Ubuntu Manpage: unicorn - a rackup-like command to launch the Unicorn HTTP server

NAME

       unicorn - a rackup-like command to launch the Unicorn HTTP server

SYNOPSIS

       unicorn [-c CONFIG_FILE] [-E RACK_ENV] [-D] [RACKUP_FILE]

DESCRIPTION

       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 “working_directory” directive may be used in the CONFIG_FILE.

       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.

RACKUP FILE

       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 Rack::Builder DSL.

       Embedded   command-line  options  are  mostly  parsed  for  compatibility  with  rackup(1)  but  strongly
       discouraged.

UNICORN OPTIONS

-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 Unicorn::Configurator 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.

-D, --daemonize
Run daemonized in the background. The process is detached from the controlling terminal and stdin
is redirected to “/dev/null”. 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 “/dev/null”.

-E, --env RACK_ENV
Run under the given RACK_ENV. See the RACK ENVIRONMENT section for more details.

-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
“0.0.0.0:8080” (all addresses on TCP port 8080) For production deployments, specifying the
“listen” directive in CONFIG_FILE is recommended as it allows fine-tuning of socket options.

-N, --no-default-middleware
Disables loading middleware implied by RACK_ENV. This bypasses the configuration documented in
the RACK ENVIRONMENT section, but still allows RACK_ENV to be used for application/framework-
specific purposes.

RACKUP COMPATIBILITY OPTIONS

       -o, --host HOST
              Listen  on  a  TCP  socket  belonging to HOST, default is “0.0.0.0” (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 “-l”/“--listen” switch is recommended
              instead.

       -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 “-l”/“--listen” switch is recommended instead.

       -s, --server SERVER
              No-op, this exists only for compatibility with rackup(1).

RUBY OPTIONS

       -e, --eval LINE
              Evaluate a LINE of Ruby code.  This evaluation happens immediately as the  command-line  is  being
              parsed.

       -d, --debug
              Turn on debug mode, the $DEBUG variable is set to true.

       -w, --warn
              Turn on verbose warnings, the $VERBOSE variable is set to true.

       -I, --include PATH
              specify  $LOAD_PATH.   PATH  will  be  prepended  to $LOAD_PATH.  The ':' 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.

       -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.

SIGNALS

       The following UNIX signals may be sent to the master process:

       • HUP - reload config file, app, and gracefully restart all workers

       • INT/TERM - quick shutdown, kills all workers immediately

       • QUIT - graceful shutdown, waits for workers to finish their current request before finishing.

       • USR1 - reopen all logs owned by the master and all workers See Unicorn::Util.reopen_logs  for  what  is
         considered a log.

       • 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.

       • WINCH - gracefully stops workers but keep the master running.   This  will  only  work  for  daemonized
         processes.

       • TTIN - increment the number of worker processes by one

       • TTOU - decrement the number of worker processes by one

       See  the  SIGNALS (http://unicorn.bogomips.org/SIGNALS.html) document for full description of all signals
       used by Unicorn.

RACK ENVIRONMENT

       Accepted values of RACK_ENV and the middleware they  automatically  load  (outside  of  RACKUP_FILE)  are
       exactly as those in rackup(1):

       • development - loads Rack::CommonLogger, Rack::ShowExceptions, and Rack::Lint middleware

       • deployment - loads Rack::CommonLogger middleware

       • none - loads no middleware at all, relying entirely on RACKUP_FILE

       All  unrecognized  values  for  RACK_ENV  are  assumed to be “none”.  Production deployments are strongly
       encouraged to use “deployment” or “none” for maximum performance.

       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.

       Note  the  Rack::ContentLength  and  Rack::Chunked  middlewares  are  also  loaded  by  “deployment”  and
       “development”,  but  no  other values of RACK_ENV.  If needed, they must be individually specified in the
       RACKUP_FILE, some frameworks do not require them.

ENVIRONMENT VARIABLES

       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.

AUTHORS

       The Unicorn Community <mongrel-unicorn@rubyforge.org>.