Unable to run ruby script from php due to gem_original_require error

Question

I am trying to run a ruby script from php (browser) that requires some gems. VPS: CentOS, PHP5, ruby2.0.0, using RVM. I reach the server via PUTTY and I ran the php code from browser.

So when I run this:

<?php
$descriptorspec = array(
   0 => array("pipe", "r"),
   1 => array("pipe", "w"),
   2 => array("file", "./error-output.txt", "a")
);
$process = proc_open('ruby /home/balint/test.rb', $descriptorspec, $pipes);

if (is_resource($process)) {
    fwrite($pipes[0], 'hello world');
    fclose($pipes[0]);

    echo stream_get_contents($pipes[1]);
    fclose($pipes[1]);

    $return_value = proc_close($process);

    echo "command returned $return_value\n";
}
?>

And the test.rb script includes only puts "xxx" then I get the output on my screen as xxx.

However, when I include some gems like require 'nokogiri' I get this in the error log:

/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': no such file to load -- nokogiri (LoadError)
    from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
    from /home/balint/test.rb:5

This is working fine directly from shell.

ruby -v:

ruby 2.0.0p643 (2015-02-25 revision 49749) [x86_64-linux]

which ruby:

/usr/bin/ruby

gem env:

RubyGems Environment:
  - RUBYGEMS VERSION: 2.4.8
  - RUBY VERSION: 2.0.0 (2015-02-25 patchlevel 643) [x86_64-linux]
  - INSTALLATION DIRECTORY: /home/balint/.rvm/gems/ruby-2.0.0-p643
  - RUBY EXECUTABLE: /home/balint/.rvm/rubies/ruby-2.0.0-p643/bin/ruby
  - EXECUTABLE DIRECTORY: /home/balint/.rvm/gems/ruby-2.0.0-p643/bin
  - SPEC CACHE DIRECTORY: /home/balint/.gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /home/balint/.rvm/rubies/ruby-2.0.0-p643/etc
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /home/balint/.rvm/gems/ruby-2.0.0-p643
     - /home/balint/.rvm/gems/ruby-2.0.0-p643@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
     - :sources => ["https://rubygems.org/", "http://rubygems.org"]
  - REMOTE SOURCES:
     - https://rubygems.org/
     - http://rubygems.org
  - SHELL PATH:
     - /usr/local/jdk/bin
     - /home/balint/.rvm/gems/ruby-2.0.0-p643/bin
     - /home/balint/.rvm/gems/ruby-2.0.0-p643@global/bin
     - /home/balint/.rvm/rubies/ruby-2.0.0-p643/bin
     - /home/balint/perl5/bin
     - /usr/local/bin
     - /bin
     - /usr/bin
     - /usr/local/sbin
     - /usr/sbin
     - /sbin
     - /home/balint/.rvm/bin
     - /usr/local/bin
     - /usr/X11R6/bin
     - /home/balint/.rvm/bin
     - /home/balint/bin

echo $PATH

/usr/local/jdk/bin:/home/balint/.rvm/gems/ruby-2.0.0-p643/bin:/home/balint/.rvm/gems/ruby-2.0.0-p643@global/bin:/home/balint/.rvm/rubies/ruby-2.0.0-p643/bin:/home/balint/perl5/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/balint/.rvm/bin:/usr/local/bin:/usr/X11R6/bin:/home/balint/.rvm/bin:/home/balint/bin

According to the log it's looking in the 1.8 folder. But there is no other folder in usr/lib/ruby/site_ruby/ than 1.8. And I also don't understand why it's working in shell and why it's not from the browser.

Can someone put me in the right direction here?

Answer 1

When PHP tries to run a script, it's very likely running with very reduced privileges and a limited env and PATH. Its path is different than yours, which you see in your shell.

Check to see what the PHP session runs as. It is most likely the server's env. Also check to see whether the server knows about RVM, and can see the proper gem env. That would explain why the server sees /usr/lib/ruby/site_ruby/1.8/ and you see the RVM hosted Ruby.

Also, unless the path of the server is able to find the right Ruby, using

ruby /home/balint/test.rb

it is going to launch the first Ruby found in the PATH, which will probably be /usr/bin/ruby. Instead ALWAYS force the path to the Ruby you want. For the built-in Ruby that'd be:

/usr/bin/ruby /home/balint/test.rb

Throwing RVM into the mix complicates things a bit, but RVM provides a shim which will honor the --default Ruby you specified or Ruby with gem sets. Read more about working with automated/shelled-out tasks in the RVM cron documentation.