Merge pull request #300 from jrbourbeau/auto-login

Support automatic authentication

README.md

@@ -70,22 +70,24 @@ The only requirement to use this library is to open a free account with NASA [ED
 
 ### **Authentication**
 
-Once you have an EDL account, you can authenticate using one of the following three methods:
+By default, `earthaccess` with automatically look for your EDL account credentials in two locations:
 
-1. Using a `.netrc` file
-    * Can use *earthaccess* to read your EDL credentials (username and password) from a `.netrc` file
-2. Reading your EDL credentials from environment variables
-    * if available you can use environment variables **EARTHDATA_USERNAME** and **EARTHDATA_PASSWORD**
-3. Interactively entering your EDL credentials
-    * You can be prompted for these credentials and save them to a `.netrc` file
+1. A `~/.netrc` file
+2. `EARTHDATA_USERNAME` and `EARTHDATA_PASSWORD` environment variables
+
+If neither of these options are configured, you can authenticate by calling the `earthaccess.login()` method
+and manually entering your EDL account credentials.
 
 ```python
 import earthaccess
 
-auth = earthaccess.login()
-
+earthaccess.login()
 ```
 
+Note you can pass `persist=True` to `earthaccess.login()` to have the EDL account credentials you enter
+automatically saved to a `~/.netrc` file for future use. 
+
+
 Once you are authenticated with NASA EDL you can:
 
 * Get a file from a DAAC using a `fsspec` session.

earthaccess/__init__.py

@@ -1,3 +1,5 @@
+import logging
+import threading
 from importlib.metadata import version
 from typing import Any
 
@@ -19,6 +21,8 @@
 from .search import DataCollections, DataGranules
 from .store import Store
 
+logger = logging.getLogger(__name__)
+
 __all__ = [
     "login",
     "search_datasets",
@@ -38,7 +42,42 @@
     "auth_environ",
 ]
 
-__auth__ = Auth()
-__store__: Any = None
-
 __version__ = version("earthaccess")
+
+_auth = Auth()
+_store = None
+_lock = threading.Lock()
+
+
+def __getattr__(name):  # type: ignore
+    """
+    Module-level getattr to handle automatic authentication when accessing
+    `earthaccess.__auth__` and `earthaccess.__store__`.
+
+    Other unhandled attributes raise as `AttributeError` as expected.
+    """
+    global _auth, _store
+
+    if name == "__auth__" or name == "__store__":
+        with _lock:
+            if not _auth.authenticated:
+                for strategy in ["environment", "netrc"]:
+                    try:
+                        _auth.login(strategy=strategy)
+                    except Exception as e:
+                        logger.debug(
+                            f"An error occurred during automatic authentication with {strategy=}: {str(e)}"
+                        )
+                        continue
+                    else:
+                        if not _auth.authenticated:
+                            continue
+                        else:
+                            _store = Store(_auth)
+                            logger.debug(
+                                f"Automatic authentication with {strategy=} was successful"
+                            )
+                            break
+            return _auth if name == "__auth__" else _store
+    else:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

earthaccess/auth.py

@@ -1,4 +1,5 @@
 import getpass
+import logging
 import os
 from netrc import NetrcParseError
 from pathlib import Path
@@ -10,6 +11,8 @@
 
 from .daac import DAACS
 
+logger = logging.getLogger(__name__)
+
 
 class SessionWithHeaderRedirection(requests.Session):
     """
@@ -76,7 +79,7 @@ def login(self, strategy: str = "netrc", persist: bool = False) -> Any:
             an instance of Auth.
         """
         if self.authenticated:
-            print("We are already authenticated with NASA EDL")
+            logger.debug("We are already authenticated with NASA EDL")
             return self
         if strategy == "interactive":
             self._interactive(persist)
@@ -98,7 +101,7 @@ def refresh_tokens(self) -> bool:
             if resp_tokens.ok:
                 self.token = resp_tokens.json()
                 self.tokens = [self.token]
-                print(
+                logger.debug(
                     f"earthaccess generated a token for CMR with expiration on: {self.token['expiration_date']}"
                 )
                 return True
@@ -111,7 +114,7 @@ def refresh_tokens(self) -> bool:
             if resp_tokens.ok:
                 self.token = resp_tokens.json()
                 self.tokens.extend(self.token)
-                print(
+                logger.debug(
                     f"earthaccess generated a token for CMR with expiration on: {self.token['expiration_date']}"
                 )
                 return True
@@ -127,7 +130,7 @@ def refresh_tokens(self) -> bool:
                 if resp_tokens.ok:
                     self.token = resp_tokens.json()
                     self.tokens[0] = self.token
-                    print(
+                    logger.debug(
                         f"earthaccess generated a token for CMR with expiration on: {self.token['expiration_date']}"
                     )
                     return True
@@ -230,7 +233,7 @@ def _interactive(self, presist_credentials: bool = False) -> bool:
         password = getpass.getpass(prompt="Enter your Earthdata password: ")
         authenticated = self._get_credentials(username, password)
         if authenticated:
-            print("Using user provided credentials for EDL")
+            logger.debug("Using user provided credentials for EDL")
             if presist_credentials:
                 print("Persisting credentials to .netrc")
                 self._persist_user_credentials(username, password)
@@ -240,29 +243,29 @@ def _netrc(self) -> bool:
         try:
             my_netrc = Netrc()
         except FileNotFoundError as err:
-            print(f"No .netrc found in {os.path.expanduser('~')}")
-            raise err
+            raise FileNotFoundError(
+                f"No .netrc found in {os.path.expanduser('~')}"
+            ) from err
         except NetrcParseError as err:
-            print("Unable to parse .netrc")
-            raise err
+            raise NetrcParseError("Unable to parse .netrc") from err
         if my_netrc["urs.earthdata.nasa.gov"] is not None:
             username = my_netrc["urs.earthdata.nasa.gov"]["login"]
             password = my_netrc["urs.earthdata.nasa.gov"]["password"]
         else:
             return False
         authenticated = self._get_credentials(username, password)
         if authenticated:
-            print("Using .netrc file for EDL")
+            logger.debug("Using .netrc file for EDL")
         return authenticated
 
     def _environment(self) -> bool:
         username = os.getenv("EARTHDATA_USERNAME")
         password = os.getenv("EARTHDATA_PASSWORD")
         authenticated = self._get_credentials(username, password)
         if authenticated:
-            print("Using environment variables for EDL")
+            logger.debug("Using environment variables for EDL")
         else:
-            print(
+            logger.debug(
                 "EARTHDATA_USERNAME and EARTHDATA_PASSWORD are not set in the current environment, try "
                 "setting them or use a different strategy (netrc, interactive)"
             )
@@ -279,7 +282,7 @@ def _get_credentials(
                     f"Authentication with Earthdata Login failed with:\n{token_resp.text}"
                 )
                 return False
-            print("You're now authenticated with NASA Earthdata Login")
+            logger.debug("You're now authenticated with NASA Earthdata Login")
             self.username = username
             self.password = password
 
@@ -288,13 +291,13 @@ def _get_credentials(
 
             if len(self.tokens) == 0:
                 self.refresh_tokens()
-                print(
+                logger.debug(
                     f"earthaccess generated a token for CMR with expiration on: {self.token['expiration_date']}"
                 )
                 self.token = self.tokens[0]
             elif len(self.tokens) > 0:
                 self.token = self.tokens[0]
-                print(
+                logger.debug(
                     f"Using token with expiration date: {self.token['expiration_date']}"
                 )
             profile = self.get_user_profile()