Abstract provider interface to keyring

Author: judahrand

src/pip/_internal/network/auth.py

@@ -4,10 +4,12 @@
 providing credentials in the context of network requests.
 """
 
+import os
 import shutil
 import subprocess
 import urllib.parse
-from typing import Any, Dict, List, NamedTuple, Optional, Tuple
+from abc import ABC, abstractmethod
+from typing import Any, Dict, List, NamedTuple, Optional, Tuple, Type
 
 from pip._vendor.requests.auth import AuthBase, HTTPBasicAuth
 from pip._vendor.requests.models import Request, Response
@@ -27,89 +29,157 @@
 
 
 class Credentials(NamedTuple):
-    service_name: str
+    url: str
     username: str
     password: str
 
 
-class KeyRingCli:
-    """Mirror the parts of keyring's API which pip uses
+class KeyRingBaseProvider(ABC):
+    """Keyring base provider interface"""
+
+    @classmethod
+    @abstractmethod
+    def is_available(cls) -> bool:
+        ...
+
+    @classmethod
+    @abstractmethod
+    def get_auth_info(cls, url: str, username: Optional[str]) -> Optional[AuthInfo]:
+        ...
+
+    @classmethod
+    @abstractmethod
+    def save_auth_info(cls, url: str, username: str, password: str) -> None:
+        ...
+
+
+class KeyRingPythonProvider(KeyRingBaseProvider):
+    """Keyring interface which uses locally imported `keyring`"""
+
+    try:
+        import keyring
+    except ImportError:
+        keyring = None  # type: ignore[assignment]
+
+    @classmethod
+    def is_available(cls) -> bool:
+        return cls.keyring is not None
+
+    @classmethod
+    def get_auth_info(cls, url: str, username: Optional[str]) -> Optional[AuthInfo]:
+        if cls.is_available is False:
+            return None
+
+        # Support keyring's get_credential interface which supports getting
+        # credentials without a username. This is only available for
+        # keyring>=15.2.0.
+        if hasattr(cls.keyring, "get_credential"):
+            logger.debug("Getting credentials from keyring for %s", url)
+            cred = cls.keyring.get_credential(url, username)
+            if cred is not None:
+                return cred.username, cred.password
+            return None
+
+        if username is not None:
+            logger.debug("Getting password from keyring for %s", url)
+            password = cls.keyring.get_password(url, username)
+            if password:
+                return username, password
+        return None
+
+    @classmethod
+    def save_auth_info(cls, url: str, username: str, password: str) -> None:
+        cls.keyring.set_password(url, username, password)
+
+
+class KeyRingCliProvider(KeyRingBaseProvider):
+    """Provider which uses `keyring` cli
 
     Instead of calling the keyring package installed alongside pip
     we call keyring on the command line which will enable pip to
     use which ever installation of keyring is available first in
     PATH.
     """
 
-    def __init__(self, keyring: str) -> None:
-        self.keyring = keyring
+    keyring = shutil.which("keyring")
+
+    @classmethod
+    def is_available(cls) -> bool:
+        return cls.keyring is not None
 
-    def get_password(self, service_name: str, username: str) -> Optional[str]:
-        cmd = [self.keyring, "get", service_name, username]
+    @classmethod
+    def get_auth_info(cls, url: str, username: Optional[str]) -> Optional[AuthInfo]:
+        if cls.is_available is False:
+            return None
+
+        # This is the default implementation of keyring.get_credential
+        # https://github.com/jaraco/keyring/blob/97689324abcf01bd1793d49063e7ca01e03d7d07/keyring/backend.py#L134-L139
+        if username is not None:
+            password = cls._get_password(url, username)
+            if password is not None:
+                return username, password
+        return None
+
+    @classmethod
+    def save_auth_info(cls, url: str, username: str, password: str) -> None:
+        if not cls.is_available:
+            raise RuntimeError("keyring is not available")
+        return cls._set_password(url, username, password)
+
+    @classmethod
+    def _get_password(cls, service_name: str, username: str) -> Optional[str]:
+        """Mirror the implemenation of keyring.get_password using cli"""
+        if cls.keyring is None:
+            return None
+
+        cmd = [cls.keyring, "get", service_name, username]
+        env = os.environ
+        env["PYTHONIOENCODING"] = "utf-8"
         res = subprocess.run(
             cmd,
             stdin=subprocess.DEVNULL,
             capture_output=True,
-            env=dict(PYTHONIOENCODING="utf-8"),
+            env=env,
         )
         if res.returncode:
             return None
         return res.stdout.decode("utf-8").strip("\n")
 
-    def set_password(self, service_name: str, username: str, password: str) -> None:
-        cmd = [self.keyring, "set", service_name, username]
+    @classmethod
+    def _set_password(cls, service_name: str, username: str, password: str) -> None:
+        """Mirror the implemenation of keyring.set_password using cli"""
+        if cls.keyring is None:
+            return None
+
+        cmd = [cls.keyring, "set", service_name, username]
         input_ = password.encode("utf-8") + b"\n"
-        res = subprocess.run(cmd, input=input_, env=dict(PYTHONIOENCODING="utf-8"))
+        env = os.environ
+        env["PYTHONIOENCODING"] = "utf-8"
+        res = subprocess.run(cmd, input=input_, env=env)
         res.check_returncode()
         return None
 
 
-try:
-    import keyring
-except ImportError:
-    keyring = None  # type: ignore[assignment]
-    keyring_path = shutil.which("keyring")
-    if keyring_path is not None:
-        keyring = KeyRingCli(keyring_path)  # type: ignore[assignment]
-except Exception as exc:
-    logger.warning(
-        "Keyring is skipped due to an exception: %s",
-        str(exc),
-    )
-    keyring = None  # type: ignore[assignment]
+def get_keyring_provider() -> Optional[Type[KeyRingBaseProvider]]:
+    if KeyRingPythonProvider.is_available():
+        return KeyRingPythonProvider
+    if KeyRingCliProvider.is_available():
+        return KeyRingCliProvider
+    return None
 
 
 def get_keyring_auth(url: Optional[str], username: Optional[str]) -> Optional[AuthInfo]:
     """Return the tuple auth for a given url from keyring."""
-    global keyring
-    if not url or not keyring:
+    # Do nothing if no url was provided
+    if not url:
         return None
 
-    try:
-        try:
-            get_credential = keyring.get_credential
-        except AttributeError:
-            pass
-        else:
-            logger.debug("Getting credentials from keyring for %s", url)
-            cred = get_credential(url, username)
-            if cred is not None:
-                return cred.username, cred.password
-            return None
-
-        if username:
-            logger.debug("Getting password from keyring for %s", url)
-            password = keyring.get_password(url, username)
-            if password:
-                return username, password
+    keyring = get_keyring_provider()
+    # Do nothin if keyring is not available
+    if keyring is None:
+        return None
 
-    except Exception as exc:
-        logger.warning(
-            "Keyring is skipped due to an exception: %s",
-            str(exc),
-        )
-        keyring = None  # type: ignore[assignment]
-    return None
+    return keyring.get_auth_info(url, username)
 
 
 class MultiDomainBasicAuth(AuthBase):
@@ -283,7 +353,7 @@ def _prompt_for_password(
 
     # Factored out to allow for easy patching in tests
     def _should_save_password_to_keyring(self) -> bool:
-        if not keyring:
+        if get_keyring_provider() is None:
             return False
         return ask("Save credentials to keyring [y/N]: ", ["y", "n"]) == "y"
 
@@ -319,7 +389,7 @@ def handle_401(self, resp: Response, **kwargs: Any) -> Response:
             # Prompt to save the password to keyring
             if save and self._should_save_password_to_keyring():
                 self._credentials_to_save = Credentials(
-                    service_name=parsed.netloc,
+                    url=parsed.netloc,
                     username=username,
                     password=password,
                 )
@@ -355,15 +425,16 @@ def warn_on_401(self, resp: Response, **kwargs: Any) -> None:
 
     def save_credentials(self, resp: Response, **kwargs: Any) -> None:
         """Response callback to save credentials on success."""
+        keyring = get_keyring_provider()
         assert keyring is not None, "should never reach here without keyring"
         if not keyring:
-            return
+            return None
 
         creds = self._credentials_to_save
         self._credentials_to_save = None
         if creds and resp.status_code < 400:
             try:
                 logger.info("Saving credentials to keyring")
-                keyring.set_password(creds.service_name, creds.username, creds.password)
+                keyring.save_auth_info(creds.url, creds.username, creds.password)
             except Exception:
                 logger.exception("Failed to save credentials")