Nagios server cookbook. Part that dumps the configuration on the disk.

server.rb

ruby_block "Delete Legacy Files" do
  block do
    existing = []
    Dir.new('/etc/nagios3/conf.d/').each do |f|
      next if f == '.' or f == '..' 
      existing << f
    end
    reals = search(:node, "monitored:[* TO *]").map{ |n| n[:fqdn] +".cfg" }

    (existing - reals).each do |leftover|
      next if leftover !~ /#{node[:domain]}\.cfg$/
      File.unlink('/etc/nagios3/conf.d/'+leftover)
    end
  end
end
 
# get all the monitored servers
monitored = {} 
search(:node, "monitored:[* TO *]").map do |nod| 
  monitored[nod[:hostname]] = nod.to_hash
end

monitored.each do |hostname, n|
  begin
    services = n['monitored']['current']
  rescue Exception=>e
    Chef::Log.error("Failed to get current monitored states")
    Chef::Log.error("State is "+n.inspect)
    raise e
  end

  services.each do |service, s|
    depends = s['depends'] || []
    new_depends = []
    # For each dependency find the nodes which hosts this service and build the dependency string accordingly
    depends.each do |parent|
      # Dependencies on "@localhost" are replace by real hostname
      if parent.index("@localhost") != nil
        new_depends << parent[0..parent.index("@")] + hostname
      end

      monitored.select { |h,reg|
        begin
          reg['monitored']['current'].include?(parent)
        rescue Exception => e
          Chef::Log.error("Unable to look at monitored current in #{h}"+e.to_s)
          false
        end
      }.each { |match|
        new_depends << parent + "@" + match[0]
      }
      Chef::Log.warn("#{parent} not found in services (#{service} depends on it). This is not normal.") if new_depends.length == 0
    end
    new_depends.uniq!
    s['depends'] = new_depends
    Chef::Log.debug("Service #{service} on #{hostname} depends on "+new_depends.inspect)
  end

  template "/etc/nagios3/conf.d/#{n['fqdn']}.cfg" do
    owner "nagios"
    group "nagios"
    mode 0644
    backup false
    source "services.cfg.erb"
    variables (:host => n, :services => services)
    notifies :reload, resources('service[nagios3]')
  end
end