fix: missing Content-Type-header in API request

dnsupdate.py

@@ -3,7 +3,7 @@
 """A script which sends a Dynamic DNS update to the Ionos API."""
 
 from pathlib import Path
-import requests
+import json, requests
 from yaml import load
 try:
     from yaml import CLoader as Loader
@@ -70,15 +70,22 @@ def main():
     apikey = f"{apikey_prefix}.{apikey_secret}"
     domains = config["domains"]
     description = config["description"] if "description" in config else "Dynamic DNS update."
+    payload = json.dumps(
+        {
+            "domains": domains,
+            "description": description,
+        },
+        indent=2,
+    )
 
     # Make an API call to retrieve the DNS update URL
     response = requests.post(
         _API_ENDPOINT_URL,
-        headers={"X-API-Key": apikey},
-        data={
-            "domains": domains,
-            "description": description,
-        }
+        headers={
+            "Content-Type": "application/json",
+            "X-API-Key": apikey,
+        },
+        data=payload
     )
 
     if not response.status_code == 200:
@@ -90,8 +97,12 @@ def main():
             f"API request failed and returned: {error_message}"
         )
 
+    try:
         update_url = response.json()["updateUrl"]
-    print(update_url) # DEBUG
+    except requests.exceptions.JSONDecodeError as e:
+        raise RuntimeError(
+            "Failed to parse update URL from API response."
+        ) from e
 
     # Send a dynamic DNS update using the retrieved update URL
     response = requests.get(update_url)