Simple example that uses Vault's Go client library to interact with Vault and read secrets. The secret key is "hello" and the value is "world" as show below using the CLI.
$ vault kv get secret/foo
====== Metadata ======
Key Value
--- -----
created_time 2018-10-29T01:16:21.500198665Z
deletion_time n/a
destroyed false
version 1
==== Data ====
Key Value
--- -----
hello world$ vault kv get -field=hello secret/foo
world