add ENV['USER'] to freeform tags

[slippman]

@stephenpearson , what do you think of adding a freeform tag that identifies the user who created the instance? This may make it easier to search for instances that a specific user created. I am currently handling it like this:

hostname_prefix: gta-<%= ENV['USER'] %>

but in the case where someone decides to change that, it might be hard for them to find their node.
Maybe we can add a freeform tag like owner, or created_by, or something like that?

[stephenpearson]

Hi @slippman. Sorry for the delay in getting back to you. I'm a little reluctant to add a myriad of tag options unless we can be sure that most users would want that by default. Does something like this not work for you instead?

platforms:
  - name: foo
    driver:
      freeform_tags:
        username: "<%= ENV['USER'] %>"

[slippman]

Yes, that ended up working great. Thanks! Closing issue..