WIP: Add deploy without creating a state file

nixops/__main__.py

@@ -164,6 +164,7 @@
     help="activate unchanged configurations as well",
 )
 add_common_deployment_options(subparser)
+add_common_modify_options(subparser)
 
 subparser = add_subparser(subparsers, "send-keys", help="send encryption keys")
 subparser.set_defaults(op=op_send_keys)

nixops/evaluation.py

@@ -0,0 +1,44 @@
+from dataclasses import dataclass
+import subprocess
+import typing
+import json
+
+
+@dataclass
+class NetworkEval:
+
+    description: str = "Unnamed NixOps network"
+    enableRollback: bool = False
+    enableState: bool = True
+
+
+def _eval_attr(
+    attr, nix_exprs: typing.List[str]
+) -> typing.Dict[typing.Any, typing.Any]:
+    p = subprocess.run(
+        [
+            "nix-instantiate",
+            "--eval-only",
+            "--json",
+            "--strict",
+            # Arg
+            "--arg",
+            "checkConfigurationOptions",
+            "false",
+            # Attr
+            "-A",
+            attr,
+        ]
+        + nix_exprs,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+    if p.returncode != 0:
+        raise RuntimeError(p.stderr.decode())
+
+    return json.loads(p.stdout)
+
+
+def eval_network(nix_exprs: typing.List[str]) -> NetworkEval:
+    result = _eval_attr("network", nix_exprs)
+    return NetworkEval(**result)

nixops/script_defs.py

@@ -26,8 +26,10 @@
 from datetime import datetime
 from pprint import pprint
 import importlib
+from functools import lru_cache
 
 from nixops.plugins import get_plugin_manager
+from nixops.evaluation import eval_network
 
 
 pm = get_plugin_manager()
@@ -37,6 +39,11 @@
 ]
 
 
+@lru_cache()
+def _create_state(state_file: str) -> nixops.statefile.StateFile:
+    return nixops.statefile.StateFile(state_file)
+
+
 def op_list_plugins(args):
     if args.verbose:
         tbl = create_table([("Installed Plugins", "c"), ("Plugin Reference", "c")])
@@ -68,14 +75,14 @@ def sort_deployments(
 # $NIXOPS_DEPLOYMENT.
 def one_or_all(args: Namespace) -> List[nixops.deployment.Deployment]:
     if args.all:
-        sf = nixops.statefile.StateFile(args.state_file)
+        sf = _create_state(args.state_file)
         return sf.get_all_deployments()
     else:
         return [open_deployment(args)]
 
 
 def op_list_deployments(args):
-    sf = nixops.statefile.StateFile(args.state_file)
+    sf = _create_state(args.state_file)
     tbl = create_table(
         [
             ("UUID", "l"),
@@ -99,7 +106,7 @@ def op_list_deployments(args):
 
 
 def open_deployment(args):
-    sf = nixops.statefile.StateFile(args.state_file)
+    sf = _create_state(args.state_file)
     depl = sf.open_deployment(uuid=args.deployment)
 
     depl.extra_nix_path = sum(args.nix_path or [], [])
@@ -145,12 +152,19 @@ def modify_deployment(args, depl: nixops.deployment.Deployment):
 
 
 def op_create(args):
-    sf = nixops.statefile.StateFile(args.state_file)
+    sf = _create_state(args.state_file)
     depl = sf.create_deployment()
     sys.stderr.write("created deployment ‘{0}’\n".format(depl.uuid))
     modify_deployment(args, depl)
-    if args.name or args.deployment:
-        set_name(depl, args.name or args.deployment)
+
+    # When deployment is created without state "name" does not exist
+    name = args.deployment
+    if "name" in args:
+        name = args.name or args.deployment
+
+    if name:
+        set_name(depl, name)
+
     sys.stdout.write(depl.uuid + "\n")
 
 
@@ -284,7 +298,7 @@ def name_to_key(name: str) -> Tuple[str, str, List[object]]:
                 )
 
     if args.all:
-        sf = nixops.statefile.StateFile(args.state_file)
+        sf = _create_state(args.state_file)
         if not args.plain:
             tbl = create_table([("Deployment", "l")] + table_headers)
         for depl in sort_deployments(sf.get_all_deployments()):
@@ -553,7 +567,18 @@ def op_restore(args):
 
 
 def op_deploy(args):
+
+    # If nix expressions are passed evaluate the network first so we can figure
+    # out if we need to create state or not
+    if args.nix_exprs:
+        network = eval_network(args.nix_exprs)
+        # If state is not enabled we need to create the deployment first in the in-memory sqlite db
+        if not network.enableState:
+            args.state_file = ":memory:"
+            op_create(args)
+
     depl = open_deployment(args)
+
     if args.confirm:
         depl.logger.set_autoresponse("y")
     if args.evaluate_only:
@@ -710,7 +735,7 @@ def op_export(args):
 
 
 def op_import(args):
-    sf = nixops.statefile.StateFile(args.state_file)
+    sf = _create_state(args.state_file)
     existing = set(sf.query_deployments())
 
     dump = json.loads(sys.stdin.read())
@@ -1064,7 +1089,7 @@ def add_subparser(
     return subparser
 
 
-def add_common_modify_options(subparser: ArgumentParser):
+def add_common_modify_options(subparser: ArgumentParser) -> None:
     subparser.add_argument(
         "nix_exprs",
         nargs="*",
@@ -1081,7 +1106,7 @@ def add_common_modify_options(subparser: ArgumentParser):
     )
 
 
-def add_common_deployment_options(subparser: ArgumentParser):
+def add_common_deployment_options(subparser: ArgumentParser) -> None:
     subparser.add_argument(
         "--include",
         nargs="+",

nixops/statefile.py

@@ -82,7 +82,10 @@ class StateFile(object):
     def __init__(self, db_file: str) -> None:
         self.db_file: str = db_file
 
-        if os.path.splitext(db_file)[1] not in [".nixops", ".charon"]:
+        if db_file != ":memory:" and os.path.splitext(db_file)[1] not in [
+            ".nixops",
+            ".charon",
+        ]:
             raise Exception(
                 "state file ‘{0}’ should have extension ‘.nixops’".format(db_file)
             )