.TH UNICORN_RAILS 1 "September 17, 2009" "Unicorn User Manual"
.SH NAME
.PP
unicorn_rails - a script/server-like command to launch the Unicorn
HTTP server
.SH SYNOPSIS
.PP
unicorn_rails [\-c CONFIG_FILE] [\-E RAILS_ENV] [\-D] [RACKUP_FILE]
.SH DESCRIPTION
.PP
A rackup(1)-like command to launch Rails applications using
Unicorn.
It is expected to be started in your Rails application root
(RAILS_ROOT), but the \[lq]working_directory\[rq] directive may be
used in the CONFIG_FILE.
.PP
It is designed to help Rails 1.x and 2.y users transition to Rack,
but it is NOT needed for Rails 3 applications.
Rails 3 users are encouraged to use unicorn(1) instead of
unicorn_rails(1).
Users of Rails 1.x/2.y may also use unicorn(1) instead of
unicorn_rails(1).
.PP
The outward interface resembles rackup(1), the internals and
default middleware loading is designed like the
\f[B]script/server\f[] command distributed with Rails.
.PP
While Unicorn takes a myriad of command-line options for
compatibility with ruby(1) and rackup(1), it is recommended to
stick to the few command-line options specified in the SYNOPSIS and
use the CONFIG_FILE as much as possible.
.SH UNICORN OPTIONS
.TP
.B \-c, \-\-config-file CONFIG_FILE
Path to the Unicorn-specific config file.
The config file is implemented as a Ruby DSL, so Ruby code may
executed.
See the RDoc/ri for the \f[I]Unicorn::Configurator\f[] class for
the full list of directives available from the DSL.
Using an absolute path for for CONFIG_FILE is recommended as it
makes multiple instances of Unicorn easily distinguishable when
viewing ps(1) output.
.RS
.RE
.TP
.B \-D, \-\-daemonize
Run daemonized in the background.
The process is detached from the controlling terminal and stdin is
redirected to \[lq]/dev/null\[rq].
Unlike many common UNIX daemons, we do not chdir to "/" upon
daemonization to allow more control over the startup/upgrade
process.
Unless specified in the CONFIG_FILE, stderr and stdout will also be
redirected to \[lq]/dev/null\[rq].
Daemonization will \f[I]skip\f[] loading of the
\f[I]Rails::Rack::LogTailer\f[] middleware under Rails >= 2.3.x.
By default, unicorn_rails(1) will create a PID file in
\f[I]"RAILS_ROOT/tmp/pids/unicorn.pid"\f[].
You may override this by specifying the \[lq]pid\[rq] directive to
override this Unicorn config file.
.RS
.RE
.TP
.B \-E, \-\-env RAILS_ENV
Run under the given RAILS_ENV.
This sets the RAILS_ENV environment variable.
Acceptable values are exactly those you expect in your Rails
application, typically \[lq]development\[rq] or
\[lq]production\[rq].
.RS
.RE
.TP
.B \-l, \-\-listen ADDRESS
Listens on a given ADDRESS.
ADDRESS may be in the form of HOST:PORT or PATH, HOST:PORT is taken
to mean a TCP socket and PATH is meant to be a path to a UNIX
domain socket.
Defaults to \[lq]0.0.0.0:8080\[rq] (all addresses on TCP port
8080).
For production deployments, specifying the \[lq]listen\[rq]
directive in CONFIG_FILE is recommended as it allows fine-tuning of
socket options.
.RS
.RE
.SH RACKUP COMPATIBILITY OPTIONS
.TP
.B \-o, \-\-host HOST
Listen on a TCP socket belonging to HOST, default is
\[lq]0.0.0.0\[rq] (all addresses).
If specified multiple times on the command-line, only the
last-specified value takes effect.
This option only exists for compatibility with the rackup(1)
command, use of \[lq]\-l\[rq]/\[lq]\-\-listen\[rq] switch is
recommended instead.
.RS
.RE
.TP
.B \-p, \-\-port PORT
Listen on the specified TCP PORT, default is 8080.
If specified multiple times on the command-line, only the
last-specified value takes effect.
This option only exists for compatibility with the rackup(1)
command, use of \[lq]\-l\[rq]/\[lq]\-\-listen\[rq] switch is
recommended instead.
.RS
.RE
.TP
.B \-\-path PATH
Mounts the Rails application at the given PATH (instead of
\[lq]/\[rq]).
This is equivalent to setting the RAILS_RELATIVE_URL_ROOT
environment variable.
This is only supported under Rails 2.3 or later at the moment.
.RS
.RE
.SH RUBY OPTIONS
.TP
.B \-e, \-\-eval LINE
Evaluate a LINE of Ruby code.
This evaluation happens immediately as the command-line is being
parsed.
.RS
.RE
.TP
.B \-d, \-\-debug
Turn on debug mode, the $DEBUG variable is set to true.
For Rails >= 2.3.x, this loads the \f[I]Rails::Rack::Debugger\f[]
middleware.
.RS
.RE
.TP
.B \-w, \-\-warn
Turn on verbose warnings, the $VERBOSE variable is set to true.
.RS
.RE
.TP
.B \-I, \-\-include PATH
specify $LOAD_PATH.
PATH will be prepended to $LOAD_PATH.
The \[aq]:\[aq] character may be used to delimit multiple
directories.
This directive may be used more than once.
Modifications to $LOAD_PATH take place immediately and in the order
they were specified on the command-line.
.RS
.RE
.TP
.B \-r, \-\-require LIBRARY
require a specified LIBRARY before executing the application.
The "require" statement will be executed immediately and in the
order they were specified on the command-line.
.RS
.RE
.SH RACKUP FILE
.PP
This defaults to "config.ru" in RAILS_ROOT.
It should be the same file used by rackup(1) and other Rack
launchers, it uses the \f[I]Rack::Builder\f[] DSL.
Unlike many other Rack applications, RACKUP_FILE is completely
\f[I]optional\f[] for Rails, but may be used to disable some of the
default middleware for performance.
.PP
Embedded command-line options are mostly parsed for compatibility
with rackup(1) but strongly discouraged.
.SH ENVIRONMENT VARIABLES
.PP
The RAILS_ENV variable is set by the aforementioned \-E switch.
The RAILS_RELATIVE_URL_ROOT is set by the aforementioned \-\-path
switch.
Either of these variables may also be set in the shell or the
Unicorn CONFIG_FILE.
All application or library-specific environment variables (e.g.
TMPDIR, RAILS_ASSET_ID) may always be set in the Unicorn
CONFIG_FILE in addition to the spawning shell.
When transparently upgrading Unicorn, all environment variables set
in the old master process are inherited by the new master process.
Unicorn only uses (and will overwrite) the UNICORN_FD environment
variable internally when doing transparent upgrades.
.SH SIGNALS
.PP
The following UNIX signals may be sent to the master process:
.IP \[bu] 2
HUP - reload config file, app, and gracefully restart all workers
.IP \[bu] 2
INT/TERM - quick shutdown, kills all workers immediately
.IP \[bu] 2
QUIT - graceful shutdown, waits for workers to finish their current
request before finishing.
.IP \[bu] 2
USR1 - reopen all logs owned by the master and all workers See
Unicorn::Util.reopen_logs for what is considered a log.
.IP \[bu] 2
USR2 - reexecute the running binary.
A separate QUIT should be sent to the original process once the
child is verified to be up and running.
.IP \[bu] 2
WINCH - gracefully stops workers but keep the master running.
This will only work for daemonized processes.
.IP \[bu] 2
TTIN - increment the number of worker processes by one
.IP \[bu] 2
TTOU - decrement the number of worker processes by one
.PP
See the SIGNALS (http://unicorn.bogomips.org/SIGNALS.html) document
for full description of all signals used by Unicorn.
.SH SEE ALSO
.IP \[bu] 2
unicorn(1)
.IP \[bu] 2
\f[I]Rack::Builder\f[] ri/RDoc
.IP \[bu] 2
\f[I]Unicorn::Configurator\f[] ri/RDoc
.IP \[bu] 2
Unicorn RDoc (http://unicorn.bogomips.org/)
.IP \[bu] 2
Rack RDoc (http://rack.rubyforge.org/doc/)
.IP \[bu] 2
Rackup HowTo (http://wiki.github.com/rack/rack/tutorial-rackup-howto)
.SH AUTHORS
The Unicorn Community <mongrel-unicorn@rubyforge.org>.