- Zero downtime code deployment
- Ability to change environment variables of workers with zero downtime
- Resuscitation - when a worker dies it is restarted
- Redirect worker stdout and stderr to rotating gzipped log files
- Runs as daemon, providing ability to start and stop
To use naught, your node.js server has 2 requirements.
-
Once the server is fully booted and is readily accepting connections,
process.send('online');
Usually this is done in the
listening
event for a node server, for example:server = http.createServer(...); server.listen(80, function () { if (process.send) process.send('online'); });
-
Listen to the
shutdown
message and shutdown gracefully. This message is emitted after there is already a newer instance of your server online and taking care of business:process.on('message', function(message) { if (message === 'shutdown') { performCleanup(); process.exit(0); } });
If your server has no long-lived connections, you may skip this step. However, note that most node.js apps do have long lived connections. In fact, by default, the connection: keep-alive header is sent with every request.
When you receive the
shutdown
message, either close all open connections or callprocess.exit()
.
If you want to deploy on a restricted port such as 80 or 443 without sudo, try authbind.
Note that there are 3 layers of process spawning between the naught CLI
and your server. So you'll want to use the --deep
option with authbind.
naught start [options] server.js [script-options]
Starts server.js as a daemon passing script-options as command
line arguments.
Each worker's stdout and stderr are redirected to a log files
specified by the `stdout` and `stderr` parameters. When a log file
becomes larger than `max-log-size`, the log file is renamed using the
current date and time, and a new log file is opened.
With naught, you can use `console.log` and friends. Because naught
pipes the output into a log file, node.js treats stdout and stderr
as asynchronous streams.
If you don't want a particular log, use `/dev/null` for the path. Naught
special cases this filename and disables that log altogether.
Creates an `ipc-file` which naught uses to communicate with your
server once it has started.
Available options and their defaults:
--worker-count 1
--ipc-file naught.ipc
--log naught.log
--stdout stdout.log
--stderr stderr.log
--max-log-size 10485760
--cwd .
--node-args ''
naught stop [options] [ipc-file]
Stops the running server which created `ipc-file`.
Uses `naught.ipc` by default.
This sends the 'shutdown' message to all the workers and waits for
them to exit gracefully.
If you specify a timeout, naught will forcefully kill your workers
if they do not shut down gracefully within the timeout.
Available options and their defaults:
--timeout none
naught status [ipc-file]
Displays whether a server is running or not.
Uses `naught.ipc` by default.
naught deploy [options] [ipc-file]
Replaces workers with new workers using new code and optionally
the environment variables from this command.
Naught spawns all the new workers and waits for them to all become
online before killing a single old worker. This guarantees zero
downtime if any of the new workers fail and provides the ability to
cleanly abort the deployment if it hangs.
A hanging deploy happens when a new worker fails to emit the 'online'
message, or when an old worker fails to shutdown upon receiving the
'shutdown' message. A keyboard interrupt will cause a deploy-abort,
cleanly and with zero downtime.
If `timeout` is specified, naught will automatically abort the deploy
if it does not finish within those seconds.
If `override-env` is true, the environment varibables that are set with
this command are used to override the original environment variables
used with the `start` command. If any variables are missing, the
original values are left intact.
Uses `naught.ipc` by default.
Available options and their defaults:
--override-env true
--timeout none
naught deploy-abort [ipc-file]
Aborts a hanging deploy. A hanging deploy happens when a new worker
fails to emit the 'online' message, or when an old worker fails
to shutdown upon receiving the 'shutdown' message.
When deploying, a keyboard interrupt will cause a deploy-abort,
so the times you actually have to run this command will be few and
far between.
Uses `naught.ipc` by default.
naught version
Prints the version of naught and exits.
naught help [cmd]
Displays help for cmd.