Add action to support nfs share ghosting.

src/actions.yaml

@@ -0,0 +1,8 @@
+ghost-share:
+  description: "Bind mount NFS share 'host' for secondary Trilio Vault deployment"
+  properties:
+    nfs-shares:
+      type: string
+      description: Exact nfs-shares configuration option from secondary deployment
+  required:
+    - nfs-shares

src/actions/actions.py

@@ -0,0 +1,64 @@
+#!/usr/local/sbin/charm-env python3
+# Copyright 2018,2020 Canonical Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import sys
+
+# Load modules from $CHARM_DIR/lib
+sys.path.append("lib")
+
+from charms.layer import basic
+
+basic.bootstrap_charm_deps()
+basic.init_config_states()
+
+import charmhelpers.core.hookenv as hookenv
+
+import charms_openstack.charm
+
+# import the trilio_wlm module to get the charm definitions created.
+import charm.openstack.trilio_dm  # noqa
+
+
+def ghost_share(*args):
+    """Ghost mount secondard TV deployment nfs-share
+    """
+    secondary_nfs_share = hookenv.function_get("nfs-shares")
+    with charms_openstack.charm.provide_charm_instance() as trilio_wlm_charm:
+        trilio_wlm_charm.ghost_nfs_share(secondary_nfs_share)
+
+
+# Actions to function mapping, to allow for illegal python action names that
+# can map to a python function.
+ACTIONS = {
+    "ghost-share": ghost_share,
+}
+
+
+def main(args):
+    action_name = os.path.basename(args[0])
+    try:
+        action = ACTIONS[action_name]
+    except KeyError:
+        return "Action %s undefined" % action_name
+    else:
+        try:
+            action(args)
+        except Exception as e:
+            hookenv.function_fail(str(e))
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))

src/actions/ghost-share

@@ -0,0 +1 @@
+actions.py

src/lib/charm/openstack/trilio_dm.py

@@ -14,8 +14,10 @@
 
 import base64
 import collections
+import os
 
 import charmhelpers.core.hookenv as hookenv
+import charmhelpers.core.host as host
 import charmhelpers.fetch as fetch
 
 import charms_openstack.charm
@@ -23,6 +25,19 @@ import charms_openstack.adapters as os_adapters
 
 
 VALID_BACKUP_TARGETS = ["nfs"]
+TV_MOUNTS = "/var/triliovault-mounts"
+
+
+class NFSShareNotMountedException(Exception):
+    """Signal that the trilio nfs share is not mount"""
+
+    pass
+
+
+class GhostShareAlreadyMountedException(Exception):
+    """Signal that a ghost share is already mounted"""
+
+    pass
 
 
 class TrilioDataMoverCharm(charms_openstack.charm.OpenStackCharm):
@@ -77,10 +92,45 @@ class TrilioDataMoverCharm(charms_openstack.charm.OpenStackCharm):
     def restart_map(self):
         return {self.data_mover_conf: self.services}
 
+    def install(self):
+        self.configure_source()
+        super().install()
+
     def _encode_endpoint(self, backup_endpoint):
         """base64 encode an backup endpoint for cross mounting support"""
         return base64.b64encode(backup_endpoint.encode()).decode()
 
-    def install(self):
-        self.configure_source()
-        super().install()
+    # TODO: refactor into a layer/module
+    def ghost_nfs_share(self, ghost_share):
+        """Bind mount the local units nfs share to another sites location
+
+        :param ghost_share: NFS share URL to ghost
+        :type ghost_share: str
+        """
+        nfs_share_path = os.path.join(
+            TV_MOUNTS, self._encode_endpoint(hookenv.config("nfs-shares"))
+        )
+        ghost_share_path = os.path.join(
+            TV_MOUNTS, self._encode_endpoint(ghost_share)
+        )
+
+        current_mounts = [mount[0] for mount in host.mounts()]
+
+        if nfs_share_path not in current_mounts:
+            # Trilio has not mounted the NFS share so return
+            raise NFSShareNotMountedException(
+                "nfs-shares ({}) not mounted".format(
+                    hookenv.config("nfs-shares")
+                )
+            )
+
+        if ghost_share_path in current_mounts:
+            # bind mount already setup so return
+            raise GhostShareAlreadyMountedException(
+                "ghost mountpoint ({}) already bound".format(ghost_share_path)
+            )
+
+        if not os.path.exists(ghost_share_path):
+            os.mkdir(ghost_share_path)
+
+        host.mount(nfs_share_path, ghost_share_path, options="bind")

tox.ini

@@ -50,6 +50,11 @@ basepython = python3.7
 deps = -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
 
+[testenv:py38]
+basepython = python3.8
+deps = -r{toxinidir}/test-requirements.txt
+commands = stestr run --slowest {posargs}
+
 [testenv:pep8]
 basepython = python3
 deps = -r{toxinidir}/test-requirements.txt

unit_tests/test_lib_charm_openstack_trilio_dm.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
 
 import charm.openstack.trilio_dm as trilio_dm
 import charms_openstack.test_utils as test_utils
@@ -51,3 +52,61 @@ class TestTrilioDataMoverCharms(Helper):
         self.assertEqual(
             dm_charm.services, ["tvault-contego", "tvault-object-store"]
         )
+
+
+# TODO: refactor into a layer/module
+class TestTrilioDataMoverCharmGhostShareAction(Helper):
+
+    _nfs_shares = "10.20.30.40:/srv/trilioshare"
+    _ghost_shares = "50.20.30.40:/srv/trilioshare"
+
+    def setUp(self):
+        super().setUp()
+        self.patch_object(trilio_dm.hookenv, "config")
+        self.patch_object(trilio_dm.host, "mounts")
+        self.patch_object(trilio_dm.host, "mount")
+        self.patch_object(trilio_dm.os.path, "exists")
+        self.patch_object(trilio_dm.os, "mkdir")
+
+        self.trilio_wlm_charm = trilio_dm.TrilioDataMoverCharm()
+        self._nfs_path = os.path.join(
+            trilio_dm.TV_MOUNTS,
+            self.trilio_wlm_charm._encode_endpoint(self._nfs_shares),
+        )
+        self._ghost_path = os.path.join(
+            trilio_dm.TV_MOUNTS,
+            self.trilio_wlm_charm._encode_endpoint(self._ghost_shares),
+        )
+
+    def test_ghost_share(self):
+        self.config.return_value = self._nfs_shares
+        self.mounts.return_value = [
+            ["/srv/nova", "/dev/sda"],
+            [self._nfs_path, self._nfs_shares],
+        ]
+        self.exists.return_value = False
+        self.trilio_wlm_charm.ghost_nfs_share(self._ghost_shares)
+        self.exists.assert_called_once_with(self._ghost_path)
+        self.mkdir.assert_called_once_with(self._ghost_path)
+        self.mount.assert_called_once_with(
+            self._nfs_path, self._ghost_path, options="bind"
+        )
+
+    def test_ghost_share_already_bound(self):
+        self.config.return_value = self._nfs_shares
+        self.mounts.return_value = [
+            ["/srv/nova", "/dev/sda"],
+            [self._nfs_path, self._nfs_shares],
+            [self._ghost_path, self._nfs_shares],
+        ]
+        with self.assertRaises(trilio_dm.GhostShareAlreadyMountedException):
+            self.trilio_wlm_charm.ghost_nfs_share(self._ghost_shares)
+        self.mount.assert_not_called()
+
+    def test_ghost_share_nfs_unmounted(self):
+        self.config.return_value = self._nfs_shares
+        self.mounts.return_value = [["/srv/nova", "/dev/sda"]]
+        self.exists.return_value = False
+        with self.assertRaises(trilio_dm.NFSShareNotMountedException):
+            self.trilio_wlm_charm.ghost_nfs_share(self._ghost_shares)
+        self.mount.assert_not_called()