Infrastructure as Code & Monitoring

Automacon 2015 talk: Infrastructure as Code & monitoring, sharing the same development workflow.

Transcript

1. Infrastructure as Code &
   Monitoring
   Sharing the same development workflow.
   

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2. Sean Porter
   @PorterTech
   

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3. FOCUS
   ● The Sensu origin story - where it came from
   ● What makes Sensu different
   ● IaC development workflows
   ● Testing & monitoring in an IaC workflow
   ● Chef & Sensu in practice
   

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5. THE SENSU ORIGIN STORY
   ● I started at Sonian ~ 2010
   ○ Chef 0.7 with AWS #YOLO infrastructure
   ○ Several traditional monitoring tools:
   Nagios, Ganglia, Collectd, & Graphite
   

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6. ~ 50 alerts a day
   Mostly noise.
   

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7. THE SENSU ORIGIN STORY
   Triggered @lusis to write: “Why Monitoring Sucks”
   

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8. Wanted MOAR!
   

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9. Build it.
   Automatic (de)registration
   Config Management friendly
   Secure connectivity
   REST API
   Elastic scalability
   UNIX
   

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10. July 11th, 2011
    

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11. What makes Sensu different?
    What makes it better for CM driven environments?
    

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13. JSON CONFIGURATION
    {
    "checks": {
    "mysql_replication": {
    "command": "check-mysql-replication.rb",
    "subscribers": ["mysql"],
    "interval": 30,
    "playbook": "http://wiki.example.com/mysql-replication-playbook"
    }
    }
    }
    

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14. CHECK EXECUTION METHODS
    ● Pub/Sub (central orchestration)
    ○ e.g. execute http check on all API nodes
    ● Standalone
    ○ Define checks while provisioning node(s)
    ○ Scheduled by the local Sensu client
    

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15. LOCAL CLIENT SOCKET
    echo '{ \
    "name": "mysql_backup", \
    "output": "could not connect to mysql", \
    "status": 2, \
    "ttl": 90000 }' | nc localhost 3030
    

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17. Let’s talk about IaC workflows
    “The sequence of processes through which a piece of
    work passes from initiation to completion” - Google.
    

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18. BASIC IaC WORKFLOW
    “It’s all software.”
    

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19. BASIC IaC WORKFLOW
    

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20. BASIC IaC WORKFLOW
    “It’s all software.”
    

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21. BASIC IaC WORKFLOW
    Use tests. Still need to review tests & code quality.
    

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22. BASIC IaC WORKFLOW
    TEST ≈ MONITOR
    

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23. BASIC IaC WORKFLOW
    Shorten the feedback loop.
    

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24. Writing IaC tests
    “A procedure intended to establish the quality, performance,
    or reliability of something, especially before it is taken into
    widespread use” - Google.
    

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25. TESTING TOOLS
    ● Serverspec
    ○ RSpec tests for your servers
    ○ serverspec.org
    ● Bats
    ○ Bash Automated Testing System
    ○ Bash script with special syntax for defining
    test cases
    

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26. SERVERSPEC
    require 'spec_helper'
    describe service('httpd'), :if => os[:family] == 'redhat' do
    it { should be_enabled }
    it { should be_running }
    end
    describe port(80) do
    it { should be_listening }
    end
    

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27. BATS
    #!/usr/bin/env bats
    @test "httpd should be running" {
    run service httpd status
    [ "$status" -eq 0 ]
    }
    @test "httpd should be listening for connections" {
    [ "$(netstat -plant | grep httpd)" ]
    }
    

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28. RUNNING TESTS
    ● Test Kitchen
    ○ kitchen.ci
    ● Vagrant plugins
    ○ github.com/jvoorhis/vagrant-serverspec
    ● Serverspec SSH
    ● … choose your own adventure!
    

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29. RUNNING TESTS AS SENSU CHECKS
    ● Use the Sensu Serverspec check plugin
    ○ gem install sensu-plugins-serverspec
    check-serverspec.rb \
    -d /etc/sensu/serverspec -t '*_spec.rb'
    ● Run Bats scripts
    

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30. Chef & Sensu
    In practice.
    

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31. SENSU CHEF COOKBOOK
    supermarket.chef.io/cookbooks/sensu
    ● Recipes to install & manage services
    ● LWRPs for configuring handlers, checks, etc.
    ● Intended to be used by wrapper cookbook
    ○ e.g. recipe['monitor::haproxy']
    

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32. EXAMPLE CHEF RESOURCES
    sensu_handler 'default' do # recipe['monitor::_handlers']
    type 'pipe'
    command 'pagerduty.rb'
    end
    sensu_check 'redis_process' do # recipe['monitor::redis']
    command 'check-procs.rb -p redis-server -w 2 -c 3 -C 1'
    standalone true
    interval 30
    end
    

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33. USING DATA BAGS
    # recipe['monitor::pubsub']
    data_bag('sensu_checks').each do |data_bag_item|
    check = data_bag_item('sensu_checks', data_bag_item)
    sensu_check check['id'] do
    check.each do |key, value|
    send(key.to_sym, value) if respond_to?(key.to_sym)
    end
    end
    end
    

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34. SENSU SERVERSPEC CHECKS
    # recipe['monitor::serverspec']
    sensu_gem 'sensu-plugins-serverspec'
    sensu_check 'serverspec' do
    command 'check-serverspec.rb -d /etc/sensu/serverspec -t \*_spec.rb '
    standalone true
    interval 30
    end
    # e.g. CheckServerspec CRITICAL: 12 examples, 2 failures
    

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35. BASIC IaC WORKFLOW
    TEST ≈ MONITOR
    

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36. Questions?
    Sean Porter (@PorterTech)
    sensuapp.org
    

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