kubeadm: detect empty token lists

Fix #58116

changelog/58116.fixed

@@ -0,0 +1 @@
+Fix kubeadm token_list when the list of tokens is empty

salt/modules/kubeadm.py

@@ -328,20 +328,21 @@ def token_list(kubeconfig=None, rootfs=None):
 
     lines = _cmd(cmd).splitlines()
 
-    # Find the header and parse it.  We do not need to validate the
-    # content, as the regex will take care of future changes.
-    header = lines.pop(0)
-    header = [i.lower() for i in re.findall(r"(\w+(?:\s\w+)*)", header)]
-
     tokens = []
-    for line in lines:
-        # TODO(aplanas): descriptions with multiple spaces can break
-        # the parser.
-        values = re.findall(r"(\S+(?:\s\S+)*)", line)
-        if len(header) != len(values):
-            log.error("Error parsing line: {}".format(line))
-            continue
-        tokens.append({key: value for key, value in zip(header, values)})
+    if lines:
+        # Find the header and parse it.  We do not need to validate
+        # the content, as the regex will take care of future changes.
+        header = lines.pop(0)
+        header = [i.lower() for i in re.findall(r"(\w+(?:\s\w+)*)", header)]
+
+        for line in lines:
+            # TODO(aplanas): descriptions with multiple spaces can
+            # break the parser.
+            values = re.findall(r"(\S+(?:\s\S+)*)", line)
+            if len(header) != len(values):
+                log.error("Error parsing line: {}".format(line))
+                continue
+            tokens.append({key: value for key, value in zip(header, values)})
     return tokens
 
 

tests/unit/modules/test_kubeadm.py

@@ -1,7 +1,3 @@
-# -*- coding: utf-8 -*-
-
-from __future__ import absolute_import, print_function, unicode_literals
-
 import pytest
 import salt.modules.kubeadm as kubeadm
 from salt.exceptions import CommandExecutionError
@@ -227,6 +223,18 @@ class KubeAdmTestCase(TestCase, LoaderModuleMockMixin):
             with pytest.raises(CommandExecutionError):
                 assert kubeadm.token_generate()
 
+    def test_token_empty(self):
+        """
+        Test kuebadm.token_list when no outout
+        """
+        result = {"retcode": 0, "stdout": ""}
+        salt_mock = {
+            "cmd.run_all": MagicMock(return_value=result),
+        }
+        with patch.dict(kubeadm.__salt__, salt_mock):
+            assert kubeadm.token_list() == []
+            salt_mock["cmd.run_all"].assert_called_with(["kubeadm", "token", "list"])
+
     def test_token_list(self):
         """
         Test kuebadm.token_list without parameters