Add AzPostgresLogDisconnectionsEvent event plugin

Added AzPostgresLogDisconnectionsEvent event plugin. This plugin evaluates Azure Postgres instances and generates an event of type `postgres_log_disconnections_event` if the `log_disconnections` setting is disabled. Enabling `log_disconnections` helps PostgreSQL Database to log end of session including duration. These logs can be used for troubleshooting and query optimization.
cloudmarker · Feb 29, 2020 · c1aefc7 · c1aefc7
1 parent 2aa806f
commit c1aefc7
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diff --git a/cloudmarker/baseconfig.py b/cloudmarker/baseconfig.py
@@ -77,6 +77,9 @@
   azpostgreslogconnectionsevent:
     plugin: cloudmarker.events.azpostgreslogconnectionsevent.AzPostgresLogConnectionsEvent
 
+  azpostgreslogdisconnectionsevent:
+    plugin: cloudmarker.events.azpostgreslogdisconnectionsevent.AzPostgresLogDisconnectionsEvent
+
   mockevent:
     plugin: cloudmarker.events.mockevent.MockEvent
 

diff --git a/cloudmarker/events/azpostgreslogdisconnectionsevent.py b/cloudmarker/events/azpostgreslogdisconnectionsevent.py
@@ -0,0 +1,106 @@
+"""Microsoft Azure Postgres Log Disconnections event.
+
+This module defines the :class:`AzPostgresLogDisconnectionsEvent` class
+that identifies Postgre SQL servers which log disconnections configuration
+disabled. This plugin works on the  properties found in the ``com``
+bucket of ``postgresql_server`` records.
+"""
+
+
+import logging
+
+from cloudmarker import util
+
+_log = logging.getLogger(__name__)
+
+
+class AzPostgresLogDisconnectionsEvent:
+    """Az Postgres log disconnections event plugin."""
+
+    def __init__(self):
+        """Create an instance of :class:`AzPostgresLogDisconnectionsEvent`."""
+
+    def eval(self, record):
+        """Evaluate Postgres for log disconnections.
+
+        Arguments:
+            record (dict): An RDBMS record.
+
+        Yields:
+            dict: An event record representing a Postgres where
+            log disconnections is disabled
+
+        """
+        com = record.get('com', {})
+        if com is None:
+            return
+
+        if com.get('cloud_type') != 'azure':
+            return
+
+        if com.get('record_type') != 'rdbms':
+            return
+
+        ext = record.get('ext', {})
+        if ext is None:
+            return
+
+        if ext.get('record_type') != 'postgresql_server':
+            return
+
+        # True, None, missing key or any other value will not
+        # genarated an event. An event will be generated only if
+        # the value of `postgresql_server` is False.
+        if ext.get('log_disconnections_enabled') is False:
+            yield from _get_postgres_log_disconnections_disabled_event(
+                com, ext)
+
+    def done(self):
+        """Perform cleanup work.
+
+        Currently, this method does nothing. This may change in future.
+        """
+
+
+def _get_postgres_log_disconnections_disabled_event(com, ext):
+    """Generate event for Postgres log disconnections disabled.
+
+    Arguments:
+        com (dict): Postgres record `com` bucket
+        ext (dict): Postgres record `ext` bucket
+    Returns:
+        dict: An event record representing Postgres server
+        with log disconnections disabled
+
+    """
+    friendly_cloud_type = util.friendly_string(com.get('cloud_type'))
+    friendly_rdbms_type = util.friendly_string(ext.get('record_type'))
+
+    reference = com.get('reference')
+    description = (
+        '{} {} {} has log disconnections disabled.'
+        .format(friendly_cloud_type, friendly_rdbms_type, reference)
+    )
+    recommendation = (
+        'Check {} {} {} and enable log disconnections.'
+        .format(friendly_cloud_type, friendly_rdbms_type, reference)
+    )
+
+    event_record = {
+        # Preserve the extended properties from the RDBMS
+        # record because they provide useful context to
+        # locate the RDBMS that led to the event.
+        'ext': util.merge_dicts(ext, {
+            'record_type': 'postgres_log_disconnections_event'
+        }),
+        'com': {
+            'cloud_type': com.get('cloud_type'),
+            'record_type': 'postgres_log_disconnections_event',
+            'reference': reference,
+            'description': description,
+            'recommendation': recommendation,
+        }
+    }
+
+    _log.info('Generating postgres_log_disconnections_event; %r', event_record)
+    yield event_record
diff --git a/cloudmarker/test/test_azpostgreslogdisconnectionsevent.py b/cloudmarker/test/test_azpostgreslogdisconnectionsevent.py
@@ -0,0 +1,86 @@
+"""Tests for AzPostgresLogDisconnectionsEvent plugin."""
+
+
+import copy
+import unittest
+
+from cloudmarker.events import azpostgreslogdisconnectionsevent
+
+base_record = {
+    'com':  {
+        'cloud_type': 'azure',
+        'record_type': 'rdbms',
+    },
+    'ext': {
+        'record_type': 'postgresql_server',
+        'log_disconnections_enabled': False
+    }
+}
+
+
+class AzPostgresLogDisconnectionsEventTest(unittest.TestCase):
+    """Tests for AzPostgresLogDisconnectionsEvent plugin."""
+
+    def test_com_bucket_missing(self):
+        record = copy.deepcopy(base_record)
+        record['com'] = None
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(events, [])
+
+    def test_cloud_non_azure(self):
+        record = copy.deepcopy(base_record)
+        record['com']['cloud_type'] = 'non_azure'
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(events, [])
+
+    def test_record_type_non_rdbms(self):
+        record = copy.deepcopy(base_record)
+        record['com']['record_type'] = 'non_rdbms'
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(events, [])
+
+    def test_ext_bucket_missing(self):
+        record = copy.deepcopy(base_record)
+        record['ext'] = None
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(events, [])
+
+    def test_record_type_non_postgresql_server(self):
+        record = copy.deepcopy(base_record)
+        record['ext']['record_type'] = 'non_postgresql_server'
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(events, [])
+
+    def test_log_disconnections_enabled(self):
+        record = copy.deepcopy(base_record)
+        record['ext']['log_disconnections_enabled'] = True
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(events, [])
+
+    def test_log_disconnections_disabled(self):
+        record = copy.deepcopy(base_record)
+        plugin = azpostgreslogdisconnectionsevent. \
+            AzPostgresLogDisconnectionsEvent()
+        events = list(plugin.eval(record))
+        self.assertEqual(len(events), 1)
+        self.assertEqual(events[0]['ext']['record_type'],
+                         'postgres_log_disconnections_event')
+        self.assertEqual(events[0]['com']['cloud_type'],
+                         'azure')
+        self.assertEqual(events[0]['com']['record_type'],
+                         'postgres_log_disconnections_event')
+        self.assertTrue('reference' in events[0]['com'])
+        self.assertIsNotNone(events[0]['com']['description'])
+        self.assertIsNotNone(events[0]['com']['recommendation'])
diff --git a/docs/api/cloudmarker.events.rst b/docs/api/cloudmarker.events.rst
@@ -81,6 +81,14 @@ cloudmarker.events.azpostgreslogconnectionsevent module
    :undoc-members:
    :show-inheritance:
 
+cloudmarker.events.azpostgreslogdisconnectionsevent module
+----------------------------------------------------------
+
+.. automodule:: cloudmarker.events.azpostgreslogdisconnectionsevent
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
 cloudmarker.events.azsqldatabasetdeevent module
 -----------------------------------------------
 

diff --git a/pylama.ini b/pylama.ini
@@ -206,3 +206,8 @@ ignore = R0201
 ignore = R0201
 
 # R0201 Method could be a function [pylint]
+
+[pylama:cloudmarker/events/azpostgreslogdisconnectionsevent.py]
+ignore = R0201
+
+# R0201 Method could be a function [pylint]