module forever de #node.js: pour une production sure

Dans un post précédent j'ai évoqué le fonctionnement de Node.js. Il existe un module appelé 'forever' qui industrialise le lancement de script javascript pour Node.js.
L'installation se fait comme d'habitude par la commande

sudo npm -g install forever

Le résultat doit etre:


/usr/local/lib/node_modules/forever
├── pkginfo@0.2.3
├── timespan@2.0.1
├── watch@0.5.0
├── microtime@0.2.0
├── daemon@0.4.1
├── node-fork@0.4.2
├── nssocket@0.3.7 (eventemitter2@0.4.8 lazy@1.0.8)
├── cliff@0.1.7 (colors@0.6.0-1 eyes@0.1.7)
├── portfinder@0.2.1 (mkdirp@0.0.7)
├── optimist@0.2.8 (wordwrap@0.0.2)
├── broadway@0.1.13 (colors@0.6.0-1 eventemitter2@0.4.8 optimist@0.3.1)
├── minimatch@0.0.5 (lru-cache@1.0.5)
├── utile@0.0.10 (async@0.1.18 mkdirp@0.3.0 rimraf@1.0.9 ncp@0.2.5)
├── flatiron@0.1.14 (director@1.0.9-1 optimist@0.3.1 prompt@0.1.12)
├── nconf@0.5.1 (async@0.1.18 ini@1.0.2 optimist@0.3.1)
├── ps-tree@0.0.2 (parse-table@0.0.0)
└── winston@0.5.10

Le lancement d'un programme par forever est très simple :

forever start 'monprogramme.js'

Exemple :(commande start et list)

 forever start cluster1.js

info:   Forever processing file: cluster1.js

german@german-1001PX:~$

german@german-1001PX:~$ forever list

info:   Forever processes running

data:       uid  command script      forever pid  logfile                        uptime     

data:   [0] YJVa node    cluster1.js 2857    2858 /home/german/.forever/YJVa.log 0:0:0:7.882

Si le programme lancé par forever vient à tomber, il  sera relancer automatiquement.

Forever est lui même en mode daemon (on peut fermer son terminal de lancement) 

L'aide sur forever est la suivante:

	german@german-1001PX:~$ 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
	--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.
	--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
	-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

view raw forever.txt hosted with ❤ by GitHub

L'article http://blog.nodejitsu.com/keep-a-nodejs-server-up-with-forever et le site de forever complètent mon propos.
Sur stackoverflow : un exemple d'usage de forever à l'intérieur d'un programme.