.TH UNICORN 1 "September 15, 2009" "Unicorn User Manual"
.SH NAME
.PP
unicorn - a rackup-like command to launch the Unicorn HTTP server
.SH SYNOPSIS
.PP
unicorn [\-c CONFIG_FILE] [\-E RACK_ENV] [\-D] [RACKUP_FILE]
.SH DESCRIPTION
.PP
A rackup(1)-like command to launch Rack applications using Unicorn.
It is expected to be started in your application root (APP_ROOT),
but the \[lq]working_directory\[rq] directive may be used in the
CONFIG_FILE.
.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 RACKUP FILE
.PP
This defaults to "config.ru" in APP_ROOT.
It should be the same file used by rackup(1) and other Rack
launchers, it uses the \f[I]Rack::Builder\f[] DSL.
.PP
Embedded command-line options are mostly parsed for compatibility
with rackup(1) but strongly discouraged.
.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].
.RS
.RE
.TP
.B \-E, \-\-env RACK_ENV
Run under the given RACK_ENV.
See the RACK ENVIRONMENT section for more details.
.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 \-s, \-\-server SERVER
No-op, this exists only for compatibility with rackup(1).
.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.
.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 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 RACK ENVIRONMENT
.PP
Accepted values of RACK_ENV and the middleware they automatically
load (outside of RACKUP_FILE) are exactly as those in rackup(1):
.IP \[bu] 2
development - loads Rack::CommonLogger, Rack::ShowExceptions, and
Rack::Lint middleware
.IP \[bu] 2
deployment - loads Rack::CommonLogger middleware
.IP \[bu] 2
none - loads no middleware at all, relying entirely on RACKUP_FILE
.PP
All unrecognized values for RACK_ENV are assumed to be
\[lq]none\[rq].
Production deployments are strongly encouraged to use
\[lq]deployment\[rq] or \[lq]none\[rq] for maximum performance.
.PP
As of Unicorn 0.94.0, RACK_ENV is exported as a process-wide
environment variable as well.
While not current a part of the Rack specification as of Rack
1.0.1, this has become a de facto standard in the Rack world.
.PP
Note that the Rack::ContentLength and Rack::Chunked middlewares are
never loaded by default.
If needed, they should be individually specified in the
RACKUP_FILE, some frameworks do not require them.
.SH ENVIRONMENT VARIABLES
.PP
The RACK_ENV variable is set by the aforementioned \-E switch.
All application or library-specific environment variables (e.g.
TMPDIR) 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 SEE ALSO
.IP \[bu] 2
unicorn_rails(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>.