Sensu-Puppet

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Upgrade note

Versions prior to 1.0.0 are incompatible with previous versions of the Sensu-Puppet module.

Installation

$ puppet module install sensu/sensu

Prerequisites

• Redis server and connectivity to a Redis database
• RabbitMQ server, vhost, and credentials

Dependencies

• puppetlabs/apt
• puppetlabs/stdlib

See Modulefile for details.

Pluginsync should be enabled. Also, you will need the Ruby JSON library or gem on all your nodes.

EPEL

Rubygem:

$ sudo gem install json

Debian & Ubuntu:

$ sudo apt-get install ruby-json

Basic example

Sensu server

node 'sensu-server.foo.com' {
  class { 'sensu':
    rabbitmq_password => 'secret',
    server            => true,
    dashboard         => true,
    api               => true,
    plugins           => [
      'puppet:///data/sensu/plugins/ntp.rb',
      'puppet:///data/sensu/plugins/postfix.rb'
    ]
  }

  sensu::handler { 'default':
    command => 'mail -s \'sensu alert\' ops@foo.com',
  }

  sensu::check { 'check_ntp':
    command     => 'PATH=$PATH:/usr/lib/nagios/plugins check_ntp_time -H pool.ntp.org -w 30 -c 60',
    handlers    => 'default',
    subscribers => 'sensu-test'
  }

  sensu::check { '...':
    ...
  }
}

Sensu client

node 'sensu-client.foo.com' {
   class { 'sensu':
     rabbitmq_password  => 'secret',
     rabbitmq_host      => 'sensu-server.foo.com',
     subscriptions      => 'sensu-test',
   }
}

Advanced example using Hiera

This example includes the sensu class as part of a base class or role and configures Sensu on each individual node via Hiera.

hiera.yaml

---
:hierarchy:
  - %{fqdn}
  - %{datacenter}
  - common
:backends:
  - yaml
:yaml:
  :datadir: '/etc/puppet/%{environment}/modules/hieradata'

common.yaml

sensu::dashboard_port: 8090
sensu::dashboard_password: mysupersecretpassword
sensu::install_repo: 'false'
sensu::purge_config: true
sensu::rabbitmq_host: 10.31.0.90
sensu::rabbitmq_password: password
sensu::rabbitmq_port: 5672

sensu-server.foo.com.yaml

sensu::server: true

nosensu.foo.com.yaml

sensu::client: 'false'

site.pp

node default {
  class { 'sensu': }
  ...
}

Safe Mode checks

By default Sensu clients will execute whatever check messages are on the queue. This is potentially a large security hole.

If you enable the safe_mode parameter, it will require that checks are defined on the client. If standalone checks are used then defining on the client is sufficient, otherwise checks will also need to be defined on the server as well.

A usage example is shown below.

Sensu server

Each component of Sensu can be controlled separately. The server components are managed with the server, dashboard, and API parameters.

node 'sensu-server.foo.com' {
  class { 'sensu':
    rabbitmq_password => 'secret',
    server            => true,
    dashboard         => true,
    api               => true,
    plugins           => [
      'puppet:///data/sensu/plugins/ntp.rb',
      'puppet:///data/sensu/plugins/postfix.rb'
    ],
    safe_mode         => true,
  }

  ...

  sensu::check { "diskspace":
    command => '/etc/sensu/plugins/system/check-disk.rb',
  }


}

Sensu client

node 'sensu-client.foo.com' {
   class { 'sensu':
     rabbitmq_password  => 'secret',
     rabbitmq_host      => 'sensu-server.foo.com',
     subscriptions      => 'sensu-test',
     safe_mode          => true,
   }

  sensu::check { "diskspace":
    command => '/etc/sensu/plugins/system/check-disk.rb',
  }
}

Using custom variables in check definitions

sensu::check{ 'check_file_test':
  command      => '/usr/local/bin/check_file_test.sh',
  handlers     => 'notifu',
  custom       => {
    'foo'      => 'bar',
    'numval'   => 6,
    'boolval'  => true,
    'in_array' => ['foo','baz']
  },
  subscribers  => 'sensu-test'
}

This will create the following check definition for Sensu:

{
  "checks": {
    "check_file_test": {
      "handlers": [
        "notifu"
      ],
      "in_array": [
        "foo",
        "baz"
      ],
      "command": "/usr/local/bin/check_file_test.sh",
      "subscribers": [
        "sensu-test"
      ],
      "foo": "bar",
      "interval": 60,
      "numval": 6,
      "boolval": true
    }
  }
}

Handler configuration

sensu::handler {
  'handler_foobar':
    command => '/etc/sensu/handlers/foobar.py',
    type    => 'pipe',
    config  => {
      'foobar_setting' => 'value',
  }
}

This will create the following handler definition for Sensu (server):

 {
   "handler_foobar": {
     "foobar_setting": "value"
   },
   "handlers": {
      "handler_foobar": {
        "command": "/etc/sensu/plugins/foobar.py",
        "severities": [
          "ok",
          "warning",
          "critical",
          "unknown"
        ],
      "type": "pipe"
      }
   }
 }

Disable Service Management

If you'd prefer to use an external service management tool such as DaemonTools or SupervisorD, you can disable the module's internal service management functions like so:

sensu::manage_services: false

Including Sensu monitoring in other modules

There are a few different patterns that can be used to include Sensu monitoring into other modules. One pattern creates a new class that is included as part of the host or node definition and includes a standalone check, for example:

apache/manifests/monitoring/sensu.pp

class apache::monitoring::sensu {
  sensu::check { 'apache-running':
    handlers    => 'default',
    command     => '/etc/sensu/plugins/check-procs.rb -p /usr/sbin/httpd -w 100 -c 200 -C 1',
    custom      => {
      refresh     => 1800,
      occurrences => 2,
    },
  }
}

You could also include subscription information and let the Sensu server schedule checks for this service as a subscriber:

apache/manifests/monitoring/sensu.pp

class apache::monitoring::sensu {
  sensu::subscription { 'apache': }
}

If you would like to automatically include the Sensu monitoring class as part of your existing module with the ability to support different monitoring platforms, you could do something like:

apache/manifests/service.pp

$monitoring = hiera('monitoring', '')

case $monitoring {
  'sensu':  { include apache::monitoring::sensu }
  'nagios': { include apache::monitoring::nagios }
}

License

See LICENSE file.