From 4e0cced632f1044a697ef9017e05539eda2e54a8 Mon Sep 17 00:00:00 2001
From: changeme <changeme>
Date: Thu, 25 Jun 2020 19:53:02 +0200
Subject: [PATCH 1/2] Only update ip on startup if neccessary

---
 src/ddns_update.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/ddns_update.py b/src/ddns_update.py
index 8c6c370..099ad2c 100755
--- a/src/ddns_update.py
+++ b/src/ddns_update.py
@@ -8,6 +8,7 @@ from os import environ
 from netifaces import interfaces, ifaddresses, AF_INET6
 from ipaddress import ip_address
 from time import sleep
+import socket
 
 logging.basicConfig(level=logging.INFO, format="%(asctime)-15s - %(name)s %(levelname)-8s: %(message)s")
 log = logging.getLogger("ddns updater")
@@ -72,7 +73,9 @@ def ddns_update(host, key, ip):
     help="The ddns authorization key",
 )
 def loop_ddns_update(host, key):
-    last_ip = None
+    last_ip = socket.getaddrinfo(host, None, socket.AF_INET6)[0][4][0]
+    log.debug(f"current registered address: {last_ip}")
+
     while True:
         current_ip = get_global_ipv6()
         if current_ip != last_ip:
@@ -84,4 +87,5 @@ def loop_ddns_update(host, key):
 
 
 if __name__ == "__main__":
+    log.info("starting...")
     loop_ddns_update()

From 53ff70bbf31d23214872730f4bba3e313be0b2d5 Mon Sep 17 00:00:00 2001
From: changeme <changeme>
Date: Thu, 25 Jun 2020 19:55:23 +0200
Subject: [PATCH 2/2] Used click's own environment variable handling

---
 src/ddns_update.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/ddns_update.py b/src/ddns_update.py
index 099ad2c..9de2843 100755
--- a/src/ddns_update.py
+++ b/src/ddns_update.py
@@ -63,13 +63,11 @@ def ddns_update(host, key, ip):
 @click.option(
     "--host",
     required=True,
-    default=lambda: environ.get("DDNS_HOST", None),
     help="The dns name to update",
 )
 @click.option(
     "--key",
     required=True,
-    default=lambda: environ.get("DDNS_KEY", None),
     help="The ddns authorization key",
 )
 def loop_ddns_update(host, key):
@@ -88,4 +86,4 @@ def loop_ddns_update(host, key):
 
 if __name__ == "__main__":
     log.info("starting...")
-    loop_ddns_update()
+    loop_ddns_update(auto_envvar_prefix="DDNS")