Internal Server Error when running workflow

[bigmstone]

When running workflow within flow we recieve a 500 response from ST2 API if the file has incorrect permissions. It would be a better UX if we returned a more appropriate return code and some metadata to display to the user to help them fix the issue easier.

Example ST2 API log which is easy to see what to do to fix it for us dev types: https://gist.github.com/bigmstone/1933abe6dd6a700ceb3b22b37c97e899

This might not be high enough priority to worry about, but putting it out there in case anyone agrees.

[LindsayHill]

Agreed that it would be better to throw a more user-friendly error. Seems to be pretty common for people to end up with files owned by root, which they then can't edit.

[bmomberger-bitovi]

I got burned on this recently when installing the examples pack. I recommend at least updating the quick start guide to include chown st2:st2 in installing examples

[LindsayHill]

@bmomberger-bitovi https://github.com/StackStorm/st2docs/pull/864