Make RacksDB dependency optional

CHANGELOG.md

@@ -15,6 +15,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Configuration guides to setup production HTTP server (apache2, nginx and
     caddy) on SLES.
 
+### Changed
+- agent: Make RacksDB library optional with lazy loading only when enabled in
+  configuration (#683). Contribution from @faganihajizada.
+
 ### Fixed
 - agent: Import of ClusterShell NodeSet class (#682). Contribution from
   @faganihajizada.

slurmweb/apps/agent.py

@@ -9,8 +9,6 @@
 import logging
 
 from rfl.web.tokens import RFLTokenizedRBACWebApp
-from racksdb.errors import RacksDBSchemaError, RacksDBFormatError
-from racksdb.web.app import RacksDBWebBlueprint
 
 try:
     from werkzeug.middleware import dispatcher
@@ -65,6 +63,11 @@ def __init__(self, seed):
         # If enabled, load RacksDB blueprint and fail with error if unable to load
         # schema or database.
         if self.settings.racksdb.enabled:
+            # Lazy load RacksDB module to avoid failing on missing optional external
+            # dependency when feature is actually disabled.
+            from racksdb.errors import RacksDBSchemaError, RacksDBFormatError
+            from racksdb.web.app import RacksDBWebBlueprint
+
             try:
                 self.register_blueprint(
                     RacksDBWebBlueprint(

slurmweb/tests/apps/test_agent.py

@@ -5,11 +5,12 @@
 # SPDX-License-Identifier: MIT
 
 import sys
+import unittest
 from unittest import mock
 
 from slurmweb.errors import SlurmwebConfigurationError
 
-from ..lib.agent import TestAgentBase
+from ..lib.agent import TestAgentBase, is_racksdb_available
 
 
 class TestAgentApp(TestAgentBase):
@@ -22,6 +23,7 @@ def test_app_loaded(self):
             with self.assertNoLogs("slurmweb", level="ERROR"):
                 self.setup_client()
 
+    @unittest.skipIf(not is_racksdb_available(), "RacksDB not installed")
     def test_app_racksdb_format_error(self):
         with self.assertLogs("slurmweb", level="ERROR") as cm:
             self.setup_client(racksdb_format_error=True)
@@ -33,6 +35,7 @@ def test_app_racksdb_format_error(self):
             ],
         )
 
+    @unittest.skipIf(not is_racksdb_available(), "RacksDB not installed")
     def test_app_racksdb_schema_error(self):
         with self.assertLogs("slurmweb", level="ERROR") as cm:
             self.setup_client(racksdb_schema_error=True)

slurmweb/tests/lib/agent.py

@@ -8,7 +8,7 @@
 from unittest import mock
 import tempfile
 import os
-
+from importlib.util import find_spec
 
 import werkzeug
 from flask import Blueprint, jsonify
@@ -18,7 +18,6 @@
 from rfl.permissions.rbac import ANONYMOUS_ROLE
 from slurmweb.apps import SlurmwebAppSeed
 from slurmweb.apps.agent import SlurmwebAppAgent
-from racksdb.errors import RacksDBFormatError, RacksDBSchemaError
 
 from .utils import (
     mock_slurmrestd_responses,
@@ -27,6 +26,11 @@
 )
 
 
+def is_racksdb_available():
+    """Check if RacksDB is available for testing."""
+    return find_spec("racksdb") is not None
+
+
 CONF_TPL = """
 [service]
 cluster=test
@@ -147,21 +151,41 @@ def setup_client(
         anonymous_enabled=True,
         use_token=True,
     ):
+        # Check if RacksDB is available for mocking
+        try:
+            from racksdb.errors import RacksDBFormatError, RacksDBSchemaError
+        except ModuleNotFoundError:
+            # RacksDB not available, disable it in config
+            racksdb = False
+
         self.setup_agent_conf(
             slurmrestd_parameters=slurmrestd_parameters,
             racksdb=racksdb,
             metrics=metrics,
             cache=cache,
         )
 
-        # Start the app with mocked RacksDB web blueprint
-        with mock.patch("slurmweb.apps.agent.RacksDBWebBlueprint") as m:
-            if racksdb_format_error:
-                m.side_effect = RacksDBFormatError("fake db format error")
-            elif racksdb_schema_error:
-                m.side_effect = RacksDBSchemaError("fake db schema error")
-            else:
-                m.return_value = FakeRacksDBWebBlueprint()
+        if racksdb:
+            # RacksDB is available, start app with mocked RacksDB web blueprint
+            with mock.patch("racksdb.web.app.RacksDBWebBlueprint") as m:
+                if racksdb_format_error:
+                    m.side_effect = RacksDBFormatError("fake db format error")
+                elif racksdb_schema_error:
+                    m.side_effect = RacksDBSchemaError("fake db schema error")
+                else:
+                    m.return_value = FakeRacksDBWebBlueprint()
+                self.app = SlurmwebAppAgent(
+                    SlurmwebAppSeed.with_parameters(
+                        debug=False,
+                        log_flags=["ALL"],
+                        log_component=None,
+                        debug_flags=[],
+                        conf_defs=self.conf_defs,
+                        conf=self.conf.name,
+                    )
+                )
+        else:
+            # RacksDB disabled in config or not available
             self.app = SlurmwebAppAgent(
                 SlurmwebAppSeed.with_parameters(
                     debug=False,
@@ -172,6 +196,7 @@ def setup_client(
                     conf=self.conf.name,
                 )
             )
+
         if not anonymous_enabled:
             self.app.policy.disable_anonymous()
 

slurmweb/tests/lib/gateway.py

@@ -14,14 +14,16 @@
 import jinja2
 
 from rfl.authentication.user import AuthenticatedUser, AnonymousUser
-from racksdb.version import get_version as racksdb_get_version
+
 from slurmweb.version import get_version
 from slurmweb.apps import SlurmwebAppSeed
 from slurmweb.apps.gateway import SlurmwebAppGateway
 from slurmweb.apps.gateway import SlurmwebAgent, SlurmwebAgentRacksDBSettings
+from slurmweb.views.agent import racksdb_get_version
 
 from .utils import SlurmwebCustomTestResponse
 
+
 CONF_TPL = """
 [agents]
 url=http://localhost

slurmweb/tests/views/test_agent.py

@@ -10,14 +10,13 @@
 
 from ClusterShell.NodeSet import NodeSet
 
-from racksdb.version import get_version as racksdb_get_version
-
 from slurmweb.version import get_version
 from slurmweb.slurmrestd.errors import (
     SlurmrestConnectionError,
     SlurmrestdInvalidResponseError,
 )
 from slurmweb.cache import CachingService
+from slurmweb.views.agent import racksdb_get_version
 
 from ..lib.agent import TestAgentBase
 from ..lib.utils import all_slurm_api_versions, flask_404_description

slurmweb/tests/views/test_agent_racksdb.py

@@ -4,11 +4,13 @@
 #
 # SPDX-License-Identifier: MIT
 
+import unittest
 
-from ..lib.agent import TestAgentBase
+from ..lib.agent import TestAgentBase, is_racksdb_available
 from ..lib.utils import flask_404_description
 
 
+@unittest.skipIf(not is_racksdb_available(), "RacksDB not installed")
 class TestAgentRacksDBEnabledRequest(TestAgentBase):
     def setUp(self):
         self.setup_client()
@@ -23,6 +25,7 @@ def test_request_racksdb(self):
         )
 
 
+@unittest.skipIf(not is_racksdb_available(), "RacksDB not installed")
 class TestAgentRacksDBUnabledRequest(TestAgentBase):
     def setUp(self):
         self.setup_client(racksdb_format_error=True)

slurmweb/views/agent.py

@@ -9,7 +9,6 @@
 
 from flask import Response, current_app, jsonify, abort, request
 from rfl.web.tokens import rbac_action, check_jwt
-from racksdb.version import get_version as racksdb_get_version
 
 from ..version import get_version
 from ..errors import SlurmwebCacheError, SlurmwebMetricsDBError
@@ -26,6 +25,16 @@
 logger = logging.getLogger(__name__)
 
 
+def racksdb_get_version():
+    """Get RacksDB version if available, or return 'N/A' if not installed."""
+    try:
+        from racksdb.version import get_version
+
+        return get_version()
+    except ModuleNotFoundError:
+        return "N/A (not installed)"
+
+
 def version():
     return Response(f"Slurm-web agent v{get_version()}\n", mimetype="text/plain")