Data Bags - Secrets should not be read with IO.read() for Encrytped Data Bags

Follow up to thread at https://discourse.chef.io/t/reading-secret-for-encrypted-data-bag/11414/3

According to the data bags documentation, it should be possible to do this:

data_bag_item('bag', 'item', IO.read('secret_file'))

If the secret in the file secret_file contains trailing whitespace (ie. space or even just a simple new line '\n'!), then Chef (at least version 12.21.4 on Ubuntu 16.04) cannot decode. The encrypted data bag has been created like so:

$ knife data bag create my-data-bag secret_item --local-mode --config-option data_bag_path=./data_bags --secret-file ./.data_bags/secret_file

If the secret has been read with Chef::EncryptedDataBagItem.load_secret('secret_file') or IO.read('secret_file').strip, then it's possible for Chef to decode.

Thus: please change the data bags documentation to show only Chef::EncryptedDataBagItem.load_secret('secret_file').

Start at the data bags documentation section titled “load with recipe DSL,” linked in the issue, and review the example that reads the secret with IO.read(). Update the example to use Chef::EncryptedDataBagItem.load_secret('secret_file'), then verify the documentation no longer recommends IO.read() for encrypted data bag secrets.