Add an action to provide information about AZ

The 'get-availability-zone' action will get information about an
availability zone that will contain information about the CRUSH
structure. Specifically 'rack' and 'row'.

Closes-Bug: #1911006
Change-Id: I99ebbef5f23d6efe3c848b089c7f2b0d26ad0077

README.md

@@ -240,6 +240,7 @@ is not deployed then see file `actions.yaml`.
 * `add-disk`
 * `blacklist-add-disk`
 * `blacklist-remove-disk`
+* `get-availibility-zone`
 * `list-disks`
 * `osd-in`
 * `osd-out`

actions.yaml

@@ -116,3 +116,18 @@ stop:
     - osds
 security-checklist:
   description: Validate the running configuration against the OpenStack security guides checklist
+get-availability-zone:
+  description: |
+    Obtain information about the availability zone, which will contain information about the CRUSH
+    structure. Specifically 'rack' and 'row'.
+  params:
+    format:
+      type: string
+      default: text
+      enum:
+        - text
+        - json
+      description: Specify output format (text|json).
+    show-all:
+      type: boolean
+      description: Option to view information for all units. Default is 'false'.

actions/get-availability-zone

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

actions/get_availability_zone.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+#
+# Copyright 2021 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 json
+import sys
+
+from tabulate import tabulate
+
+sys.path.append("hooks")
+sys.path.append("lib")
+
+from charms_ceph.utils import get_osd_tree
+from charmhelpers.core import hookenv
+from utils import get_unit_hostname
+
+
+CRUSH_MAP_HIERARCHY = [
+    "root",  # 10
+    "region",  # 9
+    "datacenter",  # 8
+    "room",  # 7
+    "pod",  # 6
+    "pdu",  # 5
+    "row",  # 4
+    "rack",  # 3
+    "chassis",  # 2
+    "host",  # 1
+    "osd",  # 0
+]
+
+
+def _get_human_readable(availability_zones):
+    """Get human readable table format.
+
+    :param availability_zones: information about the availability zone
+    :type availability_zones: Dict[str, Dict[str, str]]
+    :returns: formatted data as table
+    :rtype: str
+    """
+    data = availability_zones.get(
+        "all-units", {get_unit_hostname(): availability_zones["unit"]}
+    )
+    data = [[unit, *crush_map.values()] for unit, crush_map in data.items()]
+    return tabulate(
+        data, tablefmt="grid", headers=["unit", *CRUSH_MAP_HIERARCHY]
+    )
+
+
+def _get_crush_map(crush_location):
+    """Get Crush Map hierarchy from CrushLocation.
+
+    :param crush_location: CrushLocation from function get_osd_tree
+    :type crush_location: charms_ceph.utils.CrushLocation
+    :returns: dictionary contains the Crush Map hierarchy, where
+              the keys are according to the defined types of the
+              Ceph Map Hierarchy
+    :rtype: Dict[str, str]
+    """
+    return {
+        crush_map_type: getattr(crush_location, crush_map_type)
+        for crush_map_type in CRUSH_MAP_HIERARCHY
+        if getattr(crush_location, crush_map_type, None)
+    }
+
+
+def get_availability_zones(show_all=False):
+    """Get information about the availability zones.
+
+    Returns dictionary contains the unit as the current unit and other_units
+    (if the action was executed with the parameter show-all) that provide
+    information about other units.
+
+    :param show_all: define whether the result should contain AZ information
+                     for all units
+    :type show_all: bool
+    :returns: {"unit": <current-unit-AZ>,
+               "all-units": {<unit-hostname>: <unit-AZ>}}
+    :rtype: Dict[str, Dict[str, str]]
+    """
+    results = {"unit": {}, "all-units": {}}
+    osd_tree = get_osd_tree(service="osd-upgrade")
+
+    this_unit_host = get_unit_hostname()
+    for crush_location in osd_tree:
+        crush_map = _get_crush_map(crush_location)
+        if this_unit_host == crush_location.name:
+            results["unit"] = crush_map
+
+        results["all-units"][crush_location.name] = crush_map
+
+    if not show_all:
+        results.pop("all-units")
+
+    return results
+
+
+def format_availability_zones(availability_zones, human_readable=True):
+    """Format availability zones to action output format."""
+    if human_readable:
+        return _get_human_readable(availability_zones)
+
+    return json.dumps(availability_zones)
+
+
+def main():
+    try:
+        show_all = hookenv.action_get("show-all")
+        human_readable = hookenv.action_get("format") == "text"
+        availability_zones = get_availability_zones(show_all)
+        if not availability_zones["unit"]:
+            hookenv.log(
+                "Availability zone information for current unit not found.",
+                hookenv.DEBUG
+            )
+
+        formatted_azs = format_availability_zones(availability_zones,
+                                                  human_readable)
+        hookenv.action_set({"availability-zone": formatted_azs})
+    except Exception as error:
+        hookenv.action_fail("Action failed: {}".format(str(error)))
+
+
+if __name__ == "__main__":
+    main()

hooks/install

@@ -2,7 +2,7 @@
 # Wrapper to deal with newer Ubuntu versions that don't have py2 installed
 # by default.
 
-declare -a DEPS=('apt' 'pip' 'yaml')
+declare -a DEPS=('apt' 'pip' 'yaml' 'tabulate')
 
 check_and_install() {
     pkg="${1}-${2}"

unit_tests/__init__.py

@@ -13,7 +13,11 @@
 # limitations under the License.
 
 import sys
+from unittest.mock import MagicMock
+
 sys.path.append('hooks')
 sys.path.append('lib')
 sys.path.append('actions')
 sys.path.append('unit_tests')
+
+sys.modules["tabulate"] = MagicMock()

unit_tests/test_actions_get_availability_zone.py

@@ -0,0 +1,119 @@
+# Copyright 2021 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 json
+
+from actions import get_availability_zone
+from lib.charms_ceph.utils import CrushLocation
+
+from test_utils import CharmTestCase
+
+
+TABULATE_OUTPUT = """
++-------------+---------+-------------+
+| unit        | root    | region      |
++=============+=========+=============+
+| juju-ceph-0 | default | juju-ceph-0 |
++-------------+---------+-------------+
+| juju-ceph-1 | default | juju-ceph-1 |
++-------------+---------+-------------+
+| juju-ceph-2 | default | juju-ceph-2 |
++-------------+---------+-------------+
+"""
+
+AVAILABILITY_ZONES = {
+    "unit": {"root": "default", "host": "juju-ceph-0"},
+    "all-units": {
+        "juju-ceph-0": {"root": "default", "host": "juju-ceph-0"},
+        "juju-ceph-1": {"root": "default", "host": "juju-ceph-1"},
+        "juju-ceph-2": {"root": "default", "host": "juju-ceph-2"}
+    }
+}
+
+
+class GetAvailabilityZoneActionTests(CharmTestCase):
+    def setUp(self):
+        super(GetAvailabilityZoneActionTests, self).setUp(
+            get_availability_zone,
+            ["get_osd_tree", "get_unit_hostname", "tabulate"]
+        )
+        self.tabulate.return_value = TABULATE_OUTPUT
+        self.get_unit_hostname.return_value = "juju-ceph-0"
+
+    def test_get_human_readable(self):
+        """Test formatting as human readable."""
+        table = get_availability_zone._get_human_readable(AVAILABILITY_ZONES)
+        self.assertTrue(table == TABULATE_OUTPUT)
+
+    def test_get_crush_map(self):
+        """Test get Crush Map hierarchy from CrushLocation."""
+        crush_location = CrushLocation(
+            name="test", identifier="t1", host="test", rack=None, row=None,
+            datacenter=None, chassis=None, root="default")
+        crush_map = get_availability_zone._get_crush_map(crush_location)
+        self.assertDictEqual(crush_map, {"root": "default", "host": "test"})
+
+        crush_location = CrushLocation(
+            name="test", identifier="t1", host="test", rack="AZ",
+            row="customAZ", datacenter=None, chassis=None, root="default")
+        crush_map = get_availability_zone._get_crush_map(crush_location)
+        self.assertDictEqual(crush_map, {"root": "default", "row": "customAZ",
+                                         "rack": "AZ", "host": "test"})
+
+    def test_get_availability_zones(self):
+        """Test function to get information about availability zones."""
+        self.get_unit_hostname.return_value = "test_1"
+        self.get_osd_tree.return_value = [
+            CrushLocation(name="test_1", identifier="t1", host="test_1",
+                          rack="AZ1", row="AZ", datacenter=None,
+                          chassis=None, root="default"),
+            CrushLocation(name="test_2", identifier="t2", host="test_2",
+                          rack="AZ1", row="AZ", datacenter=None,
+                          chassis=None, root="default"),
+            CrushLocation(name="test_3", identifier="t3", host="test_3",
+                          rack="AZ2", row="AZ", datacenter=None,
+                          chassis=None, root="default"),
+            CrushLocation(name="test_4", identifier="t4", host="test_4",
+                          rack="AZ2", row="AZ", datacenter=None,
+                          chassis=None, root="default"),
+        ]
+        results = get_availability_zone.get_availability_zones()
+
+        self.assertDictEqual(results, {
+            "unit": dict(root="default", row="AZ", rack="AZ1", host="test_1")})
+
+        results = get_availability_zone.get_availability_zones(show_all=True)
+        self.assertDictEqual(results, {
+            "unit": dict(root="default", row="AZ", rack="AZ1", host="test_1"),
+            "all-units": {
+                "test_1": dict(root="default", row="AZ", rack="AZ1",
+                               host="test_1"),
+                "test_2": dict(root="default", row="AZ", rack="AZ1",
+                               host="test_2"),
+                "test_3": dict(root="default", row="AZ", rack="AZ2",
+                               host="test_3"),
+                "test_4": dict(root="default", row="AZ", rack="AZ2",
+                               host="test_4"),
+            }})
+
+    def test_format_availability_zones(self):
+        """Test function to formatted availability zones."""
+        # human readable format
+        results_table = get_availability_zone.format_availability_zones(
+            AVAILABILITY_ZONES, True)
+        self.assertEqual(results_table, TABULATE_OUTPUT)
+
+        # json format
+        results_json = get_availability_zone.format_availability_zones(
+            AVAILABILITY_ZONES, False)
+        self.assertDictEqual(json.loads(results_json), AVAILABILITY_ZONES)