New check for checking HTTP responses for each instances on a ELB

CHANGELOG.md

@@ -4,6 +4,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This CHANGELOG follows the format listed at [Keep A Changelog](http://keepachangelog.com/)
 
 ## [Unreleased]
+### Added
+- check-elb-instances-endpoints.rb: Check each instance attached to a ELB for a HTTP 200 response (@markwallsgrove)
 
 ## [8.3.0] - 2017-09-16
 ### Added

README.md

@@ -60,6 +60,8 @@
 
 **check-elb-health.rb**
 
+**check-elb-instances-endpoints.rb**
+
 **check-elb-instances-inservice.rb**
 
 **check-elb-latency.rb**
@@ -176,6 +178,7 @@
 * /bin/check-elb-health-fog.rb
 * /bin/check-elb-health-sdk.rb
 * /bin/check-elb-health.rb
+  /bin/check-elb-instances-endpoints.rb
 * /bin/check-elb-instances-inservice.rb
 * /bin/check-elb-latency.rb
 * /bin/check-elb-nodes.rb

bin/check-elb-instances-endpoints.rb

@@ -0,0 +1,197 @@
+#! /usr/bin/env ruby
+#
+# check-elb-instances-endpoints
+#
+# DESCRIPTION:
+#   This plugin checks for a HTTP 200 against each instance attached to a ELB.
+#
+# OUTPUT:
+#   plain-text
+#
+# PLATFORMS:
+#   Linux
+#
+# DEPENDENCIES:
+#   gem: aws-sdk
+#   gem: sensu-plugin
+#
+# USAGE:
+#
+#   Check each instance on the elb returns a HTTP200 on the path /
+#   check-elb-instances-endpoints.rb -n ELBNAME -p /
+#
+#   Check each instance on the elb returns a HTTP200 on the path / and use https
+#   check-elb-instances-endpoints.rb -n ELBNAME -p / -s
+#
+#   Check each instance on the elb returns a HTTP200 on the path / using port 8080
+#   check-elb-instances-endpoints.rb -n ELBNAME -p / -P 8080
+#
+#   Check each instance on the elb returns a HTTP200 on the path / in a given AWS region
+#   check-elb-instances-endpoints.rb -n ELBNAME -p / -r eu-west-1
+#
+# LICENSE:
+#    MIT License
+#
+#    Copyright (c) 2017 Claranet
+#
+#    Permission is hereby granted, free of charge, to any person obtaining a copy
+#    of this software and associated documentation files (the "Software"), to deal
+#    in the Software without restriction, including without limitation the rights
+#    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+#    copies of the Software, and to permit persons to whom the Software is
+#    furnished to do so, subject to the following conditions:
+#
+#    The above copyright notice and this permission notice shall be included in all
+#    copies or substantial portions of the Software.
+#
+#    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+#    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+#    SOFTWARE.
+#
+
+require 'sensu-plugin/check/cli'
+require 'aws-sdk-v1'
+
+# check each node by calling a http endpoint
+class HTTPCheckELBNodes < Sensu::Plugin::Check::CLI
+  option :aws_access_key,
+         short: '-a AWS_ACCESS_KEY',
+         long: '--aws-access-key AWS_ACCESS_KEY',
+         description: "AWS Access Key. or use ENV['AWS_ACCESS_KEY']",
+         default: ENV['AWS_ACCESS_KEY']
+
+  option :aws_secret_access_key,
+         short: '-k AWS_SECRET_KEY',
+         long: '--aws-secret-access-key AWS_SECRET_KEY',
+         description: "AWS Secret Access Key or use ENV['AWS_SECRET_KEY']",
+         default: ENV['AWS_SECRET_KEY']
+
+  option :aws_region,
+         short: '-r AWS_REGION',
+         long: '--aws-region REGION',
+         description: 'AWS Region (defaults to eu-west-1)',
+         default: 'eu-west-1'
+
+  option :instance_name,
+         short: '-n ELB_NAME',
+         long: '--name ELB_NAME',
+         description: 'Regular expression to describe the elb name',
+         required: true
+
+  option :path,
+         short: '-p PATH',
+         long: '--path PATH',
+         description: 'path to check',
+         required: true
+
+  option :use_http,
+         long: '--http',
+         description: 'use http (default: false)',
+         boolean: true,
+         default: false
+
+  option :port,
+         short: '-P PORT',
+         long: '--port PORT',
+         description: 'HTTP port',
+         default: 0,
+         proc: proc(&:to_i)
+
+  option :timeout,
+         long: '--timeout TIMEOUT',
+         description: 'HTTP timeout',
+         default: 2,
+         proc: proc(&:to_i)
+
+  option :private_dns,
+         long: '--private-dns',
+         description: 'Use the private DNS name (default is the public dns)',
+         default: false,
+         boolean: true
+
+  option :response_code,
+         long: '--response-code',
+         description: 'Expected response code (default HTTP200)',
+         default: '200'
+
+  def aws_config
+    { access_key_id: config[:aws_access_key],
+      secret_access_key: config[:aws_secret_access_key],
+      region: config[:aws_region] }
+  end
+
+  def run
+    instances = get_instances((AWS::ELB.new aws_config))
+    errors = {}
+
+    instances.each do |inst|
+      resp = call_endpoint(inst)
+      errors[inst.id] = resp unless resp.nil?
+    end.empty? && begin
+      errors['amount'] = 'zero instances found'
+    end
+
+    errors.keys.count.zero? ? (ok 'all is good') : (critical errors.to_s)
+  end
+
+  def get_instances(elbs)
+    instances = []
+    elbs.load_balancers.each do |elb|
+      elb.instances.each { |instance| instances << instance if /#{config[:instance_name]}/ =~ instance.tags['Name'] }
+    end
+    instances
+  rescue => e
+    unknown "retrieving load balancer describtors: #{e}"
+  end
+
+  def name
+    config[:load_balancer_name]
+  end
+
+  def call_endpoint(inst)
+    url = URI("#{schema}://#{host(inst)}#{port}#{path}")
+    http = Net::HTTP.new(url.host, url.port)
+    http.read_timeout = timeout
+    http.open_timeout = timeout
+    resp = http.start { |session| session.get(url.path) }
+    invalid_code = resp.code != response_code
+    return 'Page not found' if invalid_code && resp.code == '404'
+    return 'Invalid status' if invalid_code && resp.body.empty?
+    return resp.body if invalid_code
+    nil
+  rescue
+    'Timeout'
+  end
+
+  def host(inst)
+    private_dns ? inst.private_dns_name : inst.public_dns_name
+  end
+
+  def private_dns
+    config[:private_dns]
+  end
+
+  def timeout
+    config[:timeout]
+  end
+
+  def schema
+    config[:use_http] ? 'http' : 'https'
+  end
+
+  def port
+    config[:port].zero? ? '' : ":#{config[:port]}"
+  end
+
+  def path
+    config[:path]
+  end
+
+  def response_code
+    config[:response_code]
+  end
+end