Empty JRuby runtime from JRuby

dubstep · March 31, 2012, 2:39pm

Hello,

is it possible to create empty JRuby environment from JRuby program?

I have experimented with several variants of starting scripting
container,
e.g.

marekjelen/thick/blob/master/lib/thick/loader.rb

module Thick

  class Loader

    include Thick::Java::ServerRubyInterface

    def initialize(options)
      @options = options
      ENV['RACK_ENV'] ||= ENV['RAILS_ENV'] ||= @options[:environment]
      @application = @options[:application] ||= Rack::Builder.parse_file(File.expand_path(@options[:file], @options[:directory]))[0]
    end

    def call(env)
      #noinspection RubyArgCount
      env['rack.input'] = Buffer.new(env['rack.input'])
      env['rack.errors'] = env['rack.errors'].to_io

      status, headers, body = @application.call(env)

      return if env['thick.response_bypass']

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but contants (classes) are surviving among calls

Do you have any idea?

Thanks

–
Marek J.

m: +420 724 255807
e: [email protected]

marek_j · March 31, 2012, 9:53pm

Hello,

On Sat, Mar 31, 2012 at 8:38 AM, Marek J. [email protected] wrote:

Hello,

is it possible to create empty JRuby environment from JRuby program?

I have experimented with several variants of starting scripting container,
e.g.

thick/lib/thick/loader.rb at master · marekjelen/thick · GitHub

but contants (classes) are surviving among calls

Sounds like a singleton type container was instantiated.
What class do you get by:

container.getProvider.class

Btw, it’s very interesting way of using ScriptingContainer.

-Yoko

marek_j · March 31, 2012, 10:44pm

I did something similar a while back – with the purpose of running two
different version of the same Gem in one application.

I tried several different approaches, but here’s basically what I ended
up with:

gist.github.com

https://gist.github.com/jkutner/2268163

boot.rb

$LOAD_PATH << $APP_LOAD_PATH  #set the load path from the APP_LOAD_PATH binding

if $RACK_ENV == 'production'
  ENV['GEM_PATH'] = "#{File.join($RULE_SERVER_HOME, 'vendor/jruby/1.8')}:#{File.join($TORQUEBOX_HOME, 'jruby/lib/ruby/gems/1.8')}"
  ENV['GEM_HOME'] = File.join($RULE_SERVER_HOME, 'vendor/jruby/1.8')
else
  puts 'Using global GEM_HOME directory.'
end

require 'rubygems'

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engine.rb

java_import "javax.script.ScriptContext"
java_import "javax.script.ScriptEngine"
java_import "javax.script.ScriptEngineManager"
java_import "javax.script.ScriptException"
java_import "java.io.FileNotFoundException"
java_import "javax.script.Bindings"
java_import "javax.script.SimpleBindings"
java_import "java.io.FileReader"
java_import "java.io.Reader"

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It’s been so long that I don’t remember much about why I did things the
way I did. But I did not have the problems like you describe.

I did have to watch out for :foo == :foo returning false within the
embedded jruby

marek_j · April 1, 2012, 9:40am

Interesting. Joe, thanks for the gist, it seems to help move a bit
further.
However, I am now getting very weird exception from the application, for
both … your and mine original version.

gist.github.com

https://gist.github.com/marekjelen/2272749

gistfile1.txt

Dead ;)

uninitialized constant Rack::Protection

	org/jruby/RubyModule.java:2642:in `const_missing'
	/Users/marek/.rbenv/versions/jruby-1.6.7/lib/ruby/gems/1.8/gems/rack-protection-1.2.0/lib/rack/protection.rb:23:in `new'
	org/jruby/RubyBasicObject.java:1730:in `instance_eval'
	/Users/marek/.rbenv/versions/jruby-1.6.7/lib/ruby/gems/1.8/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
	/Users/marek/.rbenv/versions/jruby-1.6.7/lib/ruby/gems/1.8/gems/rack-protection-1.2.0/lib/rack/protection.rb:22:in `new'
	/Users/marek/.rbenv/versions/jruby-1.6.7/lib/ruby/gems/1.8/gems/rack-1.4.1/lib/rack/builder.rb:82:in `use'

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https://github.com/marekjelen/thick/blob/loader/lib/thick/loader.rb
https://github.com/rkh/rack-protection/blob/master/lib/rack/protection.rb

Any ideas?

Thanks

–
Marek J.

m: +420 724 255807
e: [email protected]

marek_j · April 1, 2012, 5:15pm

That is odd!

I was surprised that you’ve been able to just call “require ‘rack’”
without requiring rubygems or setting up your GEM_PATH inside the new
runtime. One thing I failed to show from my app was a boot.rb, which
was the first thing I ran in the embedded JRuby. It that did all that:

gist.github.com

https://gist.github.com/jkutner/2268163

boot.rb

$LOAD_PATH << $APP_LOAD_PATH  #set the load path from the APP_LOAD_PATH binding

if $RACK_ENV == 'production'
  ENV['GEM_PATH'] = "#{File.join($RULE_SERVER_HOME, 'vendor/jruby/1.8')}:#{File.join($TORQUEBOX_HOME, 'jruby/lib/ruby/gems/1.8')}"
  ENV['GEM_HOME'] = File.join($RULE_SERVER_HOME, 'vendor/jruby/1.8')
else
  puts 'Using global GEM_HOME directory.'
end

require 'rubygems'

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engine.rb

java_import "javax.script.ScriptContext"
java_import "javax.script.ScriptEngine"
java_import "javax.script.ScriptEngineManager"
java_import "javax.script.ScriptException"
java_import "java.io.FileNotFoundException"
java_import "javax.script.Bindings"
java_import "javax.script.SimpleBindings"
java_import "java.io.FileReader"
java_import "java.io.Reader"

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So i tried to tweak my example to reproduce your error, but I could not
(granted, it doesn’t do quite what you intended yet):

How are you running your app? I’d like to mess around with it and see
if I can get anywhere.

marek_j · April 1, 2012, 5:34pm

I guess I am inheriting some things from outside or some environment is
being shared. It works without anything like boot.rb file for simple
Rack
applications … with Sinatra it does not however.

clone GitHub - marekjelen/thick: [Moved, check WildWeb] Lightweight web server for JRuby, enter, and checkout
“loader”
branch
create config.ru from Simple Sinatra · GitHub
run jruby bin/thick

You need to have rack and sinatra installed.

That’s all.

Thanks for help.

–
Marek J.

m: +420 724 255807
e: [email protected]

marek_j · April 1, 2012, 6:47pm

I think you’d better double check ScriptingContainer knows where all
gems are. The error you got means ScriptingContainer doesn’t know the
definition of “::Rack::Protection::FrameOptions” .

If you don’t pack up all in a jar, setting GEM_PATH on the
ScriptingContainer would work. If you will pack in a jar, you should
set each path to gems using setLoadPath() method. This is cumbersome,
but the best to avoid path related problems.

My blog post,

, or page 26 - 31 of my presentation slide,
http://redbridge-at-strangeloop2011.herokuapp.com/slideshow , may help
you to understand.

Since you (Marek) correctly instantiated a singlethreaded
ScriptingContainer, perhaps next to check is loading paths.

As far as I tried on the irb, ScriptingContainer created another
instance of Ruby runtime:

irb(main):002:0> require ‘java’
=> true
irb(main):003:0> JRuby.runtime
=> #Java::OrgJruby::Ruby:0x394a8cd1 <— irb’s
runtime
irb(main):004:0> c =
org.jruby.embed.ScriptingContainer.new(org.jruby.embed.LocalContextScope::SINGLETHREAD)
=> #Java::OrgJrubyEmbed::ScriptingContainer:0x7664e5b2
irb(main):005:0> c.getProvider.getRuntime
=> #Java::OrgJruby::Ruby:0x5f5fc606 <—
another runtime instance
irb(main):006:0> ABC = 10
=> 10
irb(main):007:0> c.run_scriptlet(“ABC=100”)
=> 100
irb(main):008:0> ABC
=> 10
<— irb says ABC is 10
irb(main):009:0> c.run_scriptlet(“ABC”)
=> 100
<— ScriptingContainer says ABC is 100

Yoko

marek_j · April 1, 2012, 6:53pm

As far as I tried on the irb, ScriptingContainer created another
instance of Ruby runtime:

See Ruby runtimes of singlethreaded ScriptingContainer and irb · GitHub . Below is hard to read.

-Yoko

marek_j · March 31, 2012, 10:15pm

Hello,

thanks for response.

puts container.getProvider.class #
=> Java::OrgJrubyEmbedInternal::SingleThreadLocalContextProvider

I really hope it’s possible to use it this way

–
Marek J.

m: +420 724 255807
e: [email protected]