before=hostapd.service

[Service]
Type=oneshot
ExecStart=/bin/bash /etc/hostapd/make_ssid.sh
StandardOutput=journal+console

[Install]
WantedBy=multi-user.target

make_ssid.sh

#!/bin/bash

set -e

egrep -v "^ssid" /etc/hostapd/hostapd.conf > /tmp/hostapd.new
grep Serial /proc/cpuinfo  | awk  '{ print "ssid=example_ssid_" $3 }' >> /tmp/hostapd.new
mv /tmp/hostapd.new /etc/hostapd/hostapd.conf