Allow non-federated keyring generation to use etherbase as a default via node backend

nucypher/cli/characters/felix.py

@@ -76,9 +76,6 @@ def felix(click_config,
             click.prompt(f"New geth address is {new_checksum_address}. \n"
                          f"Press ENTER key to continue", default=True)
 
-        elif not checksum_address:
-            raise click.BadArgumentUsage('--checksum-address is required to initialize a new Felix configuration.')
-
         new_felix_config = FelixConfiguration.generate(password=new_password,
                                                        config_root=config_root,
                                                        rest_host=host,

nucypher/cli/characters/ursula.py

@@ -198,7 +198,7 @@ def ursula(click_config,
     if dev:
 
         ETH_NODE = NuCypherGethDevProcess()
-        ETH_NODE.start()()
+        ETH_NODE.start()
         provider_uri = ETH_NODE.provider_uri
 
         ursula_config = UrsulaConfiguration(dev_mode=True,
@@ -304,7 +304,6 @@ def ursula(click_config,
     URSULA = ursula_config(password=password, known_nodes=teacher_nodes, lonely=lonely)
     del password  # ... under the rug
 
-
     #
     # Authenticated Action Switch
     #
@@ -336,7 +335,7 @@ def ursula(click_config,
                 stdio.StandardIO(UrsulaCommandProtocol(ursula=URSULA))
 
             if dry_run:
-                return  # <-- ABORT -X (Last Chance)
+                return  # <-- ABORT - (Last Chance)
 
             # Run - Step 3
             node_deployer = URSULA.get_deployer()

nucypher/config/keyring.py

@@ -123,6 +123,8 @@ def _write_private_keyfile(keypath: str,
     ---------------------------------------------------------------------
     """
 
+    if os.path.isfile(keypath):
+        raise RuntimeError(f"Private keyfile {keypath} already exists.")
     try:
         keyfile_descriptor = os.open(keypath, flags=__PRIVATE_FLAGS, mode=__PRIVATE_MODE)
     finally:
@@ -530,7 +532,7 @@ class NucypherKeyring:
         if curve is None:
             curve = cls.__DEFAULT_TLS_CURVE
 
-        if checksum_address is not None and not is_checksum_address(checksum_address):
+        if checksum_address and not is_checksum_address(checksum_address):
             raise ValueError(f"{checksum_address} is not a valid ethereum checksum address")
 
         _base_filepaths = cls._generate_base_filepaths(keyring_root=keyring_root)

nucypher/config/node.py

@@ -617,21 +617,32 @@ class NodeConfiguration(ABC):
                                        *args, **kwargs)
 
     def write_keyring(self, password: str, **generation_kwargs) -> NucypherKeyring:
-
+        # Get or create wallet address
         if not self.federated_only and not self.checksum_public_address:
-            if self.geth:
+            try:
-                data_dir = os.path.join(self.config_root, '.ethereum', NuCypherGethDevnetProcess._CHAIN_NAME)
-                etherbase = NuCypherGethDevnetProcess.ensure_account_exists(password=password, data_dir=data_dir)
-
                 checksum_address = self.blockchain.interface.w3.eth.accounts[0]  # etherbase
-        else:
+            except IndexError:
+                client_version = self.interface.w3.clientVersion
+                if 'Geth' in client_version:
+                    data_dir = os.path.join(self.config_root, '.ethereum', NuCypherGethDevnetProcess._CHAIN_NAME)
+                    checksum_address = NuCypherGethDevnetProcess.ensure_account_exists(password=password, data_dir=data_dir)
+
+        # Use explicit address
+        elif self.checksum_public_address:
             checksum_address = self.checksum_public_address
 
+        # Generate a federated checksum address
+        elif self.federated_only and not self.checksum_public_address:
+            checksum_address = None
+
+        else:
+            raise RuntimeError("Something wonderful is happening")  # FIXME: Flow control here is a mess
+
         self.keyring = NucypherKeyring.generate(password=password,
                                                 keyring_root=self.keyring_dir,
                                                 checksum_address=checksum_address,
                                                 **generation_kwargs)
-        # Operating mode switch TODO: #466
+        # Operating mode switch
         if self.federated_only:
             self.checksum_public_address = self.keyring.federated_address
         else: