Skip waiting for MongoDB if not installed or configured.

[abernix]

MongoDB is no longer an absolute requirement of all Meteor applications and can be optionally removed.

This adds a guard that skips the polling and waiting for Mongo to become available if either the 'mongodb' module is not present, or if the 'MONGO_URL' environment variable
is unset.

Full-disclosure, I coded this entirely in the GitHub editor, but I suspect it should
work well. I'm not sure the best way to test this from the checkout though. 😉

[GeoffreyBooth]

MongoDB is no longer an absolute requirement of all Meteor applications and can be optionally removed.

Do you have a citation for this?

I'm working on a refactor that splits entrypoint.sh into several scripts, so that the child scripts can be overridden without needing to override everything. As part of that, I’ll update the “check Mongo” script so that it’s only run if MONGO_URL is set. I think that's a good way to control it. This refactor also adds tests.

[abernix]

It became possible some time before the introduction of the --minimal flag in Meteor 1.7, but was very much made simpler by the flag itself:

• https://github.com/meteor/meteor/blob/devel/History.md#v17-2018-05-28
• meteor/meteor@590ca4d

[abernix]

Your plan sounds great, and leveraging MONGO_URL is probably more than sufficient, so feel free to close this!