sensu-transport-snssqs

sensu-transport-snssqs is a Sensu transport that produces messages over Amazon SNS and consumes messages from Amazon SQS, providing simplified monitoring using Sensu.

Messages flow from hosts onto an Amazon SNS topic. It is up to the operator to ensure that messages from the SNS topic flow to one SQS queue for consumption by the Sensu server.

Architecture

Messages flow unidirectionally: from the monitored hosts to the Sensu server. In this diagram, an SNS topic is created for each monitoring environment. Hosts within these environments publish messages onto their environment's SNS topic. All of these SNS topics place messages onto a single SQS queue. This singular SQS queue is consumed by the Sensu cluster to act on messages.

Caveats

• This transport is compatible with Sensu 0.23.0 and presumably, later versions.

• Subscription-based checks are not supported. Sensu subscriptions require the transport to be two-way: The Sensu server must be able to send a message through the transport to a specific host. SQS has no way of filtering messages in an SQS queue. Therefore, to use this transport, you can only use standalone checks.

• This transport assumes that SNS is publishing to your SQS queue in "Raw" mode.

• This transport assumes that Sensu's process environment is properly configured to use the aws-sdk gem.

Installation

To use this snssqs transport, this gem must be in your Sensu installation's ruby include path.

If you're installing Sensu via Chef, you can use the sensu_gem resource to ensure the gem is in Sensu's ruby include path:

sensu_gem 'sensu-transport-snssqs' do
  action :install
end

Otherwise, if you're running Sensu via bundler, add this line to your Sensu installation's Gemfile:

gem 'sensu-transport-snssqs'

That should place this gem into the include path.

Configuration

First, we need to enable the snssqs transport. To do so, ensure that the following transport clause is in your configuration:

{
  "transport": {
    "name": "snssqs",
    "reconnect_on_error": true,
   }
}

Now that the SNSSQS transport has been enabled, configure it using an snssqs clause:

{
  "snssqs": {
    "max_number_of_messages": 10,
    "wait_time_seconds": 2,
    "region": "{{ AWS_REGION }}",
    "consuming_sqs_queue_url": "{{ SENSU_QUEUE_URL }}",
    "publishing_sns_topic_arn": "{{ SENSU_SNS_ARN }}"
    },
}

The following table lists possible settings and their descriptions. The values should be JSON strings unless specified otherwise.

Setting	Description
max_number_of_messages	The maximum number of messages to consume when consuming from SQS. This option is piped directly to the SQS client receive_message method. Setting this to the maximum possible value is the best way to improve performance. (JSON Number)
wait_time_seconds	The number of seconds to wait while polling for messages from SQS. Keeping this value too high will cause Sensu's EventMachine reactor to block while waiting for messages for possibly too long. As a result, this value should typically be low. This option is used directly in the SQS client receive_message method. (JSON Number)
region	The region to specify when initializing the AWS SNS and SQS clients.
consuming_sqs_queue_url	The SQS Queue URL for which you want Sensu to consume from.
publishing_sns_topic_arn	The SNS Topic ARN for which you want Sensu to publish messages to.
statsd_addr	Address to send statsd metrics to. If not set, the transport will not emit metrics to statsd.
statsd_namespace	Prefix to prepend to all statsd metrics. Should not end with a period.
statsd_sample_rate	Set the sample rate for all statsd operations. This should be a string with a value between 0 and 1.0.

License

sensu-transport-snssqs is released under the Apache 2.0 License, full copy of which is inside of the LICENSE file.