#!/usr/bin/env python3

# ceph-cluster.py - PVC Monitoring example plugin for Ceph status
# Part of the Parallel Virtual Cluster (PVC) system
#
#    Copyright (C) 2018-2022 Joshua M. Boniface <joshua@boniface.me>
#
#    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 <https://www.gnu.org/licenses/>.
#
###############################################################################

# This script provides an example of a PVC monitoring plugin script. It will create
# a simple plugin to check the Ceph cluster health for anomalies, and return a health
# delta reflective of the overall Ceph status (HEALTH_WARN = 10, HEALTH_ERR = 50).

# 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 = "ceph-cluster"


# 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.
        """

        pass

    def run(self):
        """
        run(): Perform the check actions and return a PluginResult object
        """

        # Run any imports first
        from rados import Rados
        from json import loads, dumps

        # Connect to the Ceph cluster
        try:
            ceph_conn = Rados(
                conffile=self.config["ceph_config_file"],
                conf=dict(keyring=self.config["ceph_admin_keyring"]),
            )
            ceph_conn.connect(timeout=1)
        except Exception as e:
            self.log(f"Failed to connect to Ceph cluster: {e}", state="e")
            return self.plugin_result
            
        # Get the Ceph cluster health
        try:
            health_status = loads(
                ceph_conn.mon_command(dumps({"prefix": "health", "format": "json"}), b"", timeout=1)[1]
            )
            ceph_health = health_status["status"]
        except Exception as e:
            self.log(f"Failed to get health data from Ceph cluster: {e}", state="e")
            return self.plugin_result
        finally:
            ceph_conn.shutdown()

        # Get a list of error entries in the health status output
        error_entries = health_status["checks"].keys()

        # Set the health delta based on the errors presented
        if ceph_health == "HEALTH_ERR":
            health_delta = 50
            message = f"Ceph cluster in ERROR state: {', '.join(error_entries)}"
        elif ceph_health == "HEALTH_WARN":
            health_delta = 10
            message = f"Ceph cluster in WARNING state: {', '.join(error_entries)}"
        else:
            health_delta = 0
            message = "Ceph cluster in OK state"

        # 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)

        # Set the detailed data in our local PluginResult object
        self.plugin_result.set_data(dumps(health_status))

        # 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