unicorn_rails - unicorn launcher for Rails 1.x and 2.x users
unicorn_rails [-c CONFIG_FILE] [-E RAILS_ENV] [-D]
[RACKUP_FILE]
A rackup(1)-like command to launch ancient Rails (2.x and earlier)
applications using Unicorn. Rails 3 (and later) support Rack natively, so
users are encouraged to use unicorn(1) instead of unicorn_rails(1).
It is expected to be started in your Rails application root
(RAILS_ROOT), but the "working_directory" directive may be used in
the CONFIG_FILE.
The outward interface resembles rackup(1), the internals and
default middleware loading is designed like the script/server command
distributed with Rails.
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.
- -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". Daemonization will skip
loading of the Rails::Rack::LogTailer middleware under Rails >=
2.3.x. By default, unicorn_rails(1) will create a PID file in
"RAILS_ROOT/tmp/pids/unicorn.pid". You may override this
by specifying the "pid" directive to override this Unicorn
config file.
- -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 "development" or
"production".
- -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.
- -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.
- --path PATH
- Mounts the Rails application at the given PATH (instead of "/").
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.
- -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. For Rails >=
2.3.x, this loads the Rails::Rack::Debugger middleware.
- -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.
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
Rack::Builder DSL. Unlike many other Rack applications, RACKUP_FILE
is completely optional for Rails, but may be used to disable some of
the default middleware for performance.
Embedded command-line options are mostly parsed for compatibility
with rackup(1) but strongly discouraged.
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.
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.
The Unicorn Community <unicorn-public@yhbt.net>.