#!/usr/bin/env python3

# ceph.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"


# 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 load 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 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(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