Launch multiple instances with Grunt

[kcampion]

It would be great to have this feature in the next version.

Problem
I had this error when I launched multiple instances of different webapps:

Running "watch" task
Waiting...
Fatal error: Port 35729 is already in use by another process.

Solution
The solution is to use a random port number for watch and express' debug. I have only tested it under dev zone. The port number for debug is random, it's possible to have an error because Grunt initializes the same.

Install grunt-openport (https://github.com/shama/grunt-openport)

# npm install grunt-openport --save-dev

Add "dev_port" and "opts" under dev into Gruntfile.js

grunt.initConfig({
    express: {
      options: {
        port: process.env.PORT || 9000
      },
      dev: {
        options: {
          script: 'server/app.js',
          debug: true,
          dev_port: true,
          opts: ['--debug=<%= express.dev.options.dev_port %>']

And add all "openport" into the "serve" task:

grunt.registerTask('serve', function (target) {
    if (target === 'dist') {
      [...]
    }

    if (target === 'debug') {
      [...]
    }

    grunt.task.run([
      'openport:express.dev.options.dev_port:5860:5960',
      'openport:watch.livereload.options.livereload:35729:36729',
      'openport:watch.express.options.livereload:35729:36729',
      'clean:server',
      [...]

Update the file server/config/local.env.js with:

module.exports = {
  DOMAIN: 'http://localhost:' + (process.env.PORT || 9000),

Now

# cd /my_project1 && PORT=9001 grunt serve
# cd /my_project2 && PORT=9002 grunt serve

[Awk34]

I think a better solution might be to just set the debug ports in the server's grunt config to a random port at generation-time. How does that sound?

[kcampion]

What do you mean @Awk34? This is what I do with these modifications.

[Awk34]

So the problems here are that the Express server always defaults to port 9000, and livereload uses the default 35729 port. Both of these ports can be set statically. We could randomize the livereload port and dev port when someone runs the generator. That way if you go and scaffold out two different projects, you can grunt serve them immediately without modifying anything. This solution would also prefent adding more cruft to the final project.

[kcampion]

As you want, I proposed this solution to avoid changing the server's grunt config.

[Awk34]

Closing in favor of #957