Class: Nines::App

Inherits:
Object
  • Object
show all
Defined in:
lib/nines/app.rb

Class Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config_file) ⇒ App

Returns a new instance of App.



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# File 'lib/nines/app.rb', line 14

def initialize(config_file)
  self.class.root = File.expand_path('../../../', __FILE__)
  
  # load config files
  case File.extname(config_file)
    when '.yml' then self.class.config = YAML.load(ERB.new(File.read(config_file)).result)
    when '.rb'  then require config_file
  end
  self.class.config = stringify_keys_and_symbols(self.class.config)
  
  # set main parameters
  self.class.debug      = config['debug']
  self.class.verbose    = config['verbose']
  
  self.class.logfile    = config['logfile'] || 'nines.log'
  self.class.pidfile    = config['pidfile'] || 'nines.pid'
  self.class.email_from = config['email_from'] || 'Nines Notifier <[email protected]>'
  self.class.email_subject_prefix = config['email_subject_prefix'] || ''
end

Class Attribute Details

.config ⇒ Object

Returns the value of attribute config.



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# File 'lib/nines/app.rb', line 9

def config
  @config
end

.continue ⇒ Object

Returns the value of attribute continue.



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# File 'lib/nines/app.rb', line 9

def continue
  @continue
end

.debug ⇒ Object

Returns the value of attribute debug.



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# File 'lib/nines/app.rb', line 9

def debug
  @debug
end

.email_from ⇒ Object

Returns the value of attribute email_from.



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# File 'lib/nines/app.rb', line 9

def email_from
  @email_from
end

.email_subject_prefix ⇒ Object

Returns the value of attribute email_subject_prefix.



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# File 'lib/nines/app.rb', line 9

def email_subject_prefix
  @email_subject_prefix
end

.logfile ⇒ Object

Returns the value of attribute logfile.



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# File 'lib/nines/app.rb', line 9

def logfile
  @logfile
end

.logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/nines/app.rb', line 9

def logger
  @logger
end

.notifier ⇒ Object

Returns the value of attribute notifier.



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# File 'lib/nines/app.rb', line 9

def notifier
  @notifier
end

.pidfile ⇒ Object

Returns the value of attribute pidfile.



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# File 'lib/nines/app.rb', line 9

def pidfile
  @pidfile
end

.root ⇒ Object

Returns the value of attribute root.



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# File 'lib/nines/app.rb', line 9

def root
  @root
end

.verbose ⇒ Object

Returns the value of attribute verbose.



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# File 'lib/nines/app.rb', line 9

def verbose
  @verbose
end

Instance Method Details

#check_hostnames ⇒ Object

make sure you’re not using OpenDNS or something else that resolves invalid names



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# File 'lib/nines/app.rb', line 88

def check_hostnames
  all_good = true
  
  @check_groups.each do |group|
    group.checks.each do |check|
      unless check.hostname && Dnsruby::Resolv.getaddress(check.hostname)
        puts "Error: check #{check.name} has invalid hostname '#{check.hostname}'"
        all_good = false
      end
    end
  end
  
  all_good
end

#config ⇒ Object

shortcuts



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# File 'lib/nines/app.rb', line 35

def config    ; self.class.config   ; end

#configure_smtp ⇒ Object 



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# File 'lib/nines/app.rb', line 103

def configure_smtp
  if config['smtp'].is_a?(Hash)
    Mail.defaults do
      delivery_method :smtp, { 
        :address => Nines::App.config['smtp']['address'] || 'localhost',
        :port => Nines::App.config['smtp']['port'] || 25,
        :domain => Nines::App.config['smtp']['domain'],
        :user_name => Nines::App.config['smtp']['user_name'],
        :password => Nines::App.config['smtp']['password'],
        :authentication => (Nines::App.config['smtp']['authentication'] || 'plain').to_sym,
        :enable_starttls_auto => Nines::App.config['smtp']['enable_starttls_auto'],
        :tls => Nines::App.config['smtp']['tls'],
      }
    end
  end
end

#debug ⇒ Object 



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# File 'lib/nines/app.rb', line 38

def debug     ; self.class.debug    ; end

#logfile ⇒ Object 



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# File 'lib/nines/app.rb', line 36

def logfile   ; self.class.logfile  ; end

#logfile_writable ⇒ Object 



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# File 'lib/nines/app.rb', line 67

def logfile_writable
  begin
    File.open(logfile, 'a') { }
    true
  rescue Exception => e
    puts "Exception: #{e}"
    false
  end
end

#logger ⇒ Object 



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# File 'lib/nines/app.rb', line 39

def logger    ; self.class.logger   ; end

#pidfile ⇒ Object 



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# File 'lib/nines/app.rb', line 37

def pidfile   ; self.class.pidfile  ; end

#pidfile_writable ⇒ Object 



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# File 'lib/nines/app.rb', line 77

def pidfile_writable
  begin
    File.open(pidfile, 'a') { }
    true
  rescue Exception => e
    puts "Exception: #{e}"
    false
  end
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/nines/app.rb', line 41

def running?
  pid = nil
  
  begin
    pid = File.open(pidfile).read.to_i
    return false if pid == 0
  rescue
    # puts "Pidfile doesn't exist"
    return false
  end
  
  begin
    Process.kill(0, pid)
    # puts "#{pid} is running"
    return true
  rescue Errno::EPERM
    # puts "No permission to query #{pid}!"
  rescue Errno::ESRCH
    # puts "#{pid} is NOT running."
  rescue
    # puts "Unable to determine status for #{pid} : #{$!}"
  end
  
  false
end

#start(options = {}) ⇒ Object 



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# File 'lib/nines/app.rb', line 134

def start(options = {})
  # set up logger
  self.class.logger = Logger.new(debug ? STDOUT : File.open(logfile, 'a'))
  logger.sync = 1  # makes it possible to tail the logfile
  
  # use it
  logger.puts "[#{Time.now}] - nines starting"
  
  # set up notifier
  configure_smtp
  self.class.notifier = Notifier.new(config['contacts'])
  
  # set up check_groups (uses logger and notifier)
  if !config['check_groups'].is_a?(Array) || config['check_groups'].empty?
    raise Exception.new("No check groups configured, nothing to do.")
  end
  
  @check_groups = []
  config['check_groups'].each do |options|
    @check_groups << CheckGroup.new(options)
  end
  
  # TODO: this is a little awkwardly placed, but can fix later
  unless check_hostnames
    puts "Invalid hostnames found in config file"
    exit 1
  end
  
  # fork and detach
  if pid = fork
    File.open(pidfile, 'w') { |f| f.print pid }
    puts "Background process started with pid #{pid} (end it using `#{$0} stop`)"
    puts "Debug mode enabled, background process will log to STDOUT and exit after running each check once." if debug
    exit 0
  end
  
  #
  # rest of this method runs as background process
  #
  
  # trap signals before spawning threads
  self.class.continue = true
  trap("INT") { Nines::App.continue = false ; puts "Caught SIGINT, will exit after current checks complete or time out." }
  trap("TERM") { Nines::App.continue = false ; puts "Caught SIGTERM, will exit after current checks complete or time out." }
  
  # iterate through config, spawning check threads as we go
  @threads = []
  
  @check_groups.each do |group|
    group.checks.each do |check|
      @threads << Thread.new(Thread.current) { |parent|
        begin
          check.run
        rescue Exception => e
          parent.raise e
        end
      }
    end
  end
  
  @threads.each { |t| t.join if t.alive? }
  
  logger.puts "[#{Time.now}] - nines finished"
  logger.close
  
  File.unlink(pidfile)
  
  puts "Background process finished"
end

#stop(options = {}) ⇒ Object 



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# File 'lib/nines/app.rb', line 204

def stop(options = {})
  begin
    pid = File.read(pidfile).to_i
    if pid == 0
      STDERR.puts "nines does not appear to be running."
      exit 1
    end
  rescue Errno::ENOENT => e
    STDERR.puts "Couldn't open pid file #{pidfile}, please check your config."
    exit 1
  end
  
  begin
    Process.kill "INT", pid
    exit 0
  rescue Errno::EPERM => e
    STDERR.puts "Couldn't kill process with pid #{pid}, appears to be owned by someone else."
    exit 1
  rescue Errno::ESRCH => e
    STDERR.puts "Couldn't kill process with pid #{pid}. Are you sure it's running?"
    exit 1
  end
end

#stringify_keys_and_symbols(obj) ⇒ Object 



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# File 'lib/nines/app.rb', line 120

def stringify_keys_and_symbols(obj)
  case obj.class.to_s
  when 'Array'
    obj.map! { |el| stringify_keys_and_symbols(el) }
  when 'Hash'
    obj.stringify_keys!
    obj.each { |k,v| obj[k] = stringify_keys_and_symbols(v) }
  when 'Symbol'
    obj = obj.to_s
  end
  
  obj
end