require 'webrick'
require 'json'
require 'net/http'
require 'rhcp/broker'
require 'rhcp/request'
require 'rhcp/rhcp_exception'
include WEBrick
module RHCP
# TODO add some logging
# The +HttpExporter+ connects to the RHCP::Broker and exports all commands
# registered there via http, i.e. it servers requests to the URLs
#
# /rhcp/get_commands
# /rhcp/get_lookup_values
# /rhcp/execute
#
# All data is transferred in JSON format.
class HttpExporter
DEFAULT_PORT = 42000
DEFAULT_PREFIX = "rhcp"
# by default, a new HttpExporter will create it's own +HTTPServer+
# on port 42000 - if you want to change this port, you can pass the port
# to use as +port+ option. If you want to use an existing +HTTPServer+
# instance, you can pass it as +server+ option instead.
#
# Also, you can specify the prefix for the rhcp URLs using the +prefix+
# option - otherwise, all
# rhcp actions will be exported at
# /rhcp/get_commands
# /rhcp/get_lookup_values
# /rhcp/execute
# If you change this, please be aware that all clients that want to connect
# to this server need to be configured accordingly.
def initialize(broker, options = Hash.new())
@logger = RHCP::ModuleHelper::instance.logger
@broker = broker
# build your own server or use the one passed in as param
port = options.has_key?(:port) ? options[:port] : DEFAULT_PORT
if options.has_key?(:server)
@server = options[:server]
@logger.debug("using existing server #{@server}")
else
@logger.debug("opening own server on port #{port}")
@server = HTTPServer.new( :Port => port )
end
@url_prefix = options.has_key?(:prefix) ? options[:prefix] : DEFAULT_PREFIX
@server.mount_proc("/#{@url_prefix}/") {|req, res|
res.body = "<HTML>hello (again)</HTML>"
res['Content-Type'] = "text/html"
}
# TODO this path should probably be quite relative
@server.mount "/#{@url_prefix}/info", HTTPServlet::FileHandler, "docroot"
@server.mount "/#{@url_prefix}/info2", HTTPServlet::FileHandler, "qooxdoo_rhcp/build"
@server.mount "/#{@url_prefix}/get_commands", GetCommandsServlet, @broker
@server.mount "/#{@url_prefix}/get_lookup_values", GetLookupValuesServlet, @broker
@server.mount "/#{@url_prefix}/execute", ExecuteServlet, @broker
@logger.info("http exporter has been initialized - once started, it will listen on port '#{port}' for URLs starting with prefix '#{@url_prefix}'")
end
class BaseServlet < HTTPServlet::AbstractServlet
def initialize(server, broker)
super(server)
@broker = broker
end
def do_GET(req, res)
res['Content-Type'] = "application/json"
begin
#@logger.info("executing #{req}")
do_it(req, res)
#@logger.info("finished executing #{req}")
rescue RHCP::RhcpException => ex
# TODO define error format (should we send back a JSON-ified response object here?)
@logger.error("got an exception while executing request . #{ex}")
res.status = 500
res.body = [ ex.to_s ].to_json()
#puts ex
#puts ex.backtrace.join("\n")
end
end
# TODO is this a good idea?
def do_POST(req, res)
do_GET(req, res)
end
end
class GetCommandsServlet < BaseServlet
def do_it(req, res)
commands = @broker.get_command_list
puts "about to send back commands : #{commands.values.to_json()}"
res.body = commands.values.to_json()
end
end
class GetLookupValuesServlet < BaseServlet
def do_it(req, res)
partial_value = req.query.has_key?('partial') ? req.query['partial'] : ''
command = @broker.get_command(req.query['command'])
param = command.get_param(req.query['param'])
lookup_values = param.get_lookup_values(partial_value)
res.body = lookup_values.to_json()
end
end
class ExecuteServlet < BaseServlet
def do_it(req, res)
@logger.info("got an execute request : #{req}")
# TODO filter "nocache" parameters from query string
request = RHCP::Request.reconstruct_from_json(@broker, req.body)
response = request.execute()
@logger.debug("sending back response : #{response.to_json()}")
res.body = response.to_json()
end
end
def run
@server.start
end
def start
puts "about to start server..."
@thread = Thread.new {
puts "in thread; starting server..."
@server.start
puts "in thread: continuing..."
}
end
def stop
puts "about to stop server"
@server.stop
puts "thread stopped"
# TODO wait until after the server has ended - when this method exits, the server is still shutting down
end
end
end