OpenWRT

https://openwrt.org/toh/linksys/ea9500_v1
https://firmware-selector.openwrt.org/?version=21.02.3&target=bcm53xx%2Fgeneric&id=linksys_ea9500
https://serialize.wordpress.com/2017/02/01/linksys-ea9500-stuff/#flashing

https://downloads.openwrt.org/releases/21.02.3/targets/bcm53xx/generic/openwrt-21.02.3-bcm53xx-generic-linksys_ea9500-squashfs.trx

opkg update

# ddns
root@OpenWrt:~# opkg list | grep ddns
ddns-scripts - 2.8.2-25
ddns-scripts-services - 2.8.2-25
luci-app-ddns - git-22.193.49501-e0f0502

opkg install curl
mkdir -p /etc/ssl/certs
curl -k https://certs.secureserver.net/repository/sf_bundle-g2.crt >  /etc/ssl/certs/ca-bundle.pem

# NUT
root@OpenWrt:~# opkg list | grep nut
luci-app-nut - git-20.108.38431-8f34e10
nut - 2.7.4-27
nut-common - 2.7.4-27
nut-driver-usbhid-ups - 2.7.4-27
nut-server - 2.7.4-27
nut-web-cgi - 2.7.4-27

root@OpenWrt:~# cat /etc/httpd.conf 
#/cgi-bin/nut:root:$p$root
/cgi-bin/nut

root@OpenWrt:~# cat /etc/config/nut_server 
#config driver_global 'driver_global'
#	option user nut

config driver 'apc1000'
	option driver usbhid-ups
	option port auto
	#option enable_usb_serial 0

config user
	#option username ups
	#option password ups
#	option actions optional-action
#	list instcmd optional-instant-command
	option upsmon master

#config listen_address
#	option address ::1
$	option port 3493

#config upsd 'upsd'
#	option maxage 15
#	option statepath /var/run/nut
#	option maxconn 1024
#	option runas nut
# NB: certificates only apply to SSL-enabled version
#       option certfile /usr/local/etc/upsd.pem

root@OpenWrt:~# cat /etc/config/nut_cgi 
config host
	option upsname apc1000 
#	option hostname localhost
#	option port # optional port number
	option displayname "APC 1000"

config upsset
	option enable 0