module PhusionPassenger::Utils::Download

Public Class Methods

included(klass) click to toggle source
# File lib/phusion_passenger/utils/download.rb, line 34
def self.included(klass)
        # When included into another class, make sure that Utils
        # methods are made private.
        public_instance_methods(false).each do |method_name|
                klass.send(:private, method_name)
        end
end

Public Instance Methods

download(url, output, options = {}) click to toggle source

Downloads a file from the given URL and saves it to the given filename. Returns whether the download succeeded.

Options:

show_progress: whether to show download progress. Default: false.
logger: the logger to use. If not given, this function will log to STDERR.
cacert: a CA certificate file to use for verifying SSL websites.
        The default is to use the download tool's down CA database.
use_cache: Whether to copy the file from the download cache, if available.
           Default: false.
connect_timeout: The maximum amount of time to spend on DNS lookup
                 and establishing the TCP connection. Set to nil to
                 disable this timeout. Default: 4.
idle_timeout: The maximum idle read time. Set to nil to set this timeout
              to the default wget value, 900. Set to nil to disable this
              timeout. Default: 5.
total_timeout: The maximum amount of time spent on the whole download
               operation, including connection time. Only has effect on curl.
               Set to nil to disable this timeout. Default: nil.
# File lib/phusion_passenger/utils/download.rb, line 62
def download(url, output, options = {})
        options = {
                :connect_timeout => 4,
                :idle_timeout    => 5
        }.merge(options)
        logger = options[:logger] || Logger.new(STDERR)

        if options[:use_cache] && cache_dir = PhusionPassenger.download_cache_dir
                basename = basename_from_url(url)
                if File.exist?("#{cache_dir}/#{basename}")
                        logger.info "Copying #{basename} from #{cache_dir}..."
                        FileUtils.cp("#{cache_dir}/#{basename}", output)
                        return true
                end
        end

        if PlatformInfo.find_command("curl")
                return download_with_curl(logger, url, output, options)
        elsif PlatformInfo.find_command("wget")
                return download_with_wget(logger, url, output, options)
        else
                logger.error "Could not download #{url}: no download tool found (curl or wget required)"
                return false
        end
end

Private Instance Methods

basename_from_url(url) click to toggle source
# File lib/phusion_passenger/utils/download.rb, line 89
def basename_from_url(url)
        return url.sub(/.*\//, '')
end
download_with_curl(logger, url, output, options) click to toggle source
# File lib/phusion_passenger/utils/download.rb, line 93
def download_with_curl(logger, url, output, options)
        command = ["curl", "-f", "-L", "-o", output]
        if options[:show_progress]
                command << "-#"
        else
                command << "-s"
                command << "-S"
        end
        if options[:cacert]
                command << "--cacert"
                command << options[:cacert]
        end
        if options[:connect_timeout]
                command << "--connect-timeout"
                command << options[:connect_timeout].to_s
        end
        if options[:idle_timeout]
                command << "--speed-time"
                command << options[:idle_timeout].to_s
                command << "--speed-limit"
                command << "1"
        end
        if options[:total_timeout]
                command << "--max-time"
                command << options[:total_timeout].to_s
        end
        command << url
        command_str = Shellwords.join(command)
        logger.info("Invoking: #{command_str}")

        if options[:show_progress]
                # If curl errors out we don't want it to display 'curl: ' prefixes,
                # so we parse its output.
                begin
                        io = IO.popen("#{command_str} 2>&1", "r")
                rescue SystemCallError => e
                        logger.error("Could not invoke curl: #{e}")
                        return false
                end
                begin
                        non_empty_line_encountered = false
                        while !io.eof?
                                # We split on "\r" because progress bar lines do not contain "\n".
                                data = io.gets("\r")
                                data = remove_curl_output_prefix(data)

                                # If an error occurs then the first few lines may be empty.
                                # Skip those.
                                if !non_empty_line_encountered && data =~ /\A\n+/
                                        data.gsub!(/\A\n+/, '')
                                end

                                non_empty_line_encountered = true
                                STDERR.write(data)
                                STDERR.flush
                        end
                ensure
                        io.close
                end
                result = $?.exitstatus == 0
        else
                begin
                        output = %x#{command_str} 2>&1`
                rescue SystemCallError => e
                        logger.error("Could not invoke curl: #{e}")
                        return false
                end
                result = $?.exitstatus == 0
                if !result
                        output = remove_curl_output_prefix(output)
                        output.chomp!
                        logger.error("Could not download #{url}: #{output}")
                end
        end

        return result
end
download_with_wget(logger, url, output, options) click to toggle source
# File lib/phusion_passenger/utils/download.rb, line 175
def download_with_wget(logger, url, output, options)
        command = ["wget", "--tries=1", "-O", output]
        if !options[:show_progress]
                command << "-nv"
        end
        if options[:cacert]
                command << "--ca-certificate=#{options[:cacert]}"
        end
        if options[:connect_timeout]
                command << "--dns-timeout=#{options[:connect_timeout]}"
                command << "--connect-timeout=#{options[:connect_timeout]}"
        end
        if options[:idle_timeout]
                command << "--timeout=#{options[:idle_timeout]}"
        end
        command << url
        command_str = Shellwords.join(command)
        logger.info("Invoking: #{command_str}")

        if options[:show_progress]
                begin
                        result = system(*command)
                rescue SystemCallError => e
                        logger.error("Could not invoke wget: #{e}")
                        return false
                end
                if !result
                        logger.error("Could not download #{url}: #{output}")
                end
        else
                begin
                        output = %x#{command_str} 2>&1`
                rescue SystemCallError => e
                        logger.error("Could not invoke wget: #{e}")
                        return false
                end
                result = $?.exitstatus == 0
                if !result
                        # Error output may begin with "<URL>:\n" which is redundant.
                        output.gsub!(/\A#{Regexp.escape url}:\n/, '')
                        output.chomp!
                        logger.error("Could not download #{url}: #{output}")
                end
        end

        return result
end
remove_curl_output_prefix(line) click to toggle source
# File lib/phusion_passenger/utils/download.rb, line 171
def remove_curl_output_prefix(line)
        return line.gsub(/^curl: (\([0-9]+\) )?/, '')
end