lib/t2-server/net/connection.rb
# Copyright (c) 2010-2013 The University of Manchester, UK.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# * Neither the names of The University of Manchester nor the names of its
# contributors may be used to endorse or promote products derived from this
# software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# Author: Robert Haines
require 'uri'
require 'net/http/persistent'
module T2Server
# This is a factory for connections to a Taverna Server. It will return
# either a http or https connection depending on what sort of uri is passed
# into it. This class maintains a list of connections that it knows about
# and will return an already established connection if it can.
class ConnectionFactory
private_class_method :new
# list of connections we know about
@@connections = []
# :call-seq:
# ConnectionFactory.connect(uri) -> Connection
#
# Connect to a Taverna Server instance and return either a
# T2Server::HttpConnection or T2Server::HttpsConnection object to
# represent it.
def ConnectionFactory.connect(uri, params = nil)
# we want to use URIs here
if !uri.is_a? URI
raise URI::InvalidURIError.new
end
# if we're given params they must be of the right type
if !params.nil? && !params.is_a?(ConnectionParameters)
raise ArgumentError, "Parameters must be ConnectionParameters", caller
end
# see if we've already got this connection
conn = @@connections.find {|c| c.uri == uri}
if !conn
if uri.scheme == "http"
conn = HttpConnection.new(uri, params)
elsif uri.scheme == "https"
conn = HttpsConnection.new(uri, params)
else
raise URI::InvalidURIError.new
end
@@connections << conn
end
conn
end
end
# A class representing a http connection to a Taverna Server. This class
# should only ever be created via the T2Server::Connection factory class.
class HttpConnection
# The URI of this connection instance.
attr_reader :uri
# Open a http connection to the Taverna Server at the uri supplied.
def initialize(uri, params = nil)
@uri = uri
@params = params || DefaultConnectionParameters.new
# Open a persistent HTTP connection.
@http = Net::HTTP::Persistent.new("Taverna_Server_Ruby_Client")
# Set timeouts if specified.
@http.open_timeout = @params[:open_timeout] if @params[:open_timeout]
@http.read_timeout = @params[:read_timeout] if @params[:read_timeout]
end
# :call-seq:
# GET(uri, type, range, credentials) -> string
#
# HTTP GET a resource at _uri_ of _type_ from the server. If successful
# the body of the response is returned. A portion of the data can be
# retrieved by specifying a byte range, start..end, with the _range_
# parameter.
def GET(uri, type, range, credentials, &block)
get = Net::HTTP::Get.new(uri.path)
get["Accept"] = type
get["Range"] = "bytes=#{range.min}-#{range.max}" unless range.nil?
response = submit(get, uri, credentials, &block)
case response
when Net::HTTPOK, Net::HTTPPartialContent
return response.body
when Net::HTTPNoContent
return nil
when Net::HTTPMovedTemporarily
new_conn = redirect(response["location"])
raise ConnectionRedirectError.new(new_conn)
else
report_error("GET", uri.path, response, credentials)
end
end
# :call-seq:
# PUT(uri, value, type, credentials) -> true or false
# PUT(uri, value, type, credentials) -> URI
# PUT(uri, stream, type, credentials) -> URI
#
# Upload data via HTTP PUT. Data may be specified as a value or as a
# stream. The stream can be any object that has a read(length) method;
# instances of File or IO, for example.
#
# If successful _true_ or a URI to the uploaded resource is returned
# depending on whether the operation has altered a parameter (true) or
# uploaded new data (URI).
def PUT(uri, data, type, credentials)
put = Net::HTTP::Put.new(uri.path)
put.content_type = type
set_upload_body(put, data)
response = submit(put, uri, credentials)
case response
when Net::HTTPOK, Net::HTTPAccepted
# We've either set a parameter or started a run so we get 200 or 202
# back from the server, respectively. Return true to indicate success.
true
when Net::HTTPCreated
# We've uploaded data so we get 201 back from the server. Return the
# uri of the created resource.
URI.parse(response['location'])
when Net::HTTPNoContent
# We've modified data so we get 204 back from the server. Return the
# uri of the modified resource.
uri
when Net::HTTPServiceUnavailable
raise ServerAtCapacityError.new
else
report_error("PUT", uri.path, response, credentials)
end
end
# :call-seq:
# POST(uri, value, type, credentials) -> URI
# POST(uri, stream, type, credentials) -> URI
#
# Upload data via HTTP POST. Data may be specified as a value or as a
# stream. The stream can be any object that has a read(length) method;
# instances of File or IO, for example.
#
# If successful the URI of the uploaded resource is returned.
def POST(uri, data, type, credentials)
post = Net::HTTP::Post.new(uri.path)
post.content_type = type
set_upload_body(post, data)
response = submit(post, uri, credentials)
case response
when Net::HTTPCreated
# return the URI of the newly created item
URI.parse(response['location'])
when Net::HTTPServiceUnavailable
raise ServerAtCapacityError.new
else
report_error("POST", uri.path, response, credentials)
end
end
# :call-seq:
# DELETE(uri, credentials) -> true or false
#
# Perform an HTTP DELETE on a _uri_ on the server. If successful true
# is returned.
def DELETE(uri, credentials)
delete = Net::HTTP::Delete.new(uri.path)
response = submit(delete, uri, credentials)
case response
when Net::HTTPNoContent
# Success, carry on...
true
else
report_error("DELETE", uri.path, response, credentials)
end
end
# :call-seq:
# OPTIONS(uri, credentials) -> hash
#
# Perform the HTTP OPTIONS command on the given _uri_ and return a hash
# of the headers returned.
def OPTIONS(uri, credentials)
options = Net::HTTP::Options.new(uri.path)
response = submit(options, uri, credentials)
case response
when Net::HTTPOK
response.to_hash
else
report_error("OPTIONS", uri.path, response, credentials)
end
end
private
# If one of the expected responses for a HTTP method is not received then
# handle the error condition here.
def report_error(method, path, response, credentials)
case response
when Net::HTTPNotFound
raise AttributeNotFoundError.new(path)
when Net::HTTPForbidden
raise AccessForbiddenError.new("resource #{path}")
when Net::HTTPUnauthorized
raise AuthorizationError.new(credentials)
else
raise UnexpectedServerResponse.new(method, path, response)
end
end
# If we have a stream then we need to set body_stream and then either
# supply a content length or set the transfer encoding to "chunked". A
# file object can supply its size, a bare IO object cannot. If we have a
# simple value we can set body directly.
def set_upload_body(request, data)
if data.respond_to? :read
request.body_stream = data
if data.respond_to? :size
request.content_length = data.size
else
request["Transfer-encoding"] = "chunked"
end
else
request.body = data
end
end
# If a block is passed in here then the response is returned in chunks
# (streamed). If no block is passed in the whole response is read into
# memory and returned.
def submit(request, uri, credentials, &block)
credentials.authenticate(request) unless credentials.nil?
response = nil
begin
@http.request(uri, request) do |r|
r.read_body(&block)
response = r
end
response
rescue InternalHTTPError => e
raise ConnectionError.new(e)
end
end
def redirect(location)
uri = URI.parse(location)
new_uri = URI::HTTP.new(uri.scheme, nil, uri.host, uri.port, nil,
@uri.path, nil, nil, nil);
ConnectionFactory.connect(new_uri, @params)
end
end
# A class representing a https connection to a Taverna Server. This class
# should only ever be created via the T2Server::Connection factory class.
class HttpsConnection < HttpConnection
# Open a https connection to the Taverna Server at the uri supplied.
def initialize(uri, params = nil)
super(uri, params)
if OpenSSL::SSL::SSLContext::METHODS.include? @params[:ssl_version]
@http.ssl_version = @params[:ssl_version]
end
set_peer_verification
set_client_authentication
end
private
def set_peer_verification
if @params[:verify_peer]
if @params[:ca_file]
@http.ca_file = @params[:ca_file]
end
if @params[:ca_path]
store = OpenSSL::X509::Store.new
store.set_default_paths
if @params[:ca_path].is_a? Array
@params[:ca_path].each { |path| store.add_path(path) }
else
store.add_path(@params[:ca_path])
end
@http.cert_store = store
end
@http.verify_mode = OpenSSL::SSL::VERIFY_PEER
else
@http.verify_mode = OpenSSL::SSL::VERIFY_NONE
end
end
def set_client_authentication
if @params[:client_certificate]
cert = File.read(@params[:client_certificate])
pkcs12 = OpenSSL::PKCS12.new(cert, @params[:client_password])
@http.certificate = pkcs12.certificate
@http.private_key = pkcs12.key
end
end
end
end