Note on file sharing for OS X

[Lewis John McGibbney]

After configuring config/database.yml and config/application.yml and executing ./bin/setup after a lot of std output I get the following...

== Preparing database (development and test environments) ==
    $ docker-compose run web bundle exec rake db:setup
      -> Creating network "earthdata-search_default" with the default driver
      -> Pulling db (postgres:)...
      -> latest: Pulling from library/postgres
Creating earthdata-search_db_1 ... error
      ->
      -> ERROR: for earthdata-search_db_1  Cannot start service db: b'Mounts denied: \r\nThe path /usr/local/earthdata-search/tmp/db\r\nis not shared from OS X and is not known to Docker.\r\nYou can configure shared paths from Docker -> Preferences... -> File Sharing.\r\nSee https://docs.docker.com/docker-for-mac/osxfs/#namespaces for more info.\r\n.'
      -> ERROR: for db  Cannot start service db: b'Mounts denied: \r\nThe path /usr/local/earthdata-search/tmp/db\r\nis not shared from OS X and is not known to Docker.\r\nYou can configure shared paths from Docker -> Preferences... -> File Sharing.\r\nSee https://docs.docker.com/docker-for-mac/osxfs/#namespaces for more info.\r\n.'
      -> Encountered errors while bringing up the project.
Exiting: Error executing command docker-compose run web bundle exec rake db:setup

By default, Docker for Mac shares directories falling under /Users, /Volumes, /private and /tmp anything else needs to be explicitly configured within the Docker daemon. In my case the EDSC code resides within /usr/local
I think this is worthy of being be noted within the README... possibly we could introduce an installation FAQ's section.
wdyt?

[Mark Reese]

@lewismc I'm on board with that. All of the devs on EED that have gone through this process haven't had the issues you're having. In an ideal world, whatever it is that you need to do to get things running or special notes you think should be added to help folks out, you'd just submit as a PR. Of course we'll review... but the idea of having non-EED folks test this process is to actually get some contributions from those folks as well to test everything (setup and PR/review process). So please, feel free to add those notes as a PR.

[Lewis John McGibbney]

I've added the following. I'll update the README in a new PR.
https://github.com/nasa/earthdata-search/wiki/FAQ's