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Connect to Pry remotely using EventMachine with tab-completion, paging, user authentication and SSL support

README.md

PryRemoteEm enables you to start instances of Pry in a running EventMachine program and connect to those Pry instances over a network or the Internet. Once connected you can interact with the internal state of the program.

It's based off of Mon-Ouie's pry-remote for DRb.

It adds user authentication and SSL support along with tab-completion and paging. It's compatble with MRI 1.9, or any other VM with support for Fibers and EventMachine.

Installation

gem install pry-remote-em

Usage

require 'pry-remote-em/server'

class Foo
  def initialize(x, y)
    binding.remote_pry_em
  end
end

EM.run { Foo.new 10, 20 } 

Running it will print out a message telling you Pry is waiting for a program to connect itself to it:

 [pry-remote-em] listening for connections on pryem://localhost:6462/

You can then connect to the pry session using pry-remote-em:

$ pry-remote-em pryem://127.0.0.1:6462/
[pry-remote-em] client connected to pryem://127.0.0.1:6462/
[pry-remote-em] remote is PryRemoteEm 0.1.0
[1] pry(#<Foo>)> stat
Method Information:
--
Name: initialize
Owner: Foo
Visibility: private
Type: Bound
Arity: 2
Method Signature: initialize(x, y)
Source Location: (irb):2

[2] pry(#<Foo>)> self
=> #<Foo:0x007fe66a426fa0>

[3] pry(#<Foo>)> ls
locals: _  _dir_  _ex_  _file_  _in_  _out_  _pry_  x  y
[4] pry(#<Foo>)> x
=> 10

[5] pry(#<Foo>)> x = 12
=> 12

[6] pry(#<Foo>)> x
=> 12

[7] pry(#<Foo>)> exit
[pry-remote-em] session terminated

$ pry-remote-em pryem://127.0.0.1:6462/
[pry-remote-em] client connected to pryem://127.0.0.1:6462/
[pry-remote-em] remote is PryRemoteEm 0.1.0
[1] pry(#<Foo>)> x
=> 12

[2] pry(#<Foo>)> exit
[pry-remote-em] session terminated

Features

Multiple Servers

It's easy to run more than one PryRemoteEm service on a single machine, or even in the same process. When you start the service via #remote_pry_em, just specify :auto as the port to use. The service will automatically take the next free port from 6462.

require "pry-remote-em/server"

os     = ObjectSpace.each_object
expose = []
while expose.length < 5
  o = os.next
  expose.push(o) unless o.frozen?
end

EM.run {
  expose.each {|o| o.remote_pry_em('localhost', :auto) }
}
$ ruby test/auto-demo.rb
[pry-remote-em] listening for connections on pryem://localhost:6462/
[pry-remote-em] listening for connections on pryem://localhost:6463/
[pry-remote-em] listening for connections on pryem://localhost:6464/
[pry-remote-em] listening for connections on pryem://localhost:6465/
[pry-remote-em] listening for connections on pryem://localhost:6466/

$ pry-remote-em pryem://127.0.0.1:6462/
[pry-remote-em] client connected to pryem://127.0.0.1:6462/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryem
[1] pry("pretty_print")> 

$ pry-remote-em  pryem://127.0.0.1:6463/
[pry-remote-em] client connected to pryem://127.0.0.1:6463/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryem
[1] pry("pack")> 

$ pry-remote-em  pryem://127.0.0.1:6464/
[pry-remote-em] client connected to pryem://127.0.0.1:6464/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryem
[1] pry("to_json")>

$ pry-remote-em  pryem://127.0.0.1:6465/
[pry-remote-em] client connected to pryem://127.0.0.1:6465/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryem
[1] pry("to_json")> 

$ pry-remote-em  pryem://127.0.0.1:6466/
[pry-remote-em] client connected to pryem://127.0.0.1:6466/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryem
[1] pry(#<RubyVM::InstructionSequence>)> 

Server Broker

When more than one server is running on a given host and each server is started with :auto it can be time consuming to manually figure out which port each server is running on. The Broker which listens on port 6461 keeps track of which server is running on which port.

By default the pry-remote-em cli utility will connect to the broker and retrieve a list of known servers. You can then select one to connect to by its id, name or url. You can also choose to proxy your connection through the broker to the selected server.


$ bin/pry-remote-em
[pry-remote-em] client connected to pryem://127.0.0.1:6461/
[pry-remote-em] remote is PryRemoteEm 0.7.0 pryem
-----------------------------------------------------------------------------
| id  |  name                              |  url                           |
-----------------------------------------------------------------------------
|  1  |  #<#<Class:0x007f924b9bbee8>>      |  pryem://127.0.0.1:6462/       |
|  2  |  #<Foo>                            |  pryem://127.0.0.1:1337/       |
|  3  |  #<#<Class:0x007f924b9bbee8>>      |  pryems://127.0.0.1:6463/      |
|  4  |  #<#<Class:0x007f924b9bbee8>>      |  pryems://127.0.0.1:6464/      |
|  5  |  #<#<Class:0x007f924b9bbee8>>      |  pryems://127.0.0.1:6465/      |
|  6  |  #<#<Class:0x007f924b9bbee8>>      |  pryems://127.0.0.1:6466/      |
|  7  |  #<#<Class:0x007f924b9bbee8>>      |  pryems://127.0.0.1:6467/      |
|  8  |  #<#<Class:0x007f924b9bbee8>>      |  pryem://127.0.0.1:6468/       |
|  9  |  #<#<Class:0x007f924b9bbee8>>      |  pryem://127.0.0.1:6469/       |
-----------------------------------------------------------------------------
(q) to quit; (r) to refresh (p) to proxy
connect to: 3
[pry-remote-em] client connected to pryem://127.0.0.1:6463/
[pry-remote-em] remote is PryRemoteEm 0.7.0 pryems
[pry-remote-em] negotiating TLS
[pry-remote-em] TLS connection established
[1] pry(#<#<Class:0x007f924b9bbee8>>)>

By default the Broker will listen on 127.0.0.1:6461. To change the ip address that the Broker binds to specify it in a PRYEMBROKER environment variable, or in :broker_host option passed to #remote_pry_em.


$ PRYEMBROKER=0.0.0.0 be ./test/service.rb  
I, [2012-07-13T21:10:00.936993 #88528]  INFO -- : [pry-remote-em] listening for connections on pryem://0.0.0.0:6462/
I, [2012-07-13T21:10:00.937132 #88528]  INFO -- : [pry-remote-em broker] listening on pryem://0.0.0.0:6461
I, [2012-07-13T21:10:00.937264 #88528]  INFO -- : [pry-remote-em] listening for connections on pryem://0.0.0.0:1337/
I, [2012-07-13T21:10:00.937533 #88528]  INFO -- : [pry-remote-em] listening for connections on pryems://0.0.0.0:6463/
I, [2012-07-13T21:10:00.937804 #88528]  INFO -- : [pry-remote-em] listening for connections on pryems://0.0.0.0:6464/
I, [2012-07-13T21:10:00.938126 #88528]  INFO -- : [pry-remote-em] listening for connections on pryems://0.0.0.0:6465/
I, [2012-07-13T21:10:00.938471 #88528]  INFO -- : [pry-remote-em] listening for connections on pryems://0.0.0.0:6466/
I, [2012-07-13T21:10:00.938835 #88528]  INFO -- : [pry-remote-em] listening for connections on pryems://0.0.0.0:6467/
I, [2012-07-13T21:10:00.939230 #88528]  INFO -- : [pry-remote-em] listening for connections on pryem://0.0.0.0:6468/
I, [2012-07-13T21:10:00.939640 #88528]  INFO -- : [pry-remote-em] listening for connections on pryem://0.0.0.0:6469/
I, [2012-07-13T21:10:01.031576 #88528]  INFO -- : [pry-remote-em broker] received client connection from 127.0.0.1:62288
I, [2012-07-13T21:10:01.031931 #88528]  INFO -- : [pry-remote-em] client connected to pryem://127.0.0.1:6461/
I, [2012-07-13T21:10:01.032120 #88528]  INFO -- : [pry-remote-em] remote is PryRemoteEm 0.7.0 pryem
I, [2012-07-13T21:10:01.032890 #88528]  INFO -- : [pry-remote-em broker] registered pryem://127.0.0.1:6462/ - "#<#<Class:0x007f924b9bbee8>>" 
I, [2012-07-13T21:10:01.125123 #88528]  INFO -- : [pry-remote-em broker] registered pryem://127.0.0.1:6469/ - "#<#<Class:0x007f924b9bbee8>>" 
I, [2012-07-13T21:10:01.125487 #88528]  INFO -- : [pry-remote-em broker] registered pryems://127.0.0.1:6467/ - "#<#<Class:0x007f924b9bbee8>>"
I, [2012-07-13T21:10:01.490729 #88528]  INFO -- : [pry-remote-em broker] registered pryems://127.0.0.1:6464/ - "#<#<Class:0x007f924b9bbee8>>"
I, [2012-07-13T21:10:01.583015 #88528]  INFO -- : [pry-remote-em broker] registered pryem://127.0.0.1:1337/ - "#<Foo>"                       
I, [2012-07-13T21:10:01.674842 #88528]  INFO -- : [pry-remote-em broker] registered pryems://127.0.0.1:6466/ - "#<#<Class:0x007f924b9bbee8>>"
I, [2012-07-13T21:10:01.766813 #88528]  INFO -- : [pry-remote-em broker] registered pryem://127.0.0.1:6468/ - "#<#<Class:0x007f924b9bbee8>>" 
I, [2012-07-13T21:10:01.858423 #88528]  INFO -- : [pry-remote-em broker] registered pryems://127.0.0.1:6465/ - "#<#<Class:0x007f924b9bbee8>>"

It is possible to have a pry-remote-em server register with a Broker running on a different host. Just specify the Brokers address in the PRYEMBROKER environment variable or the :broker_host option passed to #remote_pry_em.

To connect to a broker running on a seperate host with the cli client just specify it on the command line bin/pry-remote-em preym://10.0.0.2:6461/. You can then proxy your client connections to remote servers through that Broker.

The Broker will not run in TLS mode, but it can proxy connections to a TLS enabled server.

TLS Encryption

When creating a server pass the :tls => true option to enable TLS.

obj.remote_pry_em('localhost', :auto, :tls => true)

If you pass a Hash it will be used to configure the internal TLS handler.

obj.remote_pry_em('localhost', :auto, :tls => {:private_key_file => '/tmp/server.key'})

See EventMachine::Connection#start_tls for the available options.

When the command line client connects to a TLS enabled server it will automatically use TLS mode even if the user didn't request it.

$ pry-remote-em pryem://localhost:6462/
[pry-remote-em] client connected to pryem://127.0.0.1:6462/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryems
[pry-remote-em] negotiating TLS
[pry-remote-em] TLS connection established
[1] pry(#<Hash>)> 

To always require a TLS connection give pry-remote-em a pryem*s* URL. If the server doesn't support TLS the connection will be terminated.

$ pry-remote-em pryems://localhost:6468/
[pry-remote-em] client connected to pryem://127.0.0.1:6468/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryem
[pry-remote-em] connection failed
[pry-remote-em] server doesn't support required scheme "pryems"
[pry-remote-em] session terminated

User Authentication

Server

If the service is started with the :auth option it will require all clients to authenticate on connect. The :auth option can be a Hash, proc or any object that responds to #call.

Auth with a Hash

auth_hash = {'caleb' => 'crane', 'john' => 'lowski'}
obj       = {:encoding => __ENCODING__, :weather => :cloudy}
EM.run{
  obj.remote_pry_em('localhost', :auto, :tls => true, :auth => auth_hash)
}

Auth with a lambda

require 'net/ldap'
ldap_anon = lambda do |user, pass|
  ldap = Net::LDAP.new :host => '10.0.0.1', :port => 389, :auth => {:method => :simple, :username => user, :password => pass}
  ldap.bind
end
obj       = {:encoding => __ENCODING__, :weather => :cloudy}
EM.run{
  obj.remote_pry_em('localhost', :auto, :tls => true, :auth => ldap_anon)
}

Auth with an object

class Authenticator
  def initialize(db)
    @db = db
  end
  def call(user, pass)
    @db[user] && @db[user] == pass
  end
end

obj       = {:encoding => __ENCODING__, :weather => :cloudy}
EM.run{
  obj.remote_pry_em('localhost', :auto, :tls => true, :auth => Authenticator.new(auth_hash))
}

Client

The included command line client pry-remote-em can take a username and/or password as part of the url argument. If either a username or password is not supplied, but required by the server it will prompt for them.

$ pry-remote-em pryems://localhost:6464/
[pry-remote-em] client connected to pryem://127.0.0.1:6464/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryems
[pry-remote-em] negotiating TLS
[pry-remote-em] TLS connection established
user: caleb
caleb's password: *****
[1] pry(#<Hash>)> 
$ pry-remote-em pryems://caleb@localhost:6464
[pry-remote-em] client connected to pryem://127.0.0.1:6464/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryems
[pry-remote-em] negotiating TLS
[pry-remote-em] TLS connection established
caleb's password: *****
[1] pry(#<Hash>)> exit
$ pry-remote-em pryems://caleb:crane@localhost:6464
[pry-remote-em] client connected to pryem://127.0.0.1:6464/
[pry-remote-em] remote is PryRemoteEm 0.4.0 pryems
[pry-remote-em] negotiating TLS
[pry-remote-em] TLS connection established
[1] pry(#<Hash>)> exit

Tab Completion

Tab completion candidates will be retrieved from the server and presented on the client side.

$ bin/pry-remote-em pryems:///
[pry-remote-em] client connected to pryem://127.0.0.1:6462/
[pry-remote-em] remote is PryRemoteEm 0.2.0 pryems
[1] pry(#<Hash>)> key (^TAB ^TAB)
key   key?  keys  
[1] pry(#<Hash>)> keys
=> [:encoding]

Paging

The standard Pry pager is supported through the included client.

[1] pry(#<Hash>)> ENV
=> {"COMMAND_MODE"=>"unix2003",
 "DISPLAY"=>"/tmp/launch-0EGhJW/org.x:0",
 "EDITOR"=>"mvim -f --nomru -c \"au VimLeave * !open -a Terminal\"",
 "GEM_HOME"=>"/Users/caleb/.rvm/gems/ruby-1.9.2-p290",
 "GEM_PATH"=>
  "/Users/caleb/.rvm/gems/ruby-1.9.2-p290:/Users/caleb/.rvm/gems/ruby-1.9.2-p290@global",
 "GREP_COLOR"=>"1;32",
 "GREP_OPTIONS"=>"--color=auto",
 "HOME"=>"/Users/caleb",
 "IRBRC"=>"/Users/caleb/.rvm/rubies/ruby-1.9.2-p290/.irbrc",
 "LC_CTYPE"=>"",
 "LOGNAME"=>"caleb",
 "LSCOLORS"=>"Gxfxcxdxbxegedabagacad",
:

Messaging

It is possible for each pry-remote-em service to host multiple simultaneous connections. You can send messages to other connections with the '!' and '!!' prefix.

The '!' prefix will send the message to connections on the same object. the '!!' prefix will send the message to all connections in the current process.

Message will not be displayed by the clients until the presses enter.

Authentication Event Callbacks

Available events are:

  • auth_attempt - called each time authentication is attempted
  • auth_fail - called each time authentication fails
  • auth_ok - called each time authentication succeeds
log         = ::Logger.new('/var/log/auth.pry.log')
obj.new.remote_pry_em('0.0.0.0', :auto, :tls => true, :auth => auth_hash) do |pry|
  pry.auth_attempt do |user, ip|
    log.info("got an authentication attempt for #{user} from #{ip}")
  end
  pry.auth_fail do |user, ip|
    log.fatal("failed authentication attempt for #{user} from #{ip}")
  end
  pry.auth_ok do |user, ip|
    log.info("successful authentication for #{user} from #{ip}")
  end
end

Shell Commands

If the pry-remote-em service is started with the :allow_shell_cmds => true option set it will spawn sub processes for any command prefixed with a '.'.

[1] pry(#<#<Class:0x007fe0be072618>>)> .uname -a
Darwin kiff.local 11.3.0 Darwin Kernel Version 11.3.0: Thu Jan 12 18:47:41 PST 2012; root:xnu-1699.24.23~1/RELEASE_X86_64 x86_64

Interactive commands like vim will probably not behave appropriately.

If the server was not started with the allow_shell_cmds option then all shell commands will be met with a rejection notice.

[1] pry(#<#<Class:0x007fe0be072618>>)> .ls
shell commands are not allowed by this server

The server will also log whenever a user attempts to execute a shell command.

W, [2012-02-11T19:21:27.663941 #36471]  WARN -- : executing shell command 'ls -al' for  (127.0.0.1:63878)
E, [2012-02-11T19:23:40.770380 #36471] ERROR -- : refused to execute shell command 'ls' for caleb (127.0.0.1:63891)

Missing Features

  • HTTP Transport ticket
  • Ssh key based authentication

Issues

Please post any bug reports or feature requests on Github

Copyright

Copyright (c) 2012 Caleb Crane

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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