Support reading from symlinked files and dirs

[poblahblahblah]

Our current git2consul repo has the following structure:

production_uw1
production_ue1
staging_stg1
staging_stg2
staging_stg3

Our repos section of our git2consul config looks like this:

  "repos" : [{
    "name" : "git",
    "branches" : ["master"],
    "include_branch_name" : false,
    "source_root" : "staging_stg1",
    "url" : "[email protected]:goldstar/consul_data.git",
    "hooks": [{
      "type" : "polling",
      "interval" : "1"
    }]
  }]

The directory in the git repo that gets synced to /git in consul depends on what environment git2consul and consul are in. So if we're in the production uw1 AZ, then production_uw1 will get synced to /git in consul. This pattern has held up well so far, although we've recently been needing to introduce some data that would be shared across all environments.

We tried to add in a symlink like so:

global/foo/bar
production_uw1
...
staging_stg1/global -> ../global
...

We we're hoping this would work. It didn't. Admittedly this is kind of gross.

Version: 0.12.11
Error:

{"name":"git2consul","hostname":"ops.stg1.goldstarbeta.com","pid":27121,"level":50,"msg":"Failed to create repos due to Failed to load repo git due to Some consul updates failed:\nFailed to read key /var/lib/git2consul/cache/git/test-symlink/staging_stg1/global due to Error: EISDIR: illegal operation on a directory, read","time":"2016-10-13T19:58:39.759Z","v":0}

edit: I wanted to add that we worked around the issue, although I would still expect it to support symlinks, if at all possible. New configuration:

  "repos" : [
    {
      "name" : "git",
      "branches" : ["master"],
      "include_branch_name" : false,
      "source_root" : "staging_stg1",
      "url" : "[email protected]:goldstar/consul_data.git",
      "hooks": [{
        "type" : "polling",
        "interval" : "1"
      }]
    },
    {
      "name" : "git/global",
      "branches" : ["master"],
      "include_branch_name" : false,
      "source_root" : "global",
      "url" : "[email protected]:goldstar/consul_data.git",
      "hooks": [{
        "type" : "polling",
        "interval" : "1"
      }]
  }]