forever
A simple CLI tool for ensuring that a given script runs continuously (i.e. forever).
Installation
$ [sudo] npm install forever -g
Note: If you are using forever programatically you should install forever-monitor.
$ cd /path/to/your/project$ [sudo] npm install forever-monitor
Usage
There are two distinct ways to use forever: through the command line interface, or by requiring the forever module in your own code. Note: If you are using forever programatically you should install forever-monitor.
Using forever from the command line
You can use forever to run any kind of script continuously (whether it is written in node.js or not). The usage options are simple:
$ forever --help
usage: forever [action] [options] SCRIPT [script-options]
Monitors the script specified in the current process or as a daemon
actions:
start Start SCRIPT as a daemon
stop Stop the daemon SCRIPT
stopall Stop all running forever scripts
restart Restart the daemon SCRIPT
restartall Restart all running forever scripts
list List all running forever scripts
config Lists all forever user configuration
set <key> <val> Sets the specified forever config <key>
clear <key> Clears the specified forever config <key>
logs Lists log files for all forever processes
logs <script|index> Tails the logs for <script|index>
columns add <col> Adds the specified column to the output in `forever list`
columns rm <col> Removed the specified column from the output in `forever list`
columns set <cols> Set all columns for the output in `forever list`
cleanlogs [CAREFUL] Deletes all historical forever log files
options:
-m MAX Only run the specified script MAX times
-l LOGFILE Logs the forever output to LOGFILE
-o OUTFILE Logs stdout from child script to OUTFILE
-e ERRFILE Logs stderr from child script to ERRFILE
-p PATH Base path for all forever related files (pid files, etc.)
-c COMMAND COMMAND to execute (defaults to node)
-a, --append Append logs
-f, --fifo Stream logs to stdout
-n, --number Number of log lines to print
--pidFile The pid file
--sourceDir The source directory for which SCRIPT is relative to
--minUptime Minimum uptime (millis) for a script to not be considered "spinning"
--spinSleepTime Time to wait (millis) between launches of a spinning script.
--colors --no-colors will disable output coloring
--plain Disable command line colors
-d, --debug Forces forever to log debug output
-v, --verbose Turns on the verbose messages from Forever
-s, --silent Run the child script silencing stdout and stderr
-w, --watch Watch for file changes
--watchDirectory Top-level directory to watch from
--watchIgnore To ignore pattern when watch is enabled (multiple option is allowed)
--killSignal Support exit signal customization (default is SIGKILL),
used for restarting script gracefully eg. --killSignal=SIGTERM
-h, --help You're staring at it
[Long Running Process]
The forever process will continue to run outputting log messages to the console.
ex. forever -o out.log -e err.log my-script.js
[Daemon]
The forever process will run as a daemon which will make the target process start
in the background. This is extremely useful for remote starting simple node.js scripts
without using nohup. It is recommended to run start with -o -l, & -e.
ex. forever start -l forever.log -o out.log -e err.log my-daemon.js
forever stop my-daemon.js
There are several examples designed to test the fault tolerance of forever. Here's a simple usage example:
$ forever -m 5 examples/error-on-timer.js
Using forever module from node.js
In addition to using a Forever object, the forever module also exposes some useful methods. Each method returns an instance of an EventEmitter which emits when complete. See the forever cli commands for sample usage.
Remark: As of forever@0.6.0
processes will not automatically be available in forever.list()
. In order to get your processes into forever.list()
or forever list
you must instantiate the forever
socket server:
forever;
forever.load (config)
Synchronously sets the specified configuration (config) for the forever module. There are two important options:
- root: Directory to put all default forever log files
- pidPath: Directory to put all forever *.pid files
forever.start (file, options)
Starts a script with forever.
forever.startDaemon (file, options)
Starts a script with forever as a daemon. WARNING: Will daemonize the current process.
forever.stop (index)
Stops the forever daemon script at the specified index. These indices are the same as those returned by forever.list(). This method returns an EventEmitter that raises the 'stop' event when complete.
forever.stopAll (format)
Stops all forever scripts currently running. This method returns an EventEmitter that raises the 'stopAll' event when complete.
forever.list (format, callback)
Returns a list of metadata objects about each process that is being run using forever. This method is synchronous and will return the list of metadata as such. Only processes which have invoked forever.startServer()
will be available from forever.list()
forever.tail (target, options, callback)
Responds with the logs from the target script(s) from tail
. There are two important options:
length
(numeric): is is used as the-n
parameter totail
.stream
(boolean): is is used as the-f
parameter totail
.
forever.cleanUp ()
Cleans up any extraneous forever *.pid files that are on the target system. This method returns an EventEmitter that raises the 'cleanUp' event when complete.
forever.cleanLogsSync (processes)
Removes all log files from the root forever directory that do not belong to current running forever processes.
Run Tests
$ npm test