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.
SEE ALSO¶
- •
- unicorn_rails(1)
- •
- Rack::Builder ri/RDoc
- •
- Unicorn::Configurator ri/RDoc
- •
- Unicorn RDoc (http://unicorn.bogomips.org/)
- •
- Rack RDoc (http://rdoc.info/gems/r#/gems/rack/frames)
- •
- Rackup HowTo (http://wiki.github.com/rack/rack/tutorial-rackup-howto)
AUTHORS¶
The Unicorn Community <unicorn-public@bogomips.org>.