Split out the local backend (#2052)

This splits the backend into two parts: the local backend for desktop cellxgene and the AWS backend for hosted cellxgene. The local backend is in local_server while the hosted remains in server. The general idea is to copy everything from server to local_server, pull unneeded stuff out of local_server, and keep server as-is for this PR. Not touching server means all the infra and deployment code will continue working just as it did before so we can make those changes incrementally.

local_server/auth/__init__.py

@@ -0,0 +1,5 @@
+# import the built in auth types so they can be registered
+
+import local_server.auth.auth_none  # noqa: F401
+import local_server.auth.auth_test  # noqa: F401
+import local_server.auth.auth_session  # noqa: F401

local_server/auth/auth.py

@@ -0,0 +1,91 @@
+from abc import ABC, abstractmethod
+
+
+class AuthTypeBase(ABC):
+    """Base type for all authentication types."""
+
+    def __init__(self):
+        super().__init__()
+
+    @abstractmethod
+    def is_valid_authentication_type(self):
+        """Return True if the auth type is valid, e.g. it can return userinfo and username.
+          (AuthTypeNone is the only one type that returns False)"""
+        pass
+
+    def requires_client_login(self):
+        """Return True if the user needs to login from the client (e.g. Login button is shown)"""
+        return False
+
+    @abstractmethod
+    def complete_setup(self, app):
+        """complete any setup that may be needed by this auth type.  The Flask app is passed in.
+        This is the last auth function called before the server starts to run."""
+        pass
+
+    @abstractmethod
+    def is_user_authenticated(self):
+        """Return True if the user is authenticated"""
+        pass
+
+    @abstractmethod
+    def get_user_id(self):
+        """Return the id for this user (string)"""
+        pass
+
+    @abstractmethod
+    def get_user_name(self):
+        """Return the name of the user (string)"""
+        pass
+
+    @abstractmethod
+    def get_user_email(self):
+        """Return the name of the user (string)"""
+        pass
+
+    def get_user_picture(self):
+        """Return the location to the user's picture"""
+        return None
+
+
+class AuthTypeClientBase(AuthTypeBase):
+    """Base type for all authentication types that require the client to login"""
+
+    def __init__(self):
+        super().__init__()
+
+    def requires_client_login(self):
+        return True
+
+    @abstractmethod
+    def add_url_rules(self, selfapp):
+        """Add url rules to the app (like /login, /logout, etc)"""
+        pass
+
+    @abstractmethod
+    def get_login_url(self, data_adaptor):
+        """Return the url for the login route"""
+        pass
+
+    @abstractmethod
+    def get_logout_url(self, data_adaptor):
+        """Return the url for the logout route"""
+        pass
+
+
+class AuthTypeFactory:
+    """Factory class to create an authentication type"""
+
+    auth_types = {}
+
+    @staticmethod
+    def register(name, auth_type):
+        assert issubclass(auth_type, AuthTypeBase)
+        AuthTypeFactory.auth_types[name] = auth_type
+
+    @staticmethod
+    def create(name, app_config):
+        auth_type = AuthTypeFactory.auth_types.get(name)
+        if auth_type is None:
+            return None
+        return auth_type(app_config)

local_server/auth/auth_none.py

@@ -0,0 +1,27 @@
+from local_server.auth.auth import AuthTypeBase, AuthTypeFactory
+
+
+class AuthTypeNone(AuthTypeBase):
+    def __init__(self, app_config):
+        super().__init__()
+
+    def is_valid_authentication_type(self):
+        return False
+
+    def complete_setup(self, app):
+        pass
+
+    def is_user_authenticated(self):
+        return True
+
+    def get_user_id(self):
+        return None
+
+    def get_user_name(self):
+        return None
+
+    def get_user_email(self):
+        return None
+
+
+AuthTypeFactory.register(None, AuthTypeNone)

local_server/auth/auth_session.py

@@ -0,0 +1,39 @@
+from local_server.auth.auth import AuthTypeBase, AuthTypeFactory
+from flask import session
+from uuid import uuid4
+
+
+class AuthTypeSession(AuthTypeBase):
+    """Session based authentication.  The user is always logged.  The user id is a random number
+    associated with the session.  This is a good choice for desktop servers."""
+
+    # key in the session token for userid
+    CXGUID = "cxguid"
+
+    def __init__(self, app_config):
+        super().__init__()
+
+    def is_valid_authentication_type(self):
+        return True
+
+    def complete_setup(self, app):
+        pass
+
+    def is_user_authenticated(self):
+        # always authenticated
+        return True
+
+    def get_user_id(self):
+        if self.CXGUID not in session:
+            session[self.CXGUID] = uuid4().hex
+            session.permanent = True
+        return session[self.CXGUID]
+
+    def get_user_name(self):
+        return "anonymous"
+
+    def get_user_email(self):
+        return None
+
+
+AuthTypeFactory.register("session", AuthTypeSession)

local_server/auth/auth_test.py

@@ -0,0 +1,73 @@
+from local_server.auth.auth import AuthTypeClientBase, AuthTypeFactory
+from flask import session, request, redirect
+
+
+class AuthTypeTest(AuthTypeClientBase):
+    """An authentication type for testing client based logins.  When the login route is accessed
+    the user is automatically logged in with a default or configured username"""
+
+    # key in session token with userid and username
+    CXGUID = "cxguid_test"
+    CXGUNAME = "cxguname_test"
+    CXGUEMAIL = "cxguemail_test"
+    CXGUPICTURE = "cxgupicture_test"
+
+    def __init__(self, app_config):
+        super().__init__()
+        self.user_name = "test_account"
+        self.user_id = "id0001"
+        self.user_email = "test_account@test.com"
+        self.user_picture = None
+
+    def is_valid_authentication_type(self):
+        return True
+
+    def requires_client_login(self):
+        return True
+
+    def add_url_rules(self, app):
+        app.add_url_rule("/login", "login", self.login, methods=["GET"])
+        app.add_url_rule("/logout", "logout", self.logout, methods=["GET"])
+
+    def complete_setup(self, app):
+        pass
+
+    def is_user_authenticated(self):
+        return self.CXGUID in session
+
+    def get_user_id(self):
+        return session.get(self.CXGUID)
+
+    def get_user_name(self):
+        return session.get(self.CXGUNAME)
+
+    def get_user_email(self):
+        return session.get(self.CXGUEMAIL)
+
+    def get_user_picture(self):
+        return session.get(self.CXGUPICTURE)
+
+    def login(self):
+        args = request.args
+        return_to = args.get("dataset", "/")
+        session[self.CXGUID] = args.get("userid", self.user_id)
+        session[self.CXGUNAME] = args.get("username", self.user_name)
+        session[self.CXGUEMAIL] = args.get("email", self.user_email)
+        session[self.CXGUPICTURE] = args.get("picture", self.user_picture)
+        return redirect(return_to)
+
+    def logout(self):
+        session.clear()
+        return_to = request.args.get("dataset", "/")
+        return redirect(return_to)
+
+    def get_login_url(self, data_adaptor):
+        """Return the url for the login route"""
+        return "/login"
+
+    def get_logout_url(self, data_adaptor):
+        """Return the url for the logout route"""
+        return "/logout"
+
+
+AuthTypeFactory.register("test", AuthTypeTest)