LegacyBackend: init

nixops/plugin.py

@@ -1,8 +1,9 @@
 from typing import Dict, Type
 import nixops.plugins
 from nixops.storage import StorageBackend
+from nixops.storage.legacy import LegacyBackend
 
 
 @nixops.plugins.hookimpl
 def register_backends() -> Dict[str, Type[StorageBackend]]:
-    return {}
+    return {"legacy": LegacyBackend}

nixops/script_defs.py

@@ -83,7 +83,6 @@ def network_state(args: Namespace) -> Generator[nixops.statefile.StateFile, None
     with TemporaryDirectory("nixops") as statedir:
         statefile = statedir + "/state.nixops"
         storage.fetchToFile(statefile)
-
         state = nixops.statefile.StateFile(statefile)
         try:
             storage.onOpen(state)

nixops/storage/legacy.py

@@ -0,0 +1,55 @@
+from nixops.storage import StorageArgDescriptions, StorageArgValues
+import nixops.statefile
+import sys
+import os
+import os.path
+
+
+class LegacyBackend:
+    @staticmethod
+    def arguments() -> StorageArgDescriptions:
+        raise NotImplementedError
+
+    def __init__(self, args: StorageArgValues) -> None:
+        pass
+
+    # fetchToFile: acquire a lock and download the state file to
+    # the local disk. Note: no arguments will be passed over kwargs.
+    # Making it part of the type definition allows adding new
+    # arguments later.
+    def fetchToFile(self, path: str, **kwargs) -> None:
+        os.symlink(os.path.abspath(self.state_location()), path)
+
+    def onOpen(self, sf: nixops.statefile.StateFile, **kwargs) -> None:
+        pass
+
+    def state_location(self) -> str:
+        env_override = os.environ.get("NIXOPS_STATE", os.environ.get("CHARON_STATE"))
+        if env_override is not None:
+            return env_override
+
+        home_dir = os.environ.get("HOME", "")
+        charon_dir = f"{home_dir}/.charon"
+        nixops_dir = f"{home_dir}/.nixops"
+
+        if not os.path.exists(nixops_dir):
+            if os.path.exists(charon_dir):
+                sys.stderr.write(
+                    "renaming ‘{0}’ to ‘{1}’...\n".format(charon_dir, nixops_dir)
+                )
+                os.rename(charon_dir, nixops_dir)
+                if os.path.exists(nixops_dir + "/deployments.charon"):
+                    os.rename(
+                        nixops_dir + "/deployments.charon",
+                        nixops_dir + "/deployments.nixops",
+                    )
+            else:
+                os.makedirs(nixops_dir, 0o700)
+
+        return nixops_dir + "/deployments.nixops"
+
+    # uploadFromFile: upload the new state file and release any locks
+    # Note: no arguments will be passed over kwargs. Making it part of
+    # the type definition allows adding new arguments later.
+    def uploadFromFile(self, path: str, **kwargs) -> None:
+        pass