Adapter refactor

Allows using different ways to retrieve hosts IP address

transip_client/adapters.py

@@ -0,0 +1,86 @@
+import logging
+import subprocess
+
+import requests
+
+
+logger = logging.getLogger(__name__)
+
+
+class Adapter:
+    def get_ip(self) -> str:
+        raise NotImplementedError
+
+
+class HTTPAdapter(Adapter):
+    service: str
+
+    def handle_response(self, response: requests.Response) -> str:
+        raise NotImplementedError
+
+    def get_params(self) -> dict:
+        raise NotImplementedError
+
+    def get_ip(self) -> str:
+        try:
+            response = requests.get(self.service, params=self.get_params(), timeout=5)
+            response.raise_for_status()
+        except requests.RequestException as e:
+            raise OSError(f"Unable to retrieve current IP from {self.service}") from e
+
+        ip = self.handle_response(response)
+
+        if not ip:
+            raise OSError(f"Unable to determine IP from response from {self.service}")
+
+        return ip
+
+
+class IpifyAdapter(HTTPAdapter):
+    service: str = "https://api.ipify.org"
+
+    def get_params(self) -> dict:
+        return {"format": "text"}
+
+    def handle_response(self, response: requests.Response) -> str:
+        return response.text
+
+
+class DNSAdapter(Adapter):
+    resolvers: list[str]
+    dns: str
+
+    def try_resolver(self, resolver: str) -> str:
+        output = subprocess.check_output(
+            ["dig", "+short", self.dns, resolver], stderr=subprocess.STDOUT, text=True
+        )
+
+        return output.strip()
+
+    def get_ip(self) -> str:
+        for resolver in self.resolvers:
+            try:
+                ip = self.try_resolver(resolver)
+            except subprocess.CalledProcessError as e:
+                if e.returncode == 9:
+                    continue
+
+                raise OSError("Unable to retrieve current IP") from e
+
+            if not ip:
+                logger.warning(f"No IP returned from {resolver}")
+                continue
+
+            return ip
+
+        raise OSError("Exhausted all known IP resolvers, unable to retrieve IP")
+
+
+class OpenDNSAdapter(DNSAdapter):
+    dns = "myip.opendns.com"
+    resolvers = [
+        "@resolver1.opendns.com",
+        "@resolver2.opendns.com",
+        "@resolver3.opendns.com",
+        "@resolver4.opendns.com",
+    ]