class Zazu

Fetch tools and run them

Example:

zazu = Zazu.new 'my-script'
zazu.fetch url: 'https://example.com/my_script.sh'
zazu.run ['--environment', 'prod']

Constants

VERSION

Attributes

name[R]
path[R]

Public Class Methods

new(name, logger: Logger.new(STDERR), level: Logger::INFO) click to toggle source

Creates the Zazu instance. Create as many as you like.

  • :name: - The name of the command

  • :logger: - Default to STDERR, can be replaced with another, e.g. IO::NIL

  • :level: - Log level for the logger

# File lib/zazu.rb, line 33
def initialize(name, logger: Logger.new(STDERR), level: Logger::INFO)
  @name = name
  @path = File.join Dir.tmpdir, name + '-download'
  @logger = logger
  @logger.level = level
end

Public Instance Methods

fetch(url: nil, age: 60*60, &block) click to toggle source

Download the tool, to the temp directory. Raises a DownloadError on HTTP error.

  • :url: - The URL to the tool–Optional, can specity the block instead

  • :age: - Seconds old the downloaded copy can be before downloading again–Default is 3600

  • :block: - Receives the OS (:linux, :mac, :windows) and the machine arch (32 or 64)–Should return the URL

# File lib/zazu.rb, line 45
def fetch(url: nil, age: 60*60, &block)
  return false if File.exists?(path) && Time.now - File.stat(path).mtime < age

  url ||= block.call os, arch
  @logger.info "Downloading from #{url}".cyan

  download_file url
end
run(args = [], show: //, hide: /^$/, &block) click to toggle source

Run the downloaded tool with arguments Raises a RunError if the command exits with nonzero.

  • :args: - An array of args for the command

  • :show: - A regexp of output (STDOUT and STDERR) to include

  • :hide: - A regexp of output (STDOUT and STDERR) to exclude

  • :block: - If given, receies each output line, otherwise output is logged

# File lib/zazu.rb, line 61
def run(args = [], show: //, hide: /^$/, &block) 
  command = [path] + args
  @logger.debug "Running command #{command}".yellow
  Open3.popen3 *command do |i,o,e,t|
    i.close

    threads = [o,e].map do |x|
      Thread.new do
        x.each_line do |line|
          line.chomp!
          next if line !~ show || line =~ hide

          if block
            block.call line
          else
            @logger.info line.cyan
          end
        end
      end
    end

    threads.each &:join
    t.join

    raise RunError.new "#{path} exited with code #{t.value}" unless t.value == 0
  end

  true
end

Private Instance Methods

arch() click to toggle source 
# File lib/zazu.rb, line 132
def arch
  Etc.uname[:machine] =~ /x(86_)?64/ ? 64 : 32
end
download_file(url) click to toggle source 
# File lib/zazu.rb, line 93
def download_file(url)
  uri = URI url
  res = Net::HTTP.start uri.host, uri.port, use_ssl: uri.scheme == 'https' do |http|
    http.request Net::HTTP::Get.new uri do |res|
      if res.is_a?(Net::HTTPOK)
        @logger.debug "Opening file #{path}".yellow
        File.open path, 'wb' do |file|
          res.read_body do |chunk|
            file.write chunk
          end
        end
        @logger.debug "Closed file #{path}".yellow
        FileUtils.chmod 0755, path
      end
    end
  end

  case res
  when Net::HTTPOK
    true
  when Net::HTTPRedirection
    @logger.debug "Following redirect #{res['Location']}"
    download_file res['Location']
  else
    raise DownloadError.new "Error downloading #{url}, got #{res}"
  end
end
os() click to toggle source 
# File lib/zazu.rb, line 121
def os
  case Etc.uname[:sysname]
  when /linux/i
    :linux
  when /darwin/i
    :mac
  when /windows/i
    :windows
  end
end