From 4f1547a61bc90db8723243f2aa4ed51962255f2b Mon Sep 17 00:00:00 2001
From: Julian Lobbes <julian.lobbes@protonmail.com>
Date: Sat, 3 Sep 2022 00:36:30 +0200
Subject: [PATCH] feat: implement update script

---
 dnsupdate.py | 90 +++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 86 insertions(+), 4 deletions(-)
 mode change 100644 => 100755 dnsupdate.py

diff --git a/dnsupdate.py b/dnsupdate.py
old mode 100644
new mode 100755
index 7227cd7..b5b76e9
--- a/dnsupdate.py
+++ b/dnsupdate.py
@@ -11,16 +11,98 @@ except ImportError:
     from yaml import Loader
 
 
+_API_ENDPOINT_URL = "https://api.hosting.ionos.com/dns/v1/dyndns"
+
+
+class InvalidConfigurationError(RuntimeError):
+    """Raised when the configuration file's contents are invalid."""
+
+
 def main():
     path_to_config_file = Path("config.yml").resolve()
 
-    # TODO Check if config file exists
+    # Check if config file exists
+    if not path_to_config_file.is_file():
+        raise FileNotFoundError(
+            f"No such file: '{path_to_config_file}'."
+        )
 
-    # TODO parse config file
+    # Load config file
+    with open(path_to_config_file, 'r') as config_file:
+        config = load(config_file, Loader=Loader)
 
-    # TODO retrieve DNS update URL
+    # Validate config file
+    for top_level_key in ["apikey", "domains"]:
+        if not top_level_key in config:
+            raise InvalidConfigurationError(
+                f"Failed to locate key '{top_level_key}' in config."
+            )
+    # Validate 'apikey' values
+    for key in ["prefix", "secret"]:
+        if not key in config["apikey"]:
+            raise InvalidConfigurationError(
+                f"Expected key 'apikey.{key}' in config:"
+            )
+        if not isinstance(config["apikey"][key], str):
+            raise InvalidConfigurationError(
+                f"Expected type string as the value for 'apikey.{key}'."
+            )
+    # Validate 'domains' values
+    if not isinstance(config["domains"], list):
+        raise InvalidConfigurationError(
+            "Expected type list as the value for 'domains'."
+        )
+    for value in config["domains"]:
+        if not isinstance(value, str):
+            raise InvalidConfigurationError(
+                f"Expected only strings in the 'domains' list."
+            )
+    # Validate 'description' value
+    if "description" in config:
+        if not isinstance(config["description"], str):
+            raise InvalidConfigurationError(
+                "Expected type string as value for 'description'."
+            )
 
-    # TODO send update
+    # Parse config
+    apikey_prefix = config["apikey"]["prefix"]
+    apikey_secret = config["apikey"]["secret"]
+    apikey = f"{apikey_prefix}.{apikey_secret}"
+    domains = config["domains"]
+    description = config["description"] if "description" in config else "Dynamic DNS update."
+
+    # 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,
+        }
+    )
+
+    if not response.status_code == 200:
+        try:
+            error_message = f"{response.status_code}: {response.json()}"
+        except requests.exceptions.JSONDecodeError:
+            error_message = f"{response.status_code}"
+        raise RuntimeError(
+            f"API request failed and returned: {error_message}"
+        )
+
+    update_url = response.json()["updateUrl"]
+    print(update_url) # DEBUG
+
+    # Send a dynamic DNS update using the retrieved update URL
+    response = requests.get(update_url)
+    if not response.status_code == 200:
+        try:
+            error_message = f"{response.status_code}: {response.json()}"
+        except requests.exceptions.JSONDecodeError:
+            error_message = f"{response.status_code}"
+        raise RuntimeError(
+            f"DNS update request failed and returned: {error_message}"
+        )
 
 
 if __name__ == "__main__":