试图了解chef_vault和ruby的收藏

Question

I'm new to Ruby and Chef I'm having trouble understanding how to get nested elements out of a databag (chef_vault). I think this is more a fundamental Ruby question, but not sure if somewhat Chef specific.

I created this vault:

$json = '{
 "KEY1": [{
  "SUBKEY1": "aaaaa",
  "SUBKEY2": "bbbbbbb",
  "SUBKEY3": "cccccccc"
 }],
 "KEY2": [{
  "SUBKEY1": "dddddd",
  "SUBKEY2": "eeeeee"
 }],
 "KEY3": "fffffff",
 "KEY4": "ggggggg"
}'

knife vault create test_vault vaultitem1 $json --admins red888 --mode client --search 'role:testservers'

Here is what I noticed when trying to get nested elements out of it in my recipe:

test_vault = ChefVault::Item.load("test_vault", "vaultitem1")

puts test_vault.class
puts test_vault['SUBKEY1'].class
puts test_vault['SUBKEY1'].inspect
puts test_vault['SUBKEY1'][0]['SUBKEY2']

Now what I see in the console:

ChefVault::Item
Array
[{"SUBKEY1"=>"aaaaa", "SUBKEY2"=>"bbbbbbb", "SUBKEY3"=>"cccccccc"}]
{"SUBKEY1"=>"aaaaa", "SUBKEY2"=>"bbbbbbb", "SUBKEY3"=>"cccccccc"}
bbbbbbb

Originally I tried test_vault['KEY1']['SUBKEY2'] which gave me an error. My question is, why must I do test_vault['KEY1'][0]['SUBKEY2'] what am I indexing into with [0]?

Answer 1

KEY1 and KEY2 are both arrays containing a single hash. That's how you set up the JSON so that's how you have to use it. Not really a Ruby thing.