unicorn Ruby/Rack server user+dev discussion/patches/pulls/bugs/help
 help / color / mirror / code / Atom feed
From: Tatsuya Ono <ononoma@gmail.com>
To: mongrel-unicorn <mongrel-unicorn@rubyforge.org>
Subject: Unicorn in the jail
Date: Wed, 3 Aug 2011 17:41:03 +0100	[thread overview]
Message-ID: <CAHBuKRj09FdxAgzsefJWotexw-7JYZGJMtgUp_dhjPz9VbKD6Q@mail.gmail.com> (raw)

I ran into a problem when sending USR2 signal to master process which
is listening a TCP port. It shows the following error in log.

err: adding listener failed addr=0.0.0.0:3010 (in use)

I found similar error reported on this mailing list and yes, the host
I got the error was in the FreeBSD jail.
http://rubyforge.org/pipermail/mongrel-unicorn/2009-December/000205.html
http://rubyforge.org/pipermail/mongrel-unicorn/2009-December/000212.html

I dug into the problem and found some interesting thing. I want to
share it and the solution here.

* Why does it happen in the Jail?
When you bind 0.0.0.0 address to the socket on a Jail host, Jail
doesn't bind 0.0.0.0. Instead of it, it binds to the IP address of the
host such as 10.100.1.50, 192.168.1.50, etc.
Then the problem happens in Unicorn::HttpServer#inherit_listeners!
when it gets signal like USR2.
https://github.com/defunkt/unicorn/blob/406b8b0e2ed6e5be34d8ec3cd4b16048233c2856/lib/unicorn/http_server.rb#L703-731

Here you get 10.100.1.50 (for example) as inherited address from
ENV['UNICORN_FD'] but 0.0.0.0. So Unicorn tries to bind to 0.0.0.0
(again) at line 728. Then it fails because it is actually in use.

* How to solve the issue?
Thankfully unicorn.conf is ruby script so that I could write a logic
for Jail hosts without specifying IP address of those hosts (which we
want to avoid since we deploy it multiple servers). I share the
configuration file.
https://gist.github.com/1122965

Then Unicorn flies in the jail happily.

Tatsuya Ono
_______________________________________________
Unicorn mailing list - mongrel-unicorn@rubyforge.org
http://rubyforge.org/mailman/listinfo/mongrel-unicorn
Do not quote signatures (like this one) or top post when replying


             reply	other threads:[~2011-08-03 16:48 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-03 16:41 Tatsuya Ono [this message]
2011-08-03 18:03 ` Unicorn in the jail Eric Wong
2011-08-03 21:57   ` Tatsuya Ono

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://yhbt.net/unicorn/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAHBuKRj09FdxAgzsefJWotexw-7JYZGJMtgUp_dhjPz9VbKD6Q@mail.gmail.com \
    --to=ononoma@gmail.com \
    --cc=mongrel-unicorn@rubyforge.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
Code repositories for project(s) associated with this public inbox

	https://yhbt.net/unicorn.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).