Class: CapELB

Inherits:
Object
  • Object
show all
Defined in:
lib/capistrano-elb.rb

Instance Method Summary collapse

Constructor Details

#initialize(configdir = File.join(Dir.pwd, 'config')) ⇒ CapELB

Returns a new instance of CapELB.



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# File 'lib/capistrano-elb.rb', line 13

def initialize(configdir=File.join(Dir.pwd, 'config'))
  ec2credentials = YAML::load(File.open(File.join(configdir, 'ec2credentials.yaml')))
  aws = Fog::Compute.new(ec2credentials.merge({:provider=>'AWS'}))
  @regions = aws.describe_regions.body["regionInfo"].map {|region| region["regionName"]}
  @compute = {}
  @regions.each do |region|
    @compute.merge!(region => Fog::Compute.new(ec2credentials.merge({:provider=>'AWS',:region=>region})))
  end

  @elb = {}
  @regions.each do |region|
    @elb.merge!(region => Fog::AWS::ELB.new(ec2credentials.merge(:region=>region)))
  end
  
  @lbs = config_from_tags
end

Instance Method Details

#add(serverlist) ⇒ Object 



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# File 'lib/capistrano-elb.rb', line 68

def add(serverlist)
  @lbs.each_pair do |region, lbs|
    lbs.each_pair do |lbname, target_instances|
      server_ids = @compute[region].servers.select{|server| serverlist.include? server.dns_name}.map{|server| server.id}
      to_change = server_ids.select{|server_id| target_instances.include? server_id}
      unless to_change.empty?
        puts "Adding #{to_change} to LB #{lbname} in #{region}" 
        @elb[region].register_instances_with_load_balancer(to_change, lbname) 
      end
    end
  end
end

#check_config ⇒ Object 



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# File 'lib/capistrano-elb.rb', line 54

def check_config
  current = config_from_lb
  errors = []
  @lbs.each_pair do |region,lbs|
    lbs.each_pair do |lbname, target_instances|
      missing = target_instances - current[region][lbname]
      extra = current[region][lbname] - target_instances
      errors << "#{missing} are missing from #{region}/#{lbname}" unless missing.empty?
      errors << "#{extra} should not be in #{region}/#{lbname}" unless extra.empty?
    end
  end
  (errors.empty? ? "ELB config correct" : errors) 
end

#config_from_lb ⇒ Object 



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# File 'lib/capistrano-elb.rb', line 40

def config_from_lb
  lbs = {}
  @regions.each do |region| 
    @elb[region].load_balancers.each do |lb|
      lbs.merge!({region => {lb.id => lb.instances}})
    end
  end
  lbs
end

#config_from_tags ⇒ Object 



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# File 'lib/capistrano-elb.rb', line 30

def config_from_tags
  lbs = {}
  @regions.each do |region| 
    @elb[region].load_balancers.each do |lb|
      lbs.merge!({region => {lb.id => get_instances(region,lb.id)}})
    end
  end
  lbs
end

#get_instances(region, lbname) ⇒ Object 



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# File 'lib/capistrano-elb.rb', line 50

def get_instances(region,lbname)
  @compute[region].tags.select{|tag| tag.key == 'elb' and tag.value==lbname}.map(&:resource_id)
end

#remove(serverlist) ⇒ Object 



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# File 'lib/capistrano-elb.rb', line 81

def remove(serverlist)
  @lbs.each_pair do |region, lbs|
    lbs.each_pair do |lbname, target_instances|
      server_ids = @compute[region].servers.select{|server| serverlist.include? server.dns_name}.map{|server| server.id}
      to_change = server_ids.select{|server_id| target_instances.include? server_id}
      unless to_change.empty?
        puts "Removing #{to_change} from LB #{lbname} in #{region}"        
        @elb[region].deregister_instances_from_load_balancer(to_change, lbname)
      end
    end
  end
end