icinga2_ec2

#!/usr/bin/env ruby

#/******************************************************************************
# * Icinga 2 AWS                                                               *
# * Copyright (C) 2015 Icinga Development Team (https://www.icinga.org)        *
# *                                                                            *
# * This program is free software; you can redistribute it and/or              *
# * modify it under the terms of the GNU General Public License                *
# * as published by the Free Software Foundation; either version 2             *
# * of the License, or (at your option) any later version.                     *
# *                                                                            *
# * This program is distributed in the hope that it will be useful,            *
# * but WITHOUT ANY WARRANTY; without even the implied warranty of             *
# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              *
# * GNU General Public License for more details.                               *
# *                                                                            *
# * You should have received a copy of the GNU General Public License          *
# * along with this program; if not, write to the Free Software Foundation     *
# * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
# ******************************************************************************/

require 'aws-sdk'
require 'rest_client'
require 'colorize'

class AwsInstanceManager
  def print_instance(inst)
    #puts inst
    iid = inst[:instance_id]
    istate = inst[:state].name
    ipublicdns = inst[:public_dns_name]
    ipublicip = inst[:public_ip_address]

    if istate != "running"
      puts "AWS EC2 instance ID: '#{iid}' State: '#{istate}'".red
    else
      puts "AWS EC2 instance ID: '#{iid}' State: '#{istate}' Public DNS: '#{ipublicdns}' Public IP: '#{ipublicip}'".green
    end
  end

  def manage_instances(i2)
    ec2 = Aws::EC2::Client.new(region: 'us-west-2');

    if !i2.check_running()
      puts "Icinga 2 API is not available. Please start Icinga 2 with enabled 'api' feature and appropriate api user credentials.".red
      exit 1
    end

    resp = ec2.describe_instances()
    resp.reservations.each do |res|
      res.instances.each do |inst|
#        puts inst
        i_id = inst[:instance_id]
        i_state = inst[:state].name
        i_public_dns = inst[:public_dns_name]
        i_public_ip = inst[:public_ip_address]

        print_instance(inst)

        # if instance is not running, mark it for deletion
        # TODO: allow user to define the action
        i_to_delete = false
        if i_state != "running"
          i_to_delete = true
        end

        # check if the host exists
        i2_res = i2.get_host(i_id)

        i_exists = false
        if i2_res && i2_res.code == 200
          #puts i2_res.body
          i_exist = true
        end

        if i_exists == false and i_to_delete == true
          # object was marked for deletion
          i2.delete_host(i_id)
        elsif i_exists == false and i_to_delete == false
          # object does not exist
          # TODO: add/fetch more tags as custom attributes
          tags = { "os" => "Linux", "distribution" => "AWS"}
          i2.create_host(i_id, i_public_ip, i_public_dns, tags)
        elsif i_exists == true and i_to_delete == false
          puts "Found host, doing update only".yellow
          # TODO: add/fetch more tags as custom attributes
          tags = { "os" => "Linux", "distribution" => "AWS"}
          i2.update_host(i_id, i_public_ip, i_public_dns, tags)
        end
      end
    end
  end
end

class Icinga2InstanceManager
  @@node_name = Socket.gethostbyname(Socket.gethostname).first 
  def set_node_name(name)
    @@node_name = name
  end

  @@api_username = "root"
  def set_api_username(str)
    @@api_username = str
  end
  @@api_password= "icinga"
  def set_api_password(str)
    @@api_password = str
  end

  @@api_url_base = "https://192.168.33.5:5665/v1"
  def set_api_url_base(url)
    @@api_url_base = url
  end

  @@api_url_obj_hosts = "/objects/hosts"

  # prepare the rest client ssl stuff
  def prepare_rest_client(api_url)

    # check whether pki files are there, otherwise use basic auth
    if File.file?("pki/" + @@node_name + ".crt")
      #puts "PKI found, using client certificates for connection to Icinga 2 API"
      cert_file = File.read("pki/" + @@node_name + ".crt")
      key_file = File.read("pki/" + @@node_name + ".key")
      ca_file = File.read("pki/ca.crt")

      cert = OpenSSL::X509::Certificate.new(cert_file)
      key = OpenSSL::PKey::RSA.new(key_file)

      options = {:ssl_client_cert => cert, :ssl_client_key => key, :ssl_ca_file => ca_file, :verify_ssl => OpenSSL::SSL::VERIFY_NONE}
    else
      #puts "PKI not found, using basic auth for connection to Icinga 2 API"

      options = { :user => @@api_username, :password => @@api_password, :verify_ssl => OpenSSL::SSL::VERIFY_NONE }
    end

    res = RestClient::Resource.new(URI.encode(api_url), options)
    return res
  end

  # fetch global status to see if api is available
  def check_running()
    api_url = @@api_url_base + "/status/IcingaApplication"
    rest_client = prepare_rest_client(api_url)
    headers = {"Content-Type" => "application/json", "Accept" => "application/json"}

    puts "Checking the availability of the Icinga 2 API at #{api_url}."

    begin
      response = rest_client.get(headers)
    rescue => e
      puts e
      return false
    end

    puts "Status: " + (JSON.pretty_generate JSON.parse(response.body))
    return true
  end

  # list, GET
  def get_host(name)
    api_url = @@api_url_base + @@api_url_obj_hosts + "/#{name}"
    rest_client = prepare_rest_client(api_url)
    headers = {"Content-Type" => "application/json", "Accept" => "application/json"}

    puts "Icinga 2: Getting host '#{name}'."

    begin
      response = rest_client.get(headers)
    rescue => e
      puts e
      e.response
    end
    #puts response
    return response
  end

  # create, PUT
  def create_host(name, address, display_name, tags)
    api_url = @@api_url_base + @@api_url_obj_hosts + "/#{name}"
    rest_client = prepare_rest_client(api_url)
    headers = {"Content-Type" => "application/json", "Accept" => "application/json"}
    # hardcode the required check_command attribute
    attrs = {
              'attrs' =>
                {
                  'check_command' => 'hostalive',
                  'address' => "#{address}",
                  'display_name' => "#{display_name}",
                  'vars' => tags
                }
            }

    puts "Icinga 2: Creating host '#{name}' with attributes: '" + attrs.to_json + "'."

    begin
      response = rest_client.put(attrs.to_json, headers)
    rescue => e
      e.response
      puts e
    end
    return response
  end

  # update, POST
  def update_host(name, address, display_name, tags)
    api_url = @@api_url_base + @@api_url_obj_hosts + "/#{name}"
    rest_client = prepare_rest_client(api_url)
    headers = {"Content-Type" => "application/json", "Accept" => "application/json"}
    attrs = {
              'attrs' =>
                {
                  'check_command' => 'hostalive',
                  'address' => "#{address}",
                  'display_name' => "#{display_name}",
                  'vars' => tags
                }
            }

    puts "Icinga 2: Updating host '#{name}' with attributes: '" + attrs.to_json + "'."

    begin
      response = rest_client.post(attrs.to_json, headers)
    rescue => e
      puts e
      e.response
    end
    return response

  end

  # delete, DELETE
  def delete_host(name)
    api_url = @@api_url_base + @@api_url_obj_hosts + "/#{name}?cascade=1" #applied services require cascading delete
    rest_client = prepare_rest_client(api_url)
    headers = {"Content-Type" => "application/json", "Accept" => "application/json"}

    puts "Icinga 2: Deleting host '#{name}'."

    begin
      response = rest_client.delete(headers)
    rescue => e
      e.response
      # silently ignore errors with non-existing objects
      #puts "Errors deleting host '#{name}'."
    end

    # we use cascading delete, but anyways
    if response && response.code != 200
      puts response.body
    end

    return response

  end
end



if __FILE__ ==$0
  aws = AwsInstanceManager.new
  i2 = Icinga2InstanceManager.new

  #i2.set_node_name("icinga2a")
  i2.set_api_username("root")
  i2.set_api_password("icinga")

  aws.manage_instances(i2)
end