Register opensearch-knn as a plugin

config.yaml

@@ -0,0 +1,8 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+options:
+  plugin_opensearch_knn:
+    default: false
+    type: boolean
+    description: Enable opensearch-knn

lib/charms/opensearch/v0/opensearch_ml_plugins.py

@@ -0,0 +1,65 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""Implements the KNN and ML-Commons plugins for OpenSearch."""
+
+import logging
+from typing import Any, Dict
+
+from charms.opensearch.v0.opensearch_plugins import OpenSearchPlugin
+
+logger = logging.getLogger(__name__)
+
+
+# The unique Charmhub library identifier, never change it
+LIBID = "71166db20ab244099ae966c8055db2df"
+
+# Increment this major API version when introducing breaking changes
+LIBAPI = 0
+
+# Increment this PATCH version before using `charmcraft publish-lib` or reset
+# to 0 if you are raising the major API version
+LIBPATCH = 1
+
+
+class OpenSearchKnn(OpenSearchPlugin):
+    """Implements the opensearch-knn plugin."""
+
+    def __init__(
+        self,
+        plugins_path: str,
+    ):
+        super().__init__(plugins_path)
+
+    def config(self) -> Dict[str, Dict[str, str]]:
+        """Returns a dict containing all the configuration needed to be applied in the form.
+
+        Format:
+        {
+            "opensearch.yml": {...},
+            "keystore": {...},
+        }
+        """
+        return {self.CONFIG_YML: {"knn.plugin.enabled": "true"}, "keystore": {}}
+
+    def _is_enabled(self, opensearch_config: Dict[str, Any]) -> None:
+        self._enabled = opensearch_config.get("knn.plugin.enabled", "false") == "true"
+
+    def disable(self) -> Dict[str, Any]:
+        """Returns a dict containing different config changes.
+
+        The dict should return:
+        (1) all the configs to remove
+        (2) all the configs to add
+        (3) all the keystore values to be remmoved.
+        """
+        return {
+            "to_remove_opensearch": ["knn.plugin.enabled"],
+            "to_add_opensearch": [],
+            "to_remove_keystore": [],
+        }
+
+    @property
+    def name(self) -> str:
+        """Returns the name of the plugin."""
+        return "opensearch-knn"

lib/charms/opensearch/v0/opensearch_plugin_manager.py

@@ -14,6 +14,7 @@
 from typing import List
 
 from charms.opensearch.v0.opensearch_exceptions import OpenSearchCmdError
+from charms.opensearch.v0.opensearch_ml_plugins import OpenSearchKnn
 from charms.opensearch.v0.opensearch_plugins import (
     OpenSearchPlugin,
     OpenSearchPluginError,
@@ -34,7 +35,13 @@
 logger = logging.getLogger(__name__)
 
 
-ConfigExposedPlugins = {}
+ConfigExposedPlugins = {
+    "opensearch-knn": {
+        "class": OpenSearchKnn,
+        "config-name": "plugin_opensearch_knn",
+        "relation-name": None,
+    }
+}
 
 
 class OpenSearchPluginManager:

tests/unit/lib/test_ml_plugins.py

@@ -0,0 +1,89 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""Unit test for the opensearch_plugins library."""
+import unittest
+from unittest.mock import MagicMock, PropertyMock, call, patch
+
+import charms
+from charms.opensearch.v0.opensearch_ml_plugins import OpenSearchKnn
+from charms.rolling_ops.v0.rollingops import RollingOpsManager
+from ops.testing import Harness
+
+from charm import OpenSearchOperatorCharm
+
+RETURN_LIST_PLUGINS = """opensearch-alerting
+opensearch-anomaly-detection
+opensearch-asynchronous-search
+opensearch-cross-cluster-replication
+opensearch-geospatial
+opensearch-index-management
+opensearch-job-scheduler
+opensearch-knn
+opensearch-ml
+opensearch-notifications
+opensearch-notifications-core
+opensearch-observability
+opensearch-performance-analyzer
+opensearch-reports-scheduler
+opensearch-security
+opensearch-sql
+"""
+
+
+class TestOpenSearchKNN(unittest.TestCase):
+    def setUp(self) -> None:
+        self.harness = Harness(OpenSearchOperatorCharm)
+        self.addCleanup(self.harness.cleanup)
+        self.harness.begin()
+        self.charm = self.harness.charm
+        self.charm.opensearch.paths.plugins = "tests/unit/resources"
+        self.plugin_manager = self.charm.plugin_manager
+        self.plugin_manager._plugins_path = self.charm.opensearch.paths.plugins
+        # Override the ConfigExposedPlugins and ensure one single plugin exists
+        charms.opensearch.v0.opensearch_plugin_manager.ConfigExposedPlugins = {
+            "opensearch-knn": {
+                "class": OpenSearchKnn,
+                "config-name": "plugin_opensearch_knn",
+                "relation-name": None,
+            }
+        }
+
+    @patch.object(RollingOpsManager, "_on_acquire_lock")
+    @patch(
+        "charms.opensearch.v0.opensearch_distro.OpenSearchDistribution.version",
+        new_callable=PropertyMock,
+    )
+    @patch("charms.opensearch.v0.opensearch_plugin_manager.OpenSearchPluginManager.is_installed")
+    @patch("charms.opensearch.v0.opensearch_distro.OpenSearchDistribution.is_started")
+    @patch("charms.opensearch.v0.opensearch_config.OpenSearchConfig.load_node")
+    @patch("charms.opensearch.v0.helper_conf_setter.YamlConfigSetter.put")
+    def test_config_changed(
+        self, _, mock_load, mock_is_started, mock_is_installed, mock_version, mock_acquire_lock
+    ) -> None:
+        """Tests config_changed with KNN plugin."""
+        mock_is_installed.return_value = True
+        mock_is_started.return_value = True
+        mock_version.return_value = "2.9.0"
+        self.plugin_manager._keystore.add = MagicMock()
+        self.plugin_manager._add_plugin = MagicMock()
+        self.charm.opensearch.run_bin = MagicMock(return_value=RETURN_LIST_PLUGINS)
+        mock_load.side_effect = [
+            {},
+            {},
+            {},
+            {},
+            {"knn.plugin.enabled": "true"},
+            {"knn.plugin.enabled": "true"},
+            {"knn.plugin.enabled": "true"},
+            {"knn.plugin.enabled": "true"},
+            {"knn.plugin.enabled": "true"},
+        ]
+
+        self.harness.update_config({"plugin_opensearch_knn": True})
+        self.charm.opensearch.config.put.assert_has_calls(
+            [call(self.charm.opensearch_config.CONFIG_YML, "knn.plugin.enabled", "true")]
+        )
+        self.charm.opensearch.run_bin.assert_called_once_with("opensearch-plugin", "list")
+        self.plugin_manager._add_plugin.assert_not_called()
+        mock_acquire_lock.assert_called_once()