Added the DNS updater for OVH DNS

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        repository: [rsync-server, sshd, webhook, gandi, http-tunnel, piwigo-souvenirs, restic-auto, restic-rest, shairport-sync, telegraf]
+        repository: [dnsupdater, rsync-server, sshd, webhook, gandi, http-tunnel, piwigo-souvenirs, restic-auto, restic-rest, shairport-sync, telegraf]
 
     steps:
       - name: Checkout

dnsupdater/Dockerfile

@@ -0,0 +1,8 @@
+FROM alpine:latest
+
+ADD dnsupdater.sh /usr/bin/dnsupdater.sh
+
+RUN apk add --no-cache bash curl jq bind-tools \
+	&& chmod +x /usr/bin/dnsupdater.sh
+
+CMD /usr/bin/dnsupdater.sh

dnsupdater/dnsupdater.sh

@@ -0,0 +1,58 @@
+#!/bin/bash
+
+while true ; do
+  # Get my current IP
+  my_ip=$(curl -s https://api.ipify.org)
+
+  # Get my currently registered IP
+  current_ip=
+  if [[ "$GANDI_API_KEY" != "" ]] ; then
+    current_ip=$(curl -s -H"X-Api-Key: $GANDI_API_KEY" https://dns.api.gandi.net/api/v5/domains/$DNS_DOMAIN/records | jq -r '.[] | select(.rrset_name == "'$DNS_HOST'") | select(.rrset_type == "A") | .rrset_values[0]')
+  elif [[ "$OVH_USERNAME" != "" ]] ; then
+    current_ip=$(dig +short @dns13.ovh.net $DNS_HOST.$DNS_DOMAIN)
+  fi
+
+  # Check if both IP addresses are correct
+  if [[ "$my_ip" =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ && "$current_ip" =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]] ; then
+    # If they do not match, change it (and keep the TTL and TYPE)
+    if [[ "$my_ip" != "$current_ip" ]]; then
+      result=1
+      echo "Updating $DNS_HOST.$DNS_DOMAIN record with IP $my_ip"
+      if [[ "$GANDI_API_KEY" != "" ]] ; then
+        current_record=$(curl -s -H"X-Api-Key: $GANDI_API_KEY" https://dns.api.gandi.net/api/v5/domains/$DNS_DOMAIN/records | jq -c '.[] | select(.rrset_name == "'$DNS_HOST'") | select(.rrset_type == "A")')
+        current_ttl=$(echo $current_record | jq -r '.rrset_ttl')
+        curl -s -X PUT -H "Content-Type: application/json" -H "X-Api-Key: $GANDI_API_KEY" -d '{"rrset_ttl": '$current_ttl', "rrset_values":["'$my_ip'"]}' https://dns.api.gandi.net/api/v5/domains/$DNS_DOMAIN/records/$DNS_HOST/A
+	result=$?
+      elif [[ "$OVH_USERNAME" != "" ]] ; then
+        curl --user "$OVH_USERNAME:$OVH_PASSWORD" "http://www.ovh.com/nic/update?system=dyndns&hostname=$DNS_HOST.$DNS_DOMAIN&myip=$my_ip"
+	result=$?
+      fi
+
+      # If the update was OK
+      if [[ $result == 0 ]] ; then
+        # Send a notification to Slack
+        if [[ "$SLACK_URL" != "" ]] ; then
+          curl -o /dev/null -s -m 10 --retry 5 -X POST -d "payload={\"username\": \"gandi\", \"icon_emoji\": \":dart:\", \"text\": \"New IP $my_ip for host $DNS_HOST.$DNS_DOMAIN\"}" $SLACK_URL
+        fi
+
+        # Send a notification to Gotify
+        if [[ "$GOTIFY_URL" != "" ]] ; then
+          curl -o /dev/null -s -m 10 --retry 5 -X POST -H "accept: application/json" -H "Content-Type: application/json" -d "{\"priority\": 5, \"title\": \"New IP for host $DNS_HOST.$DNS_DOMAIN\", \"message\": \"New IP $my_ip for host $DNS_HOST.$DNS_DOMAIN, the old IP was $current_ip\"}" $GOTIFY_URL
+        fi
+
+        # Send a notification to Healthchecks
+        if [[ "$HEALTHCHECKS_URL" != "" ]] ; then
+          curl -o /dev/null -s -m 10 --retry 5 $HEALTHCHECKS_URL
+        fi
+      fi
+    else
+      # Send a notification to Healthchecks
+      if [[ "$HEALTHCHECKS_URL" != "" ]] ; then
+        curl -o /dev/null -s -m 10 --retry 5 $HEALTHCHECKS_URL
+      fi
+    fi
+  fi
+
+  # Wait 5 minutes
+  sleep 300
+done