module R10K::Util::Downloader

Utility mixin for classes that need to download files

Constants

CHUNK_SIZE

Public Instance Methods

checksum_algorithm() click to toggle source

Downloader objects need to checksum downloaded or saved content. The algorithm used to perform this checksumming (and therefore the kinds of checksums returned by various methods) is reported by this method.

@return [Symbol] The checksum algorithm the downloader uses

# File lib/r10k/util/downloader.rb, line 15
def checksum_algorithm
  @checksum_algorithm ||= :SHA256
end

Private Instance Methods

checksum_algorithm=(algorithm) click to toggle source

Set the checksum algorithm the downloader should use. It should be a symbol, and a valid Ruby 'digest' library algorithm. The default is :SHA256.

@param algorithm [Symbol] The checksum algorithm the downloader should use

# File lib/r10k/util/downloader.rb, line 26
def checksum_algorithm=(algorithm)
  @checksum_algorithm = algorithm
end

copy(src_file, dst_file) click to toggle source

@param src_file The file or path to copy from @param dst_file The file or path to copy to @return [String] The copied file's sha256 hex digest

# File lib/r10k/util/downloader.rb, line 52
def copy(src_file, dst_file)
  digest = Digest(checksum_algorithm).new
  File.open(src_file, 'rb') do |input_stream|
    File.open(dst_file, 'wb') do |output_stream|
      until input_stream.eof?
        chunk = input_stream.read(CHUNK_SIZE)
        output_stream.write(chunk)
        digest.update(chunk)
      end
    end
  end

  digest.hexdigest
end

download(src_uri, dst_file) click to toggle source

@param src_uri [URI] The URI to download from @param dst_file [String] The file or path to save to @return [String] The downloaded file's hex digest

# File lib/r10k/util/downloader.rb, line 35
def download(src_uri, dst_file)
  digest = Digest(checksum_algorithm).new
  http_get(src_uri) do |resp|
    File.open(dst_file, 'wb') do |output_stream|
      resp.read_body do |chunk|
        output_stream.write(chunk)
        digest.update(chunk)
      end
    end
  end

  digest.hexdigest
end

file_digest(path) click to toggle source

Return the sha256 digest of the file at the given path

@param path [String] The path to the file @return [String] The file's sha256 hex digest

# File lib/r10k/util/downloader.rb, line 114
def file_digest(path)
  File.open(path) do |file|
    reader_digest(file)
  end
end

http_get(uri, redirect_limit: 10, proxy: nil) { |response| ... } click to toggle source

Start a Net::HTTP::Get connection, then yield the Net::HTTPSuccess object to the caller's block. Follow redirects if Net::HTTPRedirection responses are encountered, and use a proxy if directed.

@param uri [URI] The URI to download the file from @param redirect_limit [Integer] How many redirects to permit before failing @param proxy [URI, String] The URI to use as a proxy

# File lib/r10k/util/downloader.rb, line 74
def http_get(uri, redirect_limit: 10, proxy: nil, &block)
  raise "HTTP redirect too deep" if redirect_limit.zero?

  session = Net::HTTP.new(uri.host, uri.port, *proxy_to_array(proxy))
  session.use_ssl = true if uri.scheme == 'https'
  session.start

  begin
    session.request_get(uri) do |response|
      case response
      when Net::HTTPRedirection
        redirect = response['location']
        session.finish
        return http_get(URI.parse(redirect), redirect_limit: redirect_limit - 1, proxy: proxy, &block)
      when Net::HTTPSuccess
        yield response
      else
        raise "Unexpected response code #{response.code}: #{response}"
      end
    end
  ensure
    session.finish if session.active?
  end
end

proxy_to_array(proxy_uri) click to toggle source

Helper method to translate a proxy URI to array arguments for Net::HTTP#new. A nil argument returns nil array elements.

# File lib/r10k/util/downloader.rb, line 101
def proxy_to_array(proxy_uri)
  if proxy_uri
    px = proxy_uri.is_a?(URI) ? proxy_uri : URI.parse(proxy_uri)
    [px.host, px.port, px.user, px.password]
  else
    [nil, nil, nil, nil]
  end
end

reader_digest(reader) click to toggle source

Return the sha256 digest of the readable data

@param reader [String] An object that responds to read @return [String] The read data's sha256 hex digest

# File lib/r10k/util/downloader.rb, line 124
def reader_digest(reader)
  digest = Digest(checksum_algorithm).new
  while chunk = reader.read(CHUNK_SIZE)
    digest.update(chunk)
  end

  digest.hexdigest
end