chore: working code path

Author: jackwotherspoon

google/cloud/sql/connector/__init__.py

@@ -18,12 +18,16 @@
 from google.cloud.sql.connector.connector import create_async_connector
 from google.cloud.sql.connector.enums import IPTypes
 from google.cloud.sql.connector.enums import RefreshStrategy
+from google.cloud.sql.connector.resolver import DefaultResolver
+from google.cloud.sql.connector.resolver import DnsResolver
 from google.cloud.sql.connector.version import __version__
 
 __all__ = [
     "__version__",
     "create_async_connector",
     "Connector",
+    "DefaultResolver",
+    "DnsResolver",
     "IPTypes",
     "RefreshStrategy",
 ]

google/cloud/sql/connector/connection_info.py

@@ -57,6 +57,9 @@ async def create_ssl_context(self, enable_iam_auth: bool = False) -> ssl.SSLCont
             return self.context
         context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
 
+        # update ssl.PROTOCOL_TLS_CLIENT default
+        context.check_hostname = False
+
         # TODO: remove if/else when Python 3.10 is min version. PEP 644 has been
         # implemented. The ssl module requires OpenSSL 1.1.1 or newer.
         # verify OpenSSL version supports TLSv1.3

google/cloud/sql/connector/connector.py

@@ -37,6 +37,8 @@
 import google.cloud.sql.connector.pg8000 as pg8000
 import google.cloud.sql.connector.pymysql as pymysql
 import google.cloud.sql.connector.pytds as pytds
+from google.cloud.sql.connector.resolver import DefaultResolver
+from google.cloud.sql.connector.resolver import DnsResolver
 from google.cloud.sql.connector.utils import format_database_user
 from google.cloud.sql.connector.utils import generate_keys
 
@@ -63,6 +65,7 @@ def __init__(
         user_agent: Optional[str] = None,
         universe_domain: Optional[str] = None,
         refresh_strategy: str | RefreshStrategy = RefreshStrategy.BACKGROUND,
+        resolver: DefaultResolver | DnsResolver = DefaultResolver,
     ) -> None:
         """Initializes a Connector instance.
 
@@ -104,6 +107,12 @@ def __init__(
                 of the following: RefreshStrategy.LAZY ("LAZY") or
                 RefreshStrategy.BACKGROUND ("BACKGROUND").
                 Default: RefreshStrategy.BACKGROUND
+            resolver (DefaultResolver | DnsResolver): The class name of the
+                resolver to use for resolving the Cloud SQL instance connection
+                name. To resolve a DNS record to an instance connection name, use
+                DnsResolver.
+                Default: DefaultResolver
+
         """
         # if refresh_strategy is str, convert to RefreshStrategy enum
         if isinstance(refresh_strategy, str):
@@ -157,6 +166,7 @@ def __init__(
         self._enable_iam_auth = enable_iam_auth
         self._quota_project = quota_project
         self._user_agent = user_agent
+        self._resolver = resolver()
         # if ip_type is str, convert to IPTypes enum
         if isinstance(ip_type, str):
             ip_type = IPTypes._from_str(ip_type)
@@ -269,13 +279,14 @@ async def connect_async(
         if (instance_connection_string, enable_iam_auth) in self._cache:
             cache = self._cache[(instance_connection_string, enable_iam_auth)]
         else:
+            conn_name = await self._resolver.resolve(instance_connection_string)
             if self._refresh_strategy == RefreshStrategy.LAZY:
                 logger.debug(
                     f"['{instance_connection_string}']: Refresh strategy is set"
                     " to lazy refresh"
                 )
                 cache = LazyRefreshCache(
-                    instance_connection_string,
+                    conn_name,
                     self._client,
                     self._keys,
                     enable_iam_auth,
@@ -286,7 +297,7 @@ async def connect_async(
                     " to backgound refresh"
                 )
                 cache = RefreshAheadCache(
-                    instance_connection_string,
+                    conn_name,
                     self._client,
                     self._keys,
                     enable_iam_auth,

google/cloud/sql/connector/exceptions.py

@@ -70,3 +70,10 @@ class IncompatibleDriverError(Exception):
     Exception to be raised when the database driver given is for the wrong
     database engine. (i.e. asyncpg for a MySQL database)
     """
+
+
+class DnsResolutionError(Exception):
+    """
+    Exception to be raised when an instance connection name can not be resolved
+    from a DNS record.
+    """

google/cloud/sql/connector/instance.py

@@ -26,7 +26,7 @@
 
 from google.cloud.sql.connector.client import CloudSQLClient
 from google.cloud.sql.connector.connection_info import ConnectionInfo
-from google.cloud.sql.connector.connection_name import _parse_instance_connection_name
+from google.cloud.sql.connector.connection_name import ConnectionName
 from google.cloud.sql.connector.exceptions import RefreshNotValidError
 from google.cloud.sql.connector.rate_limiter import AsyncRateLimiter
 from google.cloud.sql.connector.refresh_utils import _is_valid
@@ -47,25 +47,23 @@ class RefreshAheadCache:
 
     def __init__(
         self,
-        instance_connection_string: str,
+        conn_name: ConnectionName,
         client: CloudSQLClient,
         keys: asyncio.Future,
         enable_iam_auth: bool = False,
     ) -> None:
         """Initializes a RefreshAheadCache instance.
 
         Args:
-            instance_connection_string (str): The Cloud SQL Instance's
-                connection string (also known as an instance connection name).
+            conn_name (ConnectionName): The Cloud SQL Instance's
+                connection name.
             client (CloudSQLClient): The Cloud SQL Client instance.
             keys (asyncio.Future): A future to the client's public-private key
                 pair.
             enable_iam_auth (bool): Enables automatic IAM database authentication
                 (Postgres and MySQL) as the default authentication method for all
                 connections.
         """
-        # validate and parse instance connection name
-        conn_name = _parse_instance_connection_name(instance_connection_string)
         self._project, self._region, self._instance = (
             conn_name.project,
             conn_name.region,

google/cloud/sql/connector/resolver.py

@@ -14,14 +14,15 @@
 
 from dns.asyncresolver import Resolver
 
-from google.cloud.sql.connector.instance import _parse_instance_connection_name
+from google.cloud.sql.connector.connection_name import _parse_instance_connection_name
+from google.cloud.sql.connector.exceptions import DnsResolutionError
 
 
 class DefaultResolver:
     """DefaultResolver simply validates and parses instance connection name."""
 
-    async def resolve(connection_name: str) -> str:
-        pass
+    async def resolve(self, connection_name: str) -> str:
+        return _parse_instance_connection_name(connection_name)
 
 
 class DnsResolver(Resolver):
@@ -30,8 +31,23 @@ class DnsResolver(Resolver):
     TXT records in DNS.
     """
 
-    pass
-
-
-async def resolve(dns: str) -> str:
-    pass
+    async def resolve(self, dns: str) -> str:
+        try:
+            conn_name = _parse_instance_connection_name(dns)
+        except ValueError:
+            # The connection name was not project:region:instance format.
+            # Attempt to query a TXT record to get connection name.
+            try:
+                result = await super().resolve(dns, "TXT", raise_on_no_answer=True)
+                if result is not None:
+                    rdata = result[0].to_text().strip('"')
+                    conn_name = _parse_instance_connection_name(rdata)
+            except ValueError:
+                raise DnsResolutionError(
+                    f"Unable to parse TXT for `{dns}` -> {result[0]}"
+                )
+            except Exception as e:
+                raise DnsResolutionError(
+                    f"Unable to resolve TXT record for `{dns}`"
+                ) from e
+        return conn_name