systemd scripts

dns-updater.sh

#!/bin/sh

JSON_LOC="/path/to/file.json"
DNS_ZONE="myzone"
DNS_RECORD="sub.example.com"
TTL=300
CURRENT_RECORD_IP=$(dig +short $DNS_RECORD)
CURRENT_IP=$(curl ifconfig.io/ip)

if [ "$CURRENT_IP" = "$CURRENT_RECORD_IP" ]
then
        echo "no changes"
        exit 0
fi

#authenticate
gcloud auth activate-service-account --key-file=$JSON_LOC

gcloud dns record-sets transaction start   --zone=$DNS_ZONE
gcloud dns record-sets transaction remove  --zone=$DNS_ZONE --name=$DNS_RECORD --type=A "$CURRENT_RECORD_IP" --ttl=$TTL
gcloud dns record-sets transaction add     --zone=$DNS_ZONE --name=$DNS_RECORD --type=A "$CURRENT_IP"        --ttl=$TTL
gcloud dns record-sets transaction execute --zone=$DNS_ZONE

docker-compose.yml

version: "3"

# More info at https://github.com/pi-hole/docker-pi-hole/ and https://docs.pi-hole.net/
services:
  pihole:
    container_name: pihole
    image: pihole/pihole:latest
    ports:
      - "53:53/tcp"
      - "53:53/udp"
      - "67:67/udp"
      - "80:80/tcp"
      - "443:443/tcp"
    restart: always
    environment:
      TZ: 'America/New York'
      WEBPASSWORD: '<password>'
    # HOSTNAME: "pi-hole"
    # Volumes store your data between container upgrades
    volumes:
      - './etc-pihole/:/etc/pihole/'
      - './etc-dnsmasq.d/:/etc/dnsmasq.d/'
    # Recommended but not required (DHCP needs NET_ADMIN)
    #   https://github.com/pi-hole/docker-pi-hole#note-on-capabilities
    cap_add:
      - NET_ADMIN
    restart: unless-stopped

docker_update

#!/bin/sh

docker-compose down
docker-compose pull
docker-compose up --detach

example-dns_update.service

#Path = /etc/systemd/system/dns_update.service

[Unit]
Description=Script to update Google Cloud DNS records for "my.example.com"

[Service]
Type=simple
ExecStart=/usr/bin/env bash /etc/google-cloud-sdk/scripts/dns-updater

[Install]
WantedBy=multi-user.target

example-dns_update.timer

#Path = /etc/systemd/system/conlon-dns_update.timer

[Unit]
Description=Run "conlon-dns_update.service" to update the A record every half hour/

[Timer]
OnCalendar=*-*-* *:00/30:00
Unit=example-dns_update.service

[Install]
WantedBy=multi-user.target

pihole_update.service

#Path = /etc/systemd/system/pihole_update.service

[Unit]
Description=Script to update pihole docker image.

[Service]
Type=simple
WorkingDirectory=/home/pi/docker/pihole
ExecStart=/usr/bin/env bash /home/pi/docker/pihole/docker_update

[Install]
WantedBy=multi-user.target

pihole_update.timer

#Path = /etc/systemd/system/pihole_update.timer

[Unit]
Description=Run "pihole_update.service" to update pihole image once a day

[Timer]
OnCalendar=daily
Unit=pihole_update.service

[Install]
WantedBy=multi-user.target