script to spawn pm2 hangs

[caiguanhao]

If your pm2 is not runnig and you try to spawn pm2 from a script, it hangs. Abort the script and then run it again, it becomes normal.

pkill node         // kill pm2 process, in linux use: kill `pgrep pm2`
node app.js        // do not exit
                   // ctrl-c to abort
node app.js        // normal

app.js:

var spawn = require('child_process').spawn;
var pm2 = spawn('pm2', [ 'jlist' ]);
pm2.stdout.on('data', function(data) {
  process.stdout.write(data.toString());
});
pm2.stderr.on('data', function(data) {
  process.stderr.write(data.toString());
});
pm2.on('close', function(code) {
  console.log('exit code: ' + code);
});

please add support for pm2 to run from other script (for example, the Gruntfile.js).

node version: v0.10.24
pm2 version: v0.6.12
tested on mac & linux

[Unitech]

Yep, pm2 should be already daemonized before launching commands.

A ping method will be available on the 0.6.16, you should call it and wait for his answer before doing any operations with pm2. Is this approach okey for you ?

[caiguanhao]

If pm2 hasn't started yet, running the following code will not hang, but need to kill the process manually at the end of the code. I think pm2 --version would work just like pm2 ping in this example. This can be a temporary fix. Or pm2 should start with system login.

var spawn = require('child_process').spawn;
var ping = spawn('pm2', [ 'ping' ]);
ping.stdout.on('data', function(data) {
  var pm2 = spawn('pm2', [ 'jlist' ]);
  pm2.stdout.on('data', function(data) {
    process.stdout.write(data.toString());
  });
  pm2.stderr.on('data', function(data) {
    process.stderr.write(data.toString());
  });
  pm2.on('close', function(code) {
    console.log('exit code: ' + code);
    process.kill(ping);
  });
});

[tjwebb]

What is the command that needs to run prior to pm2 start ...? I am also having this issue.

EDIT: Running pm2 ping first seems to do the trick. It'd be great to have less insidious way of failing, though, than an error-less hang.