Add new NVMe grain to display storage initiator

doc/ref/configuration/minion.rst

@@ -929,6 +929,20 @@ minion. Since this grain is expensive, it is disabled by default.
 
     iscsi_grains: True
 
+.. conf_minion:: nvme_grains
+
+``nvme_grains``
+------------------------
+
+Default: ``False``
+
+The ``nvme_grains`` setting will enable the ``nvme_nqn`` grain on the
+minion. Since this grain is expensive, it is disabled by default.
+
+.. code-block:: yaml
+
+    nvme_grains: True
+
 .. conf_minion:: mine_enabled
 
 ``mine_enabled``

salt/grains/nvme.py

@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+'''
+Grains for NVMe Qualified Names (NQN).
+
+.. versionadded:: Flourine
+
+To enable these grains set `nvme_grains: True`.
+
+.. code-block:: yaml
+
+    nvme_grains: True
+'''
+# Import Python libs
+from __future__ import absolute_import, print_function, unicode_literals
+
+import errno
+import logging
+
+# Import Salt libs
+import salt.utils.files
+import salt.utils.path
+import salt.utils.platform
+
+__virtualname__ = 'nvme'
+
+# Get logging started
+log = logging.getLogger(__name__)
+
+
+def __virtual__():
+    if __opts__.get('nvme_grains', False) is False:
+        return False
+    return __virtualname__
+
+
+def nvme_nqn():
+    '''
+    Return NVMe NQN
+    '''
+    grains = {}
+    grains['nvme_nqn'] = False
+    if salt.utils.platform.is_linux():
+        grains['nvme_nqn'] = _linux_nqn()
+    return grains
+
+
+def _linux_nqn():
+    '''
+    Return NVMe NQN from a Linux host.
+    '''
+    ret = []
+
+    initiator = '/etc/nvme/hostnqn'
+    try:
+        with salt.utils.files.fopen(initiator, 'r') as _nvme:
+            for line in _nvme:
+                line = line.strip()
+                if line.startswith('nqn.'):
+                    ret.append(line)
+    except IOError as ex:
+        if ex.errno != errno.ENOENT:
+            log.debug("Error while accessing '%s': %s", initiator, ex)
+
+    return ret

tests/unit/grains/test_nvme.py

@@ -0,0 +1,67 @@
+# -*- coding: utf-8 -*-
+'''
+    :codeauthor: :email:`Simon Dodsley <simon@purestorage.com>`
+'''
+# Import Python libs
+from __future__ import absolute_import, print_function, unicode_literals
+import errno
+import textwrap
+
+# Import Salt Testing Libs
+from tests.support.unit import TestCase, skipIf
+from tests.support.mock import (
+    patch,
+    mock_open,
+    MagicMock,
+    NO_MOCK,
+    NO_MOCK_REASON
+)
+
+# Import Salt Libs
+import salt.grains.nvme as nvme
+
+
+@skipIf(NO_MOCK, NO_MOCK_REASON)
+class NvmeGrainsTestCase(TestCase):
+    '''
+    Test cases for nvme grains
+    '''
+
+    def test_linux_nvme_nqn_grains(self):
+        _nvme_file = textwrap.dedent('''\
+            nqn.2014-08.org.nvmexpress:fc_lif:uuid:2cd61a74-17f9-4c22-b350-3020020c458d
+            ''')
+
+        with patch('salt.utils.files.fopen', mock_open(read_data=_nvme_file)):
+            nqn = nvme._linux_nqn()
+
+        assert isinstance(nqn, list)
+        assert len(nqn) == 1
+        assert nqn == ['nqn.2014-08.org.nvmexpress:fc_lif:uuid:2cd61a74-17f9-4c22-b350-3020020c458d']
+
+    @patch('salt.utils.files.fopen', MagicMock(side_effect=IOError(errno.EPERM,
+                                                                   'The cables are not the same length.')))
+    @patch('salt.grains.nvme.log', MagicMock())
+    def test_linux_nqn_non_root(self):
+        '''
+        Test if linux_nqn is running on salt-master as non-root
+        and handling access denial properly.
+        :return:
+        '''
+        assert nvme._linux_nqn() == []
+        nvme.log.debug.assert_called()
+        assert 'Error while accessing' in nvme.log.debug.call_args[0][0]
+        assert 'cables are not the same' in nvme.log.debug.call_args[0][2].strerror
+        assert nvme.log.debug.call_args[0][2].errno == errno.EPERM
+        assert nvme.log.debug.call_args[0][1] == '/etc/nvme/hostnqn'
+
+    @patch('salt.utils.files.fopen', MagicMock(side_effect=IOError(errno.ENOENT, '')))
+    @patch('salt.grains.nvme.log', MagicMock())
+    def test_linux_nqn_no_nvme_initiator(self):
+        '''
+        Test if linux_nqn is running on salt-master as root.
+        nvme initiator is not there accessible or is not supported.
+        :return:
+        '''
+        assert nvme._linux_nqn() == []
+        nvme.log.debug.assert_not_called()