diff --git a/node-daemon/plugins/zkpr b/node-daemon/plugins/zkpr new file mode 100644 index 00000000..6cf3ee53 --- /dev/null +++ b/node-daemon/plugins/zkpr @@ -0,0 +1,107 @@ +#!/usr/bin/env python3 + +# zkpr.py - PVC Monitoring example plugin for Zookeeper +# Part of the Parallel Virtual Cluster (PVC) system +# +# Copyright (C) 2018-2022 Joshua M. Boniface +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, version 3. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . +# +############################################################################### + +# This script provides an example of a PVC monitoring plugin script. It will create +# a simple plugin to check the Zookeeper instance on the node for operation. + +# This script can thus be used as an example or reference implementation of a +# PVC monitoring pluginscript and expanded upon as required. + +# A monitoring plugin script must implement the class "MonitoringPluginScript" which +# extends "MonitoringPlugin", providing the 3 functions indicated. Detailed explanation +# of the role of each function is provided in context of the example; see the other +# examples for more potential uses. + +# WARNING: +# +# This script will run in the context of the node daemon keepalives as root. +# DO NOT install untrusted, unvetted plugins under any circumstances. + + +# This import is always required here, as MonitoringPlugin is used by the +# MonitoringPluginScript class +from pvcnoded.objects.MonitoringInstance import MonitoringPlugin + + +# A monitoring plugin script must always expose its nice name, which must be identical to +# the file name +PLUGIN_NAME = "zkpr" + + +# The MonitoringPluginScript class must be named as such, and extend MonitoringPlugin. +class MonitoringPluginScript(MonitoringPlugin): + def setup(self): + """ + setup(): Perform special setup steps during node daemon startup + + This step is optional and should be used sparingly. + + If you wish for the plugin to not zkpr in certain conditions, do any checks here + and return a non-None failure message to indicate the error. + """ + + pass + + def run(self): + """ + run(): Perform the check actions and return a PluginResult object + """ + + # Run any imports first + from kazoo.client import KazooClient, KazooState + + zk_conn = None + + # Set the health delta to 0 (no change) + health_delta = 0 + # Craft a message that can be used by the clients + message = "Successfully connected to Zookeeper on localhost" + + # Check the Zookeeper connection + try: + zk_conn = KazooClient(hosts=[f"{self.this_node.name}:2181"], timeout=1, read_only=True) + zk_conn.start(timeout=1) + data = zk_conn.get('/primary_node') + except Exception as e: + health_delta = 50 + message = f"Failed to connect to Zookeeper: {e}" + finally: + if zk_conn is not None: + zk_conn.stop() + zk_conn.close() + + # Set the health delta in our local PluginResult object + self.plugin_result.set_health_delta(health_delta) + + # Set the message in our local PluginResult object + self.plugin_result.set_message(message) + + # Return our local PluginResult object + return self.plugin_result + + def cleanup(self): + """ + cleanup(): Perform special cleanup steps during node daemon termination + + This step is optional and should be used sparingly. + """ + + pass