redmine-unicorn-nginx

# this can be any application server, not just Unicorn/Rainbows!
upstream redmine_unicorn {
  # fail_timeout=0 means we always retry an upstream even if it failed
  # to return a good HTTP response (in case the Unicorn master nukes a
  # single worker for timing out).

  # for UNIX domain socket setups:
  server unix:/home/service/shared/socket/redmine/unicorn.sock fail_timeout=0;

  # for TCP setups, point these to your backend servers
  # server 192.168.0.7:8080 fail_timeout=0;
  # server 192.168.0.8:8080 fail_timeout=0;
  # server 192.168.0.9:8080 fail_timeout=0;
}

server {
  # enable one of the following if you're on Linux or FreeBSD
  # listen 80 default deferred; # for Linux
  # listen 80 default accept_filter=httpready; # for FreeBSD

  # If you have IPv6, you'll likely want to have two separate listeners.
  # One on IPv4 only (the default), and another on IPv6 only instead
  # of a single dual-stack listener.  A dual-stack listener will make
  # for ugly IPv4 addresses in $remote_addr (e.g ":ffff:10.0.0.1"
  # instead of just "10.0.0.1") and potentially trigger bugs in
  # some software.
  # listen [::]:80 ipv6only=on; # deferred or accept_filter recommended

  client_max_body_size 4G;
  server_name redmine.yourdomain.com;

  # ~2 seconds is often enough for most folks to parse HTML/CSS and
  # retrieve needed images/icons/frames, connections are cheap in
  # nginx so increasing this is generally safe...
  keepalive_timeout 5;

  # path for static files
  root /home/service/apps/redmine/public;

  # Prefer to serve static files directly from nginx to avoid unnecessary
  # data copies from the application server.
  #
  # try_files directive appeared in in nginx 0.7.27 and has stabilized
  # over time.  Older versions of nginx (e.g. 0.6.x) requires
  # "if (!-f $request_filename)" which was less efficient:
  # http://bogomips.org/unicorn.git/tree/examples/nginx.conf?id=v3.3.1#n127
  try_files $uri/index.html $uri.html $uri @app;

  location @app {
    # an HTTP header important enough to have its own Wikipedia entry:
    #   http://en.wikipedia.org/wiki/X-Forwarded-For
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    # enable this if you forward HTTPS traffic to unicorn,
    # this helps Rack set the proper URL scheme for doing redirects:
    # proxy_set_header X-Forwarded-Proto $scheme;

    # pass the Host: header from the client right along so redirects
    # can be set properly within the Rack application
    proxy_set_header Host $http_host;

    # we don't want nginx trying to do something clever with
    # redirects, we set the Host: header above already.
    proxy_redirect off;

    # set "proxy_buffering off" *only* for Rainbows! when doing
    # Comet/long-poll/streaming.  It's also safe to set if you're using
    # only serving fast clients with Unicorn + nginx, but not slow
    # clients.  You normally want nginx to buffer responses to slow
    # clients, even with Rails 3.1 streaming because otherwise a slow
    # client can become a bottleneck of Unicorn.
    #
    # The Rack application may also set "X-Accel-Buffering (yes|no)"
    # in the response headers do disable/enable buffering on a
    # per-response basis.
    # proxy_buffering off;

    proxy_pass http://redmine_unicorn;
  }

  # Rails error pages
  error_page 500 502 503 504 /500.html;
  location = /500.html {
    root /home/service/apps/redmine/public;
  }
}

Blog post: http://blog.davidanguita.name/2013/03/03/setting-up-a-cheap-redmine-server-using-unicorn-and-apache/