Running Spring as a background process

[AhmedAttyah]

Problem:

When we tried to start spring as background process on CircleCI we got this error:

/home/ubuntu/fundbase/vendor/bundle/ruby/1.9.1/bundler/gems/spring-5b27cda52354/lib/spring/sid.rb:41:in `getpgid': No such process (Errno::ESRCH)
    from /home/ubuntu/fundbase/vendor/bundle/ruby/1.9.1/bundler/gems/spring-5b27cda52354/lib/spring/sid.rb:41:in `pgid'
    from /home/ubuntu/fundbase/vendor/bundle/ruby/1.9.1/bundler/gems/spring-5b27cda52354/lib/spring/server.rb:78:in `set_pgid'

The reason behind this error according to https://github.com/rails/spring/issues/231#issuecomment-31556537 is that CircleCI runs a background process with a command equivalent to nohup bash -c "./daemon &" and since there is no associated terminal Process.getsid is returning nil or 0.

Solution:

After some debugging i found that we actually don't need process group ID pgid on CircleCI and that Session ID sid is sufficient to keep spring running in background. Thus, i modified self.pgid method to be:

def self.pgid
  return sid if ENV['CIRCLECI']
  Process.getpgid(sid)
end

So, I've 2 questions: 1- I'm not sure what can go wrong if we relied on sid only for background processes?. 2- can we make this configurable ?.

[willian]

:+1:

[schasse]

+1

[oklas]

Hi! I have same problem on FreeBSD 9.3 (csh) (Rails 4.2.6 Ruby 2.1.7p400)

when I try to

bundle exec spring

It crash and result is:

/home/zYL1WK4y/.bundle/gems/spring-1.6.3/lib/spring/sid.rb:40:in `getpgid': No such process (Errno::ESRCH)
    from /home/zYL1WK4y/.bundle/gems/spring-1.6.3/lib/spring/sid.rb:40:in `pgid'
    from /home/zYL1WK4y/.bundle/gems/spring-1.6.3/lib/spring/server.rb:78:in `set_pgid'
    from /home/zYL1WK4y/.bundle/gems/spring-1.6.3/lib/spring/server.rb:34:in `boot'
    from /home/zYL1WK4y/.bundle/gems/spring-1.6.3/lib/spring/server.rb:14:in `boot'
    from -e:1:in `<main>'

Problem temporary worked around with code like above showed @AhmedAttyah - thanks for save time! But with no configuration option, becouse have FreeBSD and have no CircleCi:

def self.pgid
  return sid
  Process.getpgid(sid)
end

Distinctly there is no compatibility in this place.

I have try to debug like this:

def set_pgid
  require 'pp';
  begin
    pp SID
    pp SID.pgid
    pp Process.setpgid(0, SID.pgid)
  rescue Exception => e
    puts "exception: #{e.message}"
  end
  Process.setpgid(0, SID.pgid)
end

The result is:

Spring::SID
exception: No such process

It is wanted to have notification with recomendations instead of crash and make it configurable somehow (or any another way to work)

[oklas]

Does anyone still have such a problem with the new version (check author comment at #504). It would be nice to confirm and to close this one of the issues.