Munin contributed plugins

#!/usr/bin/env python3

"""

  rethinkdb_node_io - A munin plugin for Linux to monitor the io count

  per second on the local node

  This plugin is licensed under the AGPL 3.0 license

  AGPL 3.0 RubenKelevra

  Author: @RubenKelevra - <ruben@vfn-nrw.de>

  This plugin is written with the known limitation to a single instance per

  host. Patches which remove this limitation are very welcome.

  If your port / host is somewhat else than the default

  localhost:28015, and/or your database-server differes in name from

  `hostname` (short hostname), you can add rethinkdb-node-io config vars

  like:

	  [rethinkdb_*]

	  env.rethinkdb_port 12345

	  env.rethinkdb_host localhost.com

	  env.rethinkdb_servername localhost.com

  The following munin configuration parameters are supported:

  #%# family=auto contrib

  #%# capabilities=autoconf

"""

from importlib.util import find_spec

from multiprocessing import Process

from os import environ as env

from shutil import which

from socket import gethostname

from sys import argv

from sys import exit as fatal_

from sys import stderr

# functions

def fatal(status):

    fatal_("ERROR: " + status)

def rclose_async():

    conn.close()

def check_load_rethinkdb() -> bool:

    try:

        rdb_spec = find_spec("rethinkdb")

        if rdb_spec is None:

            return False

        return True

    except:

        fatal("Unknown error while try to load RethinkDB-Driver")

def eprint(*args, **kwargs):

    print(*args, file=stderr, **kwargs)

def getFirstLine(respond):

    assert isinstance(respond, net.DefaultCursor)

    for e in respond:

        return e

def print_config(servername):

    print("graph_title RethinkDB on '%s'- Local Database IOPS and Queries" % servername)

    print("graph_args --base 1000 -l 0")

    print("graph_vlabel Operations / second")

    print("graph_category rethinkdb")

    print("total_qps.label queries per sec")

    print("total_qps.type COUNTER")

    print("total_rdps.label read docs per sec")

    print("total_rdps.type COUNTER")

    print("total_wdps.label written docs per sec")

    print("total_wdps.type COUNTER")

    exit(0)

def check_autoconf() -> bool:

    # this might be too easy, but gonna try.

    if which("rethinkdb"):

        return True

    return False

if __name__ == '__main__':

    try:

        RETHINKDB_SERVERNAME = env['rethinkdb_servername']

    except:

        RETHINKDB_SERVERNAME = gethostname()

    if len(argv) > 2:

        fatal("unsupported argument count")

    elif len(argv) == 2:

        if str(argv[1]) == "config":

            print_config(RETHINKDB_SERVERNAME)

        elif str(argv[1]) == "autoconf":

            if check_autoconf():

                print("yes")

            else:

                print("no")

            if not check_load_rethinkdb():

                # FIXME: Correct display of error message when driver is missing should be checked

                fatal("RethinkDB-Driver not available!")

            exit(0)

        else:

            fatal("unsupported argument")

    if not check_load_rethinkdb():

        fatal("RethinkDB-Driver not available!")

    from rethinkdb import net, connect, db

    # load environment

    try:

        RETHINKDB_PORT = env['rethinkdb_port']

    except:

        RETHINKDB_PORT = "28015"

    try:

        RETHINKDB_HOST = env['rethinkdb_host']

    except:

        RETHINKDB_HOST = "localhost"

    try:

        conn = connect(RETHINKDB_HOST, RETHINKDB_PORT)

    except:

        fatal("connection attempt to the rethinkdb-host \"%s\" via port \"%s\" failed" % (

            str(RETHINKDB_HOST), str(RETHINKDB_PORT)))

    query_engine_info = getFirstLine(

        db('rethinkdb').table("stats").filter({"server": RETHINKDB_SERVERNAME}).pluck('query_engine').limit(1).run(

            conn))['query_engine']

    rclose = Process(target=rclose_async())

    rclose.start()

    print("total_qps.value %s" % (query_engine_info["queries_total"]))

    print("total_rdps.value %s" % (query_engine_info["read_docs_total"]))

    print("total_wdps.value %s" % (query_engine_info["written_docs_total"]))

    # wait for connection termination

    rclose.join()