Arborist-SNMP

=============

home

: http://bitbucket.org/mahlon/Arborist-SNMP

code

: http://code.martini.nu/Arborist-SNMP

Description

-----------

Arborist is a monitoring toolkit that follows the UNIX philosophy

of small parts and loose coupling for stability, reliability, and

customizability.

This adds various SNMP support to Arborist's monitoring, specifically

for OIDS involving:

 - Disk space capacity

 - System CPU utilization

 - Memory and swap usage

 - Running process checks

It tries to provide sane defaults, while allowing fine grained settings

per resource node.  Both Windows and UCD-SNMP systems are supported.

Prerequisites

-------------

  * Ruby 2.3 or better

  * Net-SNMP libraries

Installation

------------

    $ gem install arborist-snmp

Configuration

-------------

Global configuration overrides can be added to the Arborist config file,

under the `snmp` key.

The defaults are as follows:

	arborist:

	  snmp:

		timeout: 2

		retries: 1

		community: public

		version: 2c

		port: 161

		batchsize: 25

		cpu:

		  warn_at: 80

		disk:

		  warn_at: 90

		  include: ~

		  exclude:

		  - "^/dev(/.+)?$"

		  - "^/net(/.+)?$"

		  - "^/proc$"

		  - "^/run$"

		  - "^/sys/"

		memory:

		  physical_warn_at: ~

		  swap_warn_at: 60

		processes:

		  check: []

The `warn_at` keys imply usage capacity as a percentage. ie:  "Warn me

when a disk mount point is at 90 percent utilization."

### Library Options

  * **timeout**: How long to wait for an SNMP response, in seconds?

  * **retries**: If an error occurs during SNMP communication, try again this many times before giving up.

  * **community**: The SNMP community name for reading data.

  * **version**: The SNMP protocol version.  1 and 2c are supported.

  * **port**: The UDP port SNMP is listening on.

  * **batchsize**: How many hosts to gather SNMP data on simultaneously.

### Category Options and Behavior

#### CPU

  * **warn_at**: Set the node to a `warning` state when utilization is at or over this percentage.

Utilization takes into account CPU core counts, and uses the 5 minute

load average to calculate a percentage of current CPU use.

2 properties are set on the node. `cpu` contains the detected CPU count

and current utilization. `load` contains the 1, 5, and 15 minute load

averages of the machine.

#### Disk

  * **warn_at**: Set the node to a `warning` state when disk capacity is at or over this amount.

                 You can also set this to a Hash, keyed on mount name, if you want differing

                 warning values per mount point.  A mount point that is at 100% capacity will

                 be explicity set to `down`, as the resource it represents has been exhausted.

  * **include**: String or Array of Strings.  If present, only matching mount points are

                 considered while performing checks.  These are treated as regular expressions.

  * **exclude**: String or Array of Strings.  If present, matching mount point are removed

                 from evaluation.  These are treated as regular expressions.

#### Memory

  * **physical_warn_at**: Set the node to a `warning` state when RAM utilization is at or over this percentage.

  * **swap_warn_at**: Set the node to a `warning` state when swap utilization is at or over this percentage.

Warnings are only set for swap my default, since that is usually a

better indication of an impending problem.

#### Processes

  * **check**: String or Array of Strings.  A list of processes to check if running.  These are

               treated as regular expressions, and include process arguments.

If any process in the list is not found in the process table, the

resource is set to a `down` state.

Examples

--------

In the simplest form, using default behaviors and settings, here's an

example Monitor configuration:

    require 'arborist/snmp'

    Arborist::Monitor 'cpu load check', :cpu do

        every 1.minute

        match type: 'resource', category: 'cpu'

        exec( Arborist::Monitor::SNMP::CPU )

    end

    Arborist::Monitor 'partition capacity', :disk do

        every 1.minute

        match type: 'resource', category: 'disk'

        exec( Arborist::Monitor::SNMP::Disk )

    end

    Arborist::Monitor 'process checks', :proc do

        every 1.minute

        match type: 'resource', category: 'process'

        exec( Arborist::Monitor::SNMP::Process )

    end

    Arborist::Monitor 'memory', :memory do

        every 1.minute

        match type: 'resource', category: 'memory'

        exec( Arborist::Monitor::SNMP::Memory )

    end

Additionally, if you'd like these SNMP monitors to rely on the SNMP

service itself, you can add a UDP check for that.

    Arborist::Monitor 'udp service checks', :udp do

        every 30.seconds

        match type: 'service', protocol: 'udp'

        exec( Arborist::Monitor::Socket::UDP )

    end

And a default node declaration:

    Arborist::Host 'example' do

        description 'An example host'

        address 'demo.example.com'

        resource 'cpu'

        resource 'memory'

        resource 'disk'

    end

All configuration can be overridden from the defaults using the `config`

pragma, per node.  Here's a more elaborate example that performs the following:

  * All SNMP monitored resources are quieted if the SNMP service itself is unavailable.

  * Only monitor specific disk partitions, warning at different capacities .

  * Ensure the 'important' processing is running with the '--production' flag.

  * Warns at 95% memory utilization OR 10% swap.

    Arborist::Host 'example' do

        description 'An example host'

        address 'demo.example.com'

        service 'snmp', protocol: 'udp'

        resource 'cpu', description: 'machine cpu load' do

            depends_on 'example-snmp'

        end

        resource 'memory', description: 'machine ram and swap' do

            depends_on 'example-snmp'

            config physical_warn_at: 95, swap_warn_at: 10

        end

        resource 'disk', description: 'partition capacity' do

            depends_on 'example-snmp'

            config \

                include: [

                    '^/tmp',

                    '^/var'

                ],

                warn_at: {

                        '/tmp' => 50,

                        '/var' => 80

                }

        end

        resource 'process' do

            depends_on 'example-snmp'

            config check: 'important --production'

        end

    end

## License

Copyright (c) 2016-2018 Michael Granger and Mahlon E. Smith

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,

  this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice,

  this list of conditions and the following disclaimer in the documentation

  and/or other materials provided with the distribution.

* Neither the name of the author/s, nor the names of the project's

  contributors may be used to endorse or promote products derived from this

  software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE

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