Update the "SSH key" feature flag in `--version` output (0b62585) - derivepassphrase.git

Update the "SSH key" feature flag in `--version` output

Marco Ricci commited on 2025-08-02 14:26:22
Zeige 1 geänderte Dateien mit 30 Einfügungen und 3 Löschungen.

Change the feature detection system to actually test whether it can
successfully construct an SSH agent client, and then report that the
feature is available (or not) based on the success of this test.

Previously, `derivepassphrase` would determine whether it supported
connecting to an SSH agent or not by checking for Python support for
UNIX domain sockets.  This was the same criteria as used by the actual
SSH agent client constructor to attempt, well, constructing an SSH agent
client.  However, since the SSH agent client now delegates the
construction to the socket provider mechanism, which includes fallbacks
and "available, but not sensibly callable" providers, determining
whether SSH agent support is available is not quite as straight-forward
anymore as testing for `socket.AF_UNIX` was.

I could attempt to replicate the registry entry resolving steps to see
if we have a working socket provider, but even that entails actually
running the provider and checking for the absence of certain kinds of
exceptions (but not other kinds, which indicate a manner of success!).
Plus, a separate, indepedent replication of the search logic runs the
risk of becoming desynchronized with the original implementation:
`derivepassphrase vault --version` thinks that support is or is not
available, and the SSH agent client constructor thinks the opposite.

A *far* more robust solution is to actually test the functionality we
are hoping to use directly, i.e., to test constructing an SSH agent
client: it obviously doesn't work if we don't have support, and if it
does work, we have support.  (This technique would of course generalize
to other feature flags, if we had any such.)  So that's what we'll do.

src/derivepassphrase/_internals/cli_machinery.py 6f8f96e..b39e443

src/derivepassphrase/_internals/cli_machinery.py

Zeige Datei @ 0b62585

@@ -18,17 +18,21 @@ import collections
 import importlib.metadata
 import inspect
 import logging
-import socket
+import sys
 import warnings
 from typing import TYPE_CHECKING, Callable, Literal, TextIO, TypeVar
 
 import click
 import click.shell_completion
+import exceptiongroup
 from typing_extensions import Any, ParamSpec, override
 
-from derivepassphrase import _internals, _types
+from derivepassphrase import _internals, _types, ssh_agent
 from derivepassphrase._internals import cli_messages as _msg
 
+if sys.version_info < (3, 11):
+    from exceptiongroup import BaseExceptionGroup
+
 if TYPE_CHECKING:
     import types
     from collections.abc import (
@@ -1140,6 +1144,29 @@ def export_vault_version_option_callback(
         ctx.exit()
 
 
+def _test_for_ssh_key_feature() -> bool:
+    """Return true if we support SSH keys.
+
+    This is the feature test for [`_types.Feature.SSH_KEY`][].  We test
+    this by attempting to construct an SSH agent client, reporting
+    whether this can principally work, or not.
+
+    """
+    ret = True
+
+    def handle_notimplementederror(_exc: BaseExceptionGroup) -> None:
+        nonlocal ret
+        ret = False
+
+    with exceptiongroup.catch({  # noqa: SIM117
+        NotImplementedError: handle_notimplementederror,
+        Exception: lambda _exc: None,
+    }):
+        with ssh_agent.SSHAgentClient.ensure_agent_subcontext():
+            pass
+    return ret
+
+
 def vault_version_option_callback(
     ctx: click.Context,
     param: click.Parameter,
@@ -1148,7 +1175,7 @@ def vault_version_option_callback(
     if value and not ctx.resilient_parsing:
         common_version_output(ctx, param, value)
         features = {
-            _types.Feature.SSH_KEY: hasattr(socket, 'AF_UNIX'),
+            _types.Feature.SSH_KEY: _test_for_ssh_key_feature(),
         }
         click.echo()
         version_info_types: dict[_msg.Label, list[str]] = {


...	...	@@ -18,17 +18,21 @@ import collections
18	18	import importlib.metadata
19	19	import inspect
20	20	import logging
21		-import socket
	21	+import sys
22	22	import warnings
23	23	from typing import TYPE_CHECKING, Callable, Literal, TextIO, TypeVar
24	24
25	25	import click
26	26	import click.shell_completion
	27	+import exceptiongroup
27	28	from typing_extensions import Any, ParamSpec, override
28	29
29		-from derivepassphrase import _internals, _types
	30	+from derivepassphrase import _internals, _types, ssh_agent
30	31	from derivepassphrase._internals import cli_messages as _msg
31	32
	33	+if sys.version_info < (3, 11):
	34	+ from exceptiongroup import BaseExceptionGroup
	35	+
32	36	if TYPE_CHECKING:
33	37	import types
34	38	from collections.abc import (
...	...	@@ -1140,6 +1144,29 @@ def export_vault_version_option_callback(
1140	1144	ctx.exit()
1141	1145
1142	1146
	1147	+def _test_for_ssh_key_feature() -> bool:
	1148	+ """Return true if we support SSH keys.
	1149	+
	1150	+ This is the feature test for [`_types.Feature.SSH_KEY`][]. We test
	1151	+ this by attempting to construct an SSH agent client, reporting
	1152	+ whether this can principally work, or not.
	1153	+
	1154	+ """
	1155	+ ret = True
	1156	+
	1157	+ def handle_notimplementederror(_exc: BaseExceptionGroup) -> None:
	1158	+ nonlocal ret
	1159	+ ret = False
	1160	+
	1161	+ with exceptiongroup.catch({ # noqa: SIM117
	1162	+ NotImplementedError: handle_notimplementederror,
	1163	+ Exception: lambda _exc: None,
	1164	+ }):
	1165	+ with ssh_agent.SSHAgentClient.ensure_agent_subcontext():
	1166	+ pass
	1167	+ return ret
	1168	+
	1169	+
1143	1170	def vault_version_option_callback(
1144	1171	ctx: click.Context,
1145	1172	param: click.Parameter,
...	...	@@ -1148,7 +1175,7 @@ def vault_version_option_callback(
1148	1175	if value and not ctx.resilient_parsing:
1149	1176	common_version_output(ctx, param, value)
1150	1177	features = {
1151		- _types.Feature.SSH_KEY: hasattr(socket, 'AF_UNIX'),
	1178	+ _types.Feature.SSH_KEY: _test_for_ssh_key_feature(),
1152	1179	}
1153	1180	click.echo()
1154	1181	version_info_types: dict[_msg.Label, list[str]] = {
1155	1182