Class: CloudnAPI::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/cloudn-api/client.rb

Overview

In the Client class, there is camel-cased methods such as queryAsyncJobResult. Usually ruby methods are named along with snake-case, but this class needs to handle Cloudstack methods with Ruby’s meta method : method_missing. So if you find camel-cased methods, you can think of that as calling Cloudstack method internally.

Constant Summary collapse

API_LIST_PATH = 
'../api.json'
SLEEP_TIME_SEC = 
5
RETRY_COUNT =

wait for max 30 minutes

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ASYNC_QUERY_FINISHED = 
1
ASYNC_QUERY_ERROR = 
2

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config_file = nil) ⇒ Client

Returns a new instance of Client.



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# File 'lib/cloudn-api/client.rb', line 26

def initialize(config_file = nil)
  setup_logger_and_configs config_file

  @api_key = @config_hash[:api_key].freeze
  @secret_key = @config_hash[:secret_key].freeze
  @url = URI.parse(@config_hash[:url]).freeze
  @wait_async = true
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args) ⇒ Object

to handle CloudStack methods described in

http://cloudstack.apache.org/docs/api/apidocs-4.0.0/TOC_User.html

Note that I didn’t test all methods,so some methods wouldn’t work properly.



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# File 'lib/cloudn-api/client.rb', line 38

def method_missing(method, *args)
  super unless @api_list.include? method.to_s
  hash_response = args ? request_api(method, args.pop) : request_api(method)
  @logger.info hash_response

  if @wait_async and hash_response.values.pop.has_key? 'jobid'
    result = wait_for_async_job(hash_response.values.pop.fetch('jobid'))
    result = result['queryasyncjobresultresponse']
  else
    result = hash_response
  end
  @logger.debug(result)
  result
end

Instance Attribute Details

#api_key ⇒ Object (readonly)

Returns the value of attribute api_key.



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# File 'lib/cloudn-api/client.rb', line 24

def api_key
  @api_key
end

#api_list ⇒ Object (readonly)

Returns the value of attribute api_list.



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# File 'lib/cloudn-api/client.rb', line 24

def api_list
  @api_list
end

#secret_key ⇒ Object (readonly)

Returns the value of attribute secret_key.



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# File 'lib/cloudn-api/client.rb', line 24

def secret_key
  @secret_key
end

#url ⇒ Object (readonly)

Returns the value of attribute url.



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# File 'lib/cloudn-api/client.rb', line 24

def url
  @url
end

#wait_async ⇒ Object (readonly)

Returns the value of attribute wait_async.



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# File 'lib/cloudn-api/client.rb', line 24

def wait_async
  @wait_async
end

Instance Method Details

#build_query_str(hash_cloudn_api) ⇒ Object

Build query string such as

command=...&response=json&apiKey=...&signature=...

Parameters:

  • hash_cloudn_api (Hash) —

    hash of commands for cloudstack API



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# File 'lib/cloudn-api/client.rb', line 142

def build_query_str(hash_cloudn_api)
  # Prepare to create signature and query string.
  hash_cloudn_api_with_key = hash_cloudn_api.merge({:response => :json, :apikey => @api_key})

  # Create signature
  encoded_str = encode(hash_cloudn_api_with_key)
  signature = create_signature encoded_str

  # Create query string with signature
  initial_str = hash_cloudn_api_with_key.flat_map {|k, v| "#{k}=#{ERB::Util.url_encode(v.to_s)}" }.join('&')
  query_string = initial_str + "&signature=#{signature}"
end

#configure_logger ⇒ Object

Set up logger instance



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# File 'lib/cloudn-api/client.rb', line 97

def configure_logger
  @logger.progname = 'CloudnAPI'
  @logger.datetime_format = "%Y-%m-%d %H:%M:%S "
  log_level = @config_hash[:log_level] || :error
  @logger.level =
      case log_level.to_sym
        when :info
          Logger::INFO
        when :debug
          Logger::DEBUG
        when :warn
          Logger::WARN
        when :error
          Logger::ERROR
        when :fatal
          Logger::FATAL
        else
          Logger::INFO
      end
end

#create_signature(concatenated_str) ⇒ Object

Create signature: Create HMAC with secret key, encode HMAC with Base64, and url-encode it



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# File 'lib/cloudn-api/client.rb', line 156

def create_signature(concatenated_str)
  hmac = OpenSSL::HMAC::digest(::OpenSSL::Digest::SHA1.new, @secret_key, concatenated_str)
  base64 = Base64.encode64(hmac).chomp
  ERB::Util.url_encode(base64)
end

#encode(param_hash) ⇒ Object

Return url encoded string. Note: only values are url encoded.



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# File 'lib/cloudn-api/client.rb', line 163

def encode(param_hash)
  encoded_hash = param_hash.each_with_object({}) { |(k, v), new_hash|
    new_hash[k] = ERB::Util.url_encode(v.to_s).downcase
  }
  sorted_hash = Hash[encoded_hash.sort]
  concatnated_str = sorted_hash.flat_map {|k, v| "#{k}=#{v}" }.join('&')
end

#load_api_list ⇒ Object 



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# File 'lib/cloudn-api/client.rb', line 171

def load_api_list
  api_list_path = File.expand_path(API_LIST_PATH, __FILE__)
  list = open(api_list_path).read
  @api_list = JSON.parse(list)
end

#load_config(config_file) ⇒ Object

Load configuration to @config_hash as follows

1. Check config_jfile which is explicitly specified
2. Check default location, ~/.cloudnapi/config
3. Check environmental variables

If none of them can’t be found, then report errors and exit.



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# File 'lib/cloudn-api/client.rb', line 182

def load_config(config_file)

  # If config file is not specified, check default location
  config_file = search_config_file unless config_file

  # If there are ENV variables, then use them and return from this method.
  # If none of them, configuration or Env variables, specified,
  # then report error and exit.
  unless config_file
    if ENV['CLOUDN_API_KEY'] and ENV['CLOUDN_SECRET_KEY'] and ENV['CLOUDN_URL']
      @config_hash = {}
      @config_hash[:api_key] = ENV['CLOUDN_API_KEY']
      @config_hash[:secret_key] = ENV['CLOUDN_SECRET_KEY']
      @config_hash[:url] = ENV['CLOUDN_URL']
      return
    else
      @logger.error("Couldn't find no configuration file.")
      @logger.error('~/.cloudnapi/config or specify config file.')
      exit 1
    end
  end

  # Read and load @config_hash from config_file
  config_body = open(config_file).read
  begin
    @config_hash = JSON.parse(config_body, {:symbolize_names => true})
  rescue Exception => e
    @logger.error("#{config_file} seems broken. Please check that ...")
    @logger.error e
    exit 1
  end
end

#queryAsyncJobResult(jobid) ⇒ Object

This method is only explicitly defined method for Cloudstack in order to prevent infinite loop of method_missing.



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# File 'lib/cloudn-api/client.rb', line 79

def queryAsyncJobResult(jobid)
  @logger.info "Requesting :queryAsyncJobResult - jobid=#{jobid}"
  request_api(:queryAsyncJobResult, {jobid: jobid})
end

#request(query_string) ⇒ Object

Issue HTTP request to API end point (url)



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# File 'lib/cloudn-api/client.rb', line 119

def request(query_string)
  url = @url.dup
  url.query = query_string

  begin
    response_text = OpenURI.open_uri(
        url,
        :ssl_verify_mode => OpenSSL::SSL::VERIFY_NONE,
        'User-Agent' => "CloudnAPI/#{RUBY_VERSION}"
    ).read
  rescue OpenURI::HTTPError => ex
    @logger.error url
    @logger.error ex
  rescue Exception => ex
    @logger.error url
    @logger.error ex
  end
  parsed_reponse = JSON.parse(response_text)
end

#request_api(method, args = nil) ⇒ Object

build query string, then issue http request to Cloudn end point



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# File 'lib/cloudn-api/client.rb', line 85

def request_api(method, args=nil)
  if args
    hash_cloudn_api = args.merge({ command: method.to_s })
    query_str = build_query_str hash_cloudn_api
  else
    query_str = build_query_str({ command:  method.to_s })
  end
  @logger.info "#{method} - #{@config_hash[:url]}?#{query_str}"
  request query_str
end

#search_config_file ⇒ String

Find config file from HOME/.kneadn/config

Returns:

  • (String) —

    path of config file



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# File 'lib/cloudn-api/client.rb', line 217

def search_config_file
  default_config_path = ENV['HOME'] + '/.cloudnapi/config'
  File.exists?(default_config_path) ? default_config_path : nil
end

#setup_logger_and_configs(config_file) ⇒ Object 



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# File 'lib/cloudn-api/client.rb', line 53

def setup_logger_and_configs(config_file)
  @logger = Logger.new(STDOUT)
  load_config config_file
  load_api_list
  configure_logger
end

#wait_for_async_job(jobid) ⇒ Object

Wait until async job is finished



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# File 'lib/cloudn-api/client.rb', line 61

def wait_for_async_job(jobid)
  RETRY_COUNT.times {
    result = queryAsyncJobResult(jobid)

    # When async job has finished, let's escape from loop
    if result['queryasyncjobresultresponse']['jobstatus'] == ASYNC_QUERY_FINISHED
      # @logger.info result
      break result
    elsif result['queryasyncjobresultresponse']['jobstatus'] == ASYNC_QUERY_ERROR
      @logger.error result
      raise StandardError.new('Error occurred')
    end
    sleep SLEEP_TIME_SEC
  }
end