Fix minionfs raising when the minions cache dir is absent

changelog/50351.fixed.md

@@ -0,0 +1 @@
+salt-ssh: fix minionfs raising when minions cache dir is missing

salt/fileserver/minionfs.py

@@ -238,6 +238,13 @@ def file_list(load):
         prefix = prefix[len(mountpoint + os.path.sep) :]
 
     minions_cache_dir = os.path.join(__opts__["cachedir"], "minions")
+    if not os.path.isdir(minions_cache_dir):
+        # The minions cache dir may not exist yet (e.g. under the salt-ssh
+        # shim, where the cachedir is a fresh temp dir with no pushed files).
+        log.debug(
+            "minionfs: minions cache directory %s does not exist", minions_cache_dir
+        )
+        return []
     minion_dirs = os.listdir(minions_cache_dir)
 
     # If the prefix is not an empty string, then get the minion id from it. The
@@ -314,6 +321,13 @@ def dir_list(load):
         prefix = prefix[len(mountpoint + os.path.sep) :]
 
     minions_cache_dir = os.path.join(__opts__["cachedir"], "minions")
+    if not os.path.isdir(minions_cache_dir):
+        # The minions cache dir may not exist yet (e.g. under the salt-ssh
+        # shim, where the cachedir is a fresh temp dir with no pushed files).
+        log.debug(
+            "minionfs: minions cache directory %s does not exist", minions_cache_dir
+        )
+        return []
     minion_dirs = os.listdir(minions_cache_dir)
 
     # If the prefix is not an empty string, then get the minion id from it. The

tests/pytests/unit/fileserver/test_minionfs.py

@@ -0,0 +1,96 @@
+import os
+
+import pytest
+
+import salt.fileserver.minionfs as minionfs
+
+
+@pytest.fixture
+def configure_loader_modules(tmp_path):
+    opts = {
+        "cachedir": str(tmp_path),
+        "minionfs_env": "base",
+        "minionfs_mountpoint": "",
+        "minionfs_whitelist": [],
+        "minionfs_blacklist": [],
+        "file_ignore_regex": [],
+        "file_ignore_glob": [],
+    }
+    return {minionfs: {"__opts__": opts}}
+
+
+def test_file_list_missing_minions_cache_dir():
+    """
+    file_list should return an empty list rather than raising when the
+    minions cache directory does not exist (e.g. under the salt-ssh shim).
+    """
+    minions_cache_dir = os.path.join(minionfs.__opts__["cachedir"], "minions")
+    assert not os.path.isdir(minions_cache_dir)
+    assert minionfs.file_list({"saltenv": "base"}) == []
+
+
+def test_dir_list_missing_minions_cache_dir():
+    """
+    dir_list should return an empty list rather than raising when the
+    minions cache directory does not exist (e.g. under the salt-ssh shim).
+    """
+    minions_cache_dir = os.path.join(minionfs.__opts__["cachedir"], "minions")
+    assert not os.path.isdir(minions_cache_dir)
+    assert minionfs.dir_list({"saltenv": "base"}) == []
+
+
+def test_file_list_missing_minions_cache_dir_production_load_50351():
+    """
+    file_list must return an empty list rather than raising when the minions
+    cache directory is absent and the load carries the exact shape production
+    sends.
+    """
+    # Production callers (fileclient.RemoteClient.file_list ->
+    # Fileserver.file_list -> backend) always include a "prefix" key (and
+    # "cmd") in the load. A non-empty prefix is the decisive case: the
+    # prefix-to-minion-ID handling sits below the os.listdir() call that
+    # used to raise FileNotFoundError, so it was never reached.
+    load = {"saltenv": "base", "prefix": "webserver/etc", "cmd": "_file_list"}
+    minions_cache_dir = os.path.join(minionfs.__opts__["cachedir"], "minions")
+    assert not os.path.isdir(minions_cache_dir)
+    assert minionfs.file_list(load) == []
+
+
+def test_dir_list_missing_minions_cache_dir_production_load_50351():
+    """
+    dir_list must return an empty list rather than raising when the minions
+    cache directory is absent and the load carries the exact shape production
+    sends.
+    """
+    # Same production load shape as file_list: fileclient always sends
+    # "prefix" (and "cmd") alongside "saltenv".
+    load = {"saltenv": "base", "prefix": "webserver/etc", "cmd": "_dir_list"}
+    minions_cache_dir = os.path.join(minionfs.__opts__["cachedir"], "minions")
+    assert not os.path.isdir(minions_cache_dir)
+    assert minionfs.dir_list(load) == []
+
+
+def test_file_list_existing_minions_cache_dir_50351(tmp_path):
+    """
+    Guard against overcorrection: when the minions cache directory exists
+    and holds pushed files, the missing-directory guard must not kick in.
+    file_list must still return the pushed files.
+    """
+    files_dir = tmp_path / "minions" / "webserver" / "files" / "etc"
+    files_dir.mkdir(parents=True)
+    (files_dir / "some.conf").write_text("pushed")
+    load = {"saltenv": "base", "prefix": "", "cmd": "_file_list"}
+    assert minionfs.file_list(load) == [os.path.join("webserver", "etc", "some.conf")]
+
+
+def test_dir_list_existing_minions_cache_dir_50351(tmp_path):
+    """
+    Guard against overcorrection: when the minions cache directory exists
+    and holds pushed files, the missing-directory guard must not kick in.
+    dir_list must still return the pushed directories.
+    """
+    files_dir = tmp_path / "minions" / "webserver" / "files" / "etc"
+    files_dir.mkdir(parents=True)
+    (files_dir / "some.conf").write_text("pushed")
+    load = {"saltenv": "base", "prefix": "", "cmd": "_dir_list"}
+    assert minionfs.dir_list(load) == [os.path.join("webserver", "etc")]