Module: Kafka::CLI

Extended by:
CLI
Included in:
CLI
Defined in:
lib/kafka/cli.rb

Overview

:nodoc: all

Instance Method Summary collapse

Instance Method Details

#config ⇒ Object 



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# File 'lib/kafka/cli.rb', line 67

def config
  @config ||= {:compression => string_to_compression("no")}
end

#help ⇒ Object 



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# File 'lib/kafka/cli.rb', line 71

def help
  option_parser.to_s
end

#option_parser ⇒ Object 



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# File 'lib/kafka/cli.rb', line 75

def option_parser
  OptionParser.new do |opts|
    opts.banner = "Usage: #{program_name} [options]"
    opts.separator ""

    opts.on("-h","--host HOST", "Set the kafka hostname") do |h|
      config[:host] = h
    end

    opts.on("-p", "--port PORT", "Set the kafka port") do |port|
      config[:port] = port.to_i
    end

    opts.on("-t", "--topic TOPIC", "Set the kafka topic") do |topic|
      config[:topic] = topic
    end

    opts.on("-c", "--compression no|gzip|snappy", "Set the compression method") do |meth|
      config[:compression] = string_to_compression(meth)
    end if publish?

    opts.on("-m","--message MESSAGE", "Message to send") do |msg|
      config[:message] = msg
    end if publish?

    opts.separator ""

    opts.on("--help", "show the help") do
      config[:help] = true
    end

    opts.separator ""
    opts.separator "You can set the host, port, topic and compression from the environment variables: KAFKA_HOST, KAFKA_PORT, KAFKA_TOPIC AND KAFKA_COMPRESSION"
  end
end

#parse_args(args = ARGV) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 56

def parse_args(args = ARGV)
  option_parser.parse(args)
end

#program_name(pn = $0) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 119

def program_name(pn = $0)
  File.basename(pn)
end

#publish(options) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 136

def publish(options)
  trap(:INT){ exit }
  producer = Producer.new(options)
  loop do
    publish_loop(producer)
  end
end

#publish! ⇒ Object 



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# File 'lib/kafka/cli.rb', line 22

def publish!
  read_env
  parse_args
  validate_config
  if config[:message]
    push(config, config.delete(:message))
  else
    publish(config)
  end
end

#publish? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kafka/cli.rb', line 111

def publish?
  program_name == "kafka-publish"
end

#publish_loop(producer) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 144

def publish_loop(producer)
  message = read_input
  producer.push(Message.new(message))
end

#push(options, message) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 132

def push(options, message)
  Producer.new(options).push(Message.new(message))
end

#read_env(env = ENV) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 60

def read_env(env = ENV)
  config[:host] = env["KAFKA_HOST"] if env["KAFKA_HOST"]
  config[:port] = env["KAFKA_PORT"].to_i if env["KAFKA_PORT"]
  config[:topic] = env["KAFKA_TOPIC"] if env["KAFKA_TOPIC"]
  config[:compression] = string_to_compression(env["KAFKA_COMPRESSION"]) if env["KAFKA_COMPRESSION"]
end

#read_input ⇒ Object 



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# File 'lib/kafka/cli.rb', line 149

def read_input
  input = $stdin.gets
  if input
    input.strip
  else
    exit # gets return nil when eof
  end

end

#string_to_compression(meth) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 123

def string_to_compression(meth)
  case meth
  when "no" then Message::NO_COMPRESSION
  when "gzip" then Message::GZIP_COMPRESSION
  when "snappy" then Message::SNAPPY_COMPRESSION
  else raise "No supported compression"
  end
end

#subscribe(options) ⇒ Object 



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# File 'lib/kafka/cli.rb', line 159

def subscribe(options)
  trap(:INT){ exit }
  consumer = Consumer.new(options)
  consumer.loop do |messages|
    messages.each do |message|
      puts message.payload
    end
  end
end

#subscribe! ⇒ Object 



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# File 'lib/kafka/cli.rb', line 34

def subscribe!
  read_env
  parse_args
  validate_config
  subscribe(config)
end

#subscribe? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kafka/cli.rb', line 115

def subscribe?
  program_name == "kafka-subscribe"
end

#validate_config ⇒ Object 



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# File 'lib/kafka/cli.rb', line 41

def validate_config
  if config[:help]
    puts help
    exit
  end
  config[:host] ||= IO::HOST
  config[:port] ||= IO::PORT
  config[:topic].is_a?(String) or raise "Missing topic"

rescue RuntimeError => e
  puts e.message
  puts help
  exit
end