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

Provided by: unicorn_5.5.3-1build1_amd64

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 (https://yhbt.net/unicorn/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.

       UNICORN_FD  is  a  comma-delimited  list of one or more file descriptors used to implement
       USR2 upgrades.  Init systems may  bind  listen  sockets  itself  and  spawn  unicorn  with
       UNICORN_FD set to the file descriptor numbers of the listen socket(s).

       As  of unicorn 5.0, LISTEN_PID and LISTEN_FDS are used for socket activation as documented
       in the sd_listen_fds(3) manpage.  Users relying on this feature do not need to  specify  a
       listen socket in the unicorn config file.

AUTHORS

       The Unicorn Community <unicorn-public@yhbt.net>.