doctor.rb

# Usage: ruby doctor.rb [HOST=status.github.com[:PORT=443]]
require 'rbconfig'
require 'net/https'

if ARGV[0] =~ /^[^-]/
  host, port = ARGV[0].split(':', 2)
else
  host = 'status.github.com'
end
port ||= 443

ruby = File.join(RbConfig::CONFIG['bindir'], RbConfig::CONFIG['ruby_install_name'])
ruby_version = RUBY_VERSION
if patch = RbConfig::CONFIG['PATCHLEVEL']
  ruby_version += "-p#{patch}"
end
puts "%s (%s)" % [ruby, ruby_version]

openssl_dir = OpenSSL::X509::DEFAULT_CERT_AREA
mac_openssl = '/System/Library/OpenSSL' == openssl_dir
puts "%s: %s" % [OpenSSL::OPENSSL_VERSION, openssl_dir]
[OpenSSL::X509::DEFAULT_CERT_DIR_ENV, OpenSSL::X509::DEFAULT_CERT_FILE_ENV].each do |key|
  puts "%s=%s" % [key, ENV[key].to_s.inspect]
end

ca_file = ENV[OpenSSL::X509::DEFAULT_CERT_FILE_ENV] || OpenSSL::X509::DEFAULT_CERT_FILE
ca_path = (ENV[OpenSSL::X509::DEFAULT_CERT_DIR_ENV] || OpenSSL::X509::DEFAULT_CERT_DIR).chomp('/')

puts "\nHEAD https://#{host}:#{port}"
http = Net::HTTP.new(host, port)
http.use_ssl = true

# Explicitly setting cert_store like this is not needed in most cases but it
# seems necessary in edge cases such as when using `verify_callback` in some
# combination of Ruby + OpenSSL versions.
http.cert_store = OpenSSL::X509::Store.new
http.cert_store.set_default_paths

http.verify_mode = OpenSSL::SSL::VERIFY_PEER
failed_cert = failed_cert_reason = nil

if mac_openssl
  warn "warning: will not be able show failed certificate info on OS X's OpenSSL"
  # This drives me absolutely nuts. It seems that on Rubies compiled against OS X's
  # system OpenSSL, the mere fact of defining a `verify_callback` makes the
  # cert verification fail for requests that would otherwise be successful.
else
  http.verify_callback = lambda { |verify_ok, store_context|
    if !verify_ok
      failed_cert = store_context.current_cert
      failed_cert_reason = "%d: %s" % [ store_context.error, store_context.error_string ]
    end
    verify_ok
  }
end

user_agent = "net/http #{ruby_version}"
req = Net::HTTP::Head.new('/', 'user-agent' => user_agent)

begin
  res = http.start { http.request(req) }
  abort res.inspect if res.code.to_i >= 500
  puts "OK"
rescue Errno::ECONNREFUSED
  puts "Error: connection refused"
  exit 1
rescue OpenSSL::SSL::SSLError => e
  puts "#{e.class}: #{e.message}"

  if failed_cert
    puts "\nThe server presented a certificate that could not be verified:"
    puts "  subject: #{failed_cert.subject}"
    puts "  issuer: #{failed_cert.issuer}"
    puts "  error code %s" % failed_cert_reason
  end

  ca_file_missing = !File.exist?(ca_file) && !mac_openssl
  ca_path_empty = Dir["#{ca_path}/*"].empty?

  if ca_file_missing || ca_path_empty
    puts "\nPossible causes:"
    puts "  `%s' does not exist" % ca_file if ca_file_missing
    puts "  `%s/' is empty" % ca_path if ca_path_empty
  end

  exit 1
end