Introduce a zfs_support grain

There was some ugly duplicated logic in salt.modules.zfs and
salt.modules.zpool. This got cleaned up and moved inside salt.grain.zfs.

This way the logic gets execute less often and we can simple check for
zfs_support grain in the other locations.

salt/grains/zfs.py

@@ -0,0 +1,117 @@
+# -*- coding: utf-8 -*-
+'''
+ZFS grain provider
+
+:maintainer:    Jorge Schrauwen <sjorge@blackdot.be>
+:maturity:      new
+:depends:       salt.utils, salt.module.cmdmod
+:platform:      illumos,freebsd,linux
+
+.. versionadded:: Oxygen
+
+'''
+from __future__ import absolute_import
+
+# Import python libs
+import logging
+
+# Import salt libs
+import salt.utils.dictupdate
+import salt.utils.path
+import salt.utils.platform
+
+# Solve the Chicken and egg problem where grains need to run before any
+# of the modules are loaded and are generally available for any usage.
+import salt.modules.cmdmod
+
+__virtualname__ = 'zfs'
+__salt__ = {
+    'cmd.run': salt.modules.cmdmod.run,
+    'cmd.run_all': salt.modules.cmdmod.run_all,
+}
+
+log = logging.getLogger(__name__)
+
+
+def __virtual__():
+    '''
+    Load zfs grains
+    '''
+    # NOTE: we always load this grain so we can properly export
+    #       atleast the zfs_support grain
+    return __virtualname__
+
+
+def _check_retcode(cmd):
+    '''
+    Simple internal wrapper for cmdmod.retcode
+    '''
+    return salt.modules.cmdmod.retcode(cmd, output_loglevel='quiet', ignore_retcode=True) == 0
+
+
+def _zfs_support():
+    '''
+    Provide information about zfs kernel module
+    '''
+    grains = {'zfs_support': False}
+
+    # Check for zfs support
+    # NOTE: ZFS on Windows is in development
+    # NOTE: ZFS on NetBSD is in development
+    on_supported_platform = False
+    if salt.utils.platform.is_sunos():
+        if salt.utils.path.which('zfs'):
+            on_supported_platform = True
+    elif salt.utils.platform.is_freebsd():
+        on_supported_platform = _check_retcode('kldstat -q -m zfs')
+    elif salt.utils.platform.is_linux():
+        modinfo = salt.utils.path.which('modinfo')
+        if modinfo:
+            on_supported_platform = _check_retcode('{0} zfs'.format(modinfo))
+        else:
+            on_supported_platform = _check_retcode('ls /sys/module/zfs')
+
+        # NOTE: fallback to zfs-fuse if needed
+        if not on_supported_platform:
+            _zfs_fuse = lambda f: __salt__['service.' + f]('zfs-fuse')
+            if _zfs_fuse('available') and (_zfs_fuse('status') or _zfs_fuse('start')):
+                on_supported_platform = True
+
+    # Additional check for the zpool command
+    if on_supported_platform and salt.utils.path.which('zpool'):
+        grains['zfs_support'] = True
+
+    return grains
+
+
+def _zfs_pool_data():
+    '''
+    Provide grains about zpools
+    '''
+    grains = {}
+
+    # collect zpool data
+    zpool_cmd = salt.utils.path.which('zpool')
+    for zpool in __salt__['cmd.run']('{zpool} list -H -o name,size'.format(zpool=zpool_cmd)).splitlines():
+        if 'zpool' not in grains:
+            grains['zpool'] = {}
+        zpool = zpool.split()
+        grains['zpool'][zpool[0]] = zpool[1]
+
+    # return grain data
+    return grains
+
+
+def zfs():
+    '''
+    Provide grains for zfs/zpool
+    '''
+    grains = {}
+
+    grains = salt.utils.dictupdate.update(grains, _zfs_support(), merge_lists=True)
+    if grains['zfs_support']:
+        grains = salt.utils.dictupdate.update(grains, _zfs_pool_data(), merge_lists=True)
+
+    return grains
+
+# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4

salt/grains/zpool.py

@@ -1,80 +0,0 @@
-# -*- coding: utf-8 -*-
-'''
-ZFS grain provider
-
-:maintainer:    Jorge Schrauwen <sjorge@blackdot.be>
-:maturity:      new
-:depends:       salt.utils, salt.module.cmdmod
-:platform:      illumos,freebsd,linux
-
-.. versionadded:: Oxygen
-
-'''
-from __future__ import absolute_import
-
-# Import python libs
-import logging
-
-# Import salt libs
-import salt.utils.dictupdate
-import salt.utils.path
-import salt.utils.platform
-
-# Solve the Chicken and egg problem where grains need to run before any
-# of the modules are loaded and are generally available for any usage.
-import salt.modules.cmdmod
-
-__virtualname__ = 'zfs'
-__salt__ = {
-    'cmd.run': salt.modules.cmdmod.run,
-    'cmd.run_all': salt.modules.cmdmod.run_all,
-}
-
-log = logging.getLogger(__name__)
-
-
-def __virtual__():
-    '''
-    Figure out if we need to be loaded
-    '''
-    # Don't load on windows, NetBSD, or proxy
-    # NOTE: ZFS on Windows is in development
-    # NOTE: ZFS on NetBSD is in development
-    if salt.utils.platform.is_windows() or salt.utils.platform.is_netbsd() or 'proxyminion' in __opts__:
-        return False
-
-    # Don't load if we do not have the zpool command
-    if not salt.utils.path.which('zpool'):
-        return False
-
-    return True
-
-
-def _zpool_data(zpool_cmd):
-    '''
-    Provide grains about zpools
-    '''
-    # collect zpool data
-    grains = {}
-    for zpool in __salt__['cmd.run']('{zpool} list -H -o name,size'.format(zpool=zpool_cmd)).splitlines():
-        if 'zpool' not in grains:
-            grains['zpool'] = {}
-        zpool = zpool.split()
-        grains['zpool'][zpool[0]] = zpool[1]
-
-    # return grain data
-    return grains
-
-
-def zpool():
-    '''
-    Provide grains for zfs/zpool
-    '''
-    grains = {}
-    zpool_cmd = salt.utils.path.which('zpool')
-
-    grains = salt.utils.dictupdate.update(grains, _zpool_data(zpool_cmd), merge_lists=True)
-
-    return grains
-
-# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4