Allow location of settings.json to be overridden through cli arg

[jhollinger]

Resolves issue #195, allowing the location of the settings file to passed as a parameter. The following should all work:

bin/run.sh --settings settings2.json
bin/run.sh --settings /abs/path/to/settings.json
node server.js --settings my_settings.json
...

Unfortunately this adds a dependency (optimist) that converts cli args into a hash object. However that should make adding other options quite simple in the future.

[Pita]

good idea, we just need to document that somewhere so we don't forget about this feature

[fourplusone]

I think a --help / -h flag would be a good place for documenting startup parameters

[Pita]

@fourplusone thats right if you have lots of command line parameters, but so far we have only one, and this one is optional

[jhollinger]

Even though there's currently only one option, IMHO -h/--help is a sensible place to "document" it. People expect to find things that way. And I bet more will be added over time.

[fourplusone]

I would suggest to handle the command line parameters in its own module. See: fourplusone@fa15d7a

[jhollinger]

Almost seems overkill at this point, but I guess it is a little cleaner, especially if we add more options.

If we do add a -h/--help option, bin/run.sh should detect and send it to server.js immediately, and never call bin/installDeps.sh, etc.

[fourplusone]

If there are missing deps skipping installDeps.sh will cause a crash, even if the user only wants to read --help

[jhollinger]

IMO waiting on installDeps, just to see -h/--help is super annoying. It can take awhile. And it prints out lots of junk.

@fourplusone You're right about missing deps = crash, but we can get around that. The simplest way would be to keep your Cli module, but strip out optimist. (It's not too difficult to manually parse process.argv.slice(2)). Then if that module is loaded first, since it has no deps, it can print --help and exit.

[jhollinger]

This latest commit incorporates some of @fourplusone's ideas, but removes optimist, so that -h/--help can be run before any dependencies are ever installed.

If the idea is accepted, the commit history probably needs to be cleaned up.

[Pita]

A wiki article called "how to pass the settings file via command line" would have been enough imho

[jhollinger]

@Pita should I revert the -h/--help changes? I was curious how it would play out. But with only one option, I could go either way.

[jhollinger]

I am closing this in light of pull request #478.