vultr

$ wget https://github.com/JamesClonk/vultr/releases/download/v1.9/vultr_linux_arm.tar.gz
$ tar xvzf vultr_linux_arm.tar.gz -C /usr/local/bin/ --strip 1 vultr_linux_arm/vultr
$ strip /usr/local/bin/vultr

$ systemctl start ddns.timer
$ systemctl enable ddns.timer
$ systemctl list-timers

/etc/systemd/system/ddns.timer

[Unit]
Description=DDNS Timer

[Timer]
OnBootSec=5min
OnUnitActiveSec=1h

[Install]
WantedBy=timers.target

/etc/systemd/system/ddns.service

[Unit]
Description=DDNS Daemon
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/ddns

/usr/local/bin/ddns

#!/bin/sh
#
# update vultr dns record
#
# OPENWRT:
# - opkg install ca-certificates curl
# - wget /etc/ssl/certs/ca-certificates.crt
#

export VULTR_API_KEY=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

VULTR_DNS_DOMAIN=easypi.info
VULTR_DNS_RECORD=home
VULTR_DNS_RECORD_ID=$(vultr dns record list -d $VULTR_DNS_DOMAIN | awk -v x=$VULTR_DNS_RECORD '$3==x{print $1}')
VULTR_DNS_RECORD_DATA=$(curl -s ifconfig.co)

vultr dns record update -d $VULTR_DNS_DOMAIN \
                        -r $VULTR_DNS_RECORD_ID \
                        -D $VULTR_DNS_RECORD_DATA