Deploy policies for Vault
Summary:
This change focus to provide a framework to define and deploy policies,
and focus to integrate Salt and Vault.
The Salt primary server has a salt_primary policy to be able
to generate token with specific policies for other nodes.
Nodes receive policy for the exact paths of credentials they need,
as the ops/secrets/ namespace is shared between Salt deployment
and application own needs.
Test Plan:
vault policy list
salt-call vault.read_secret on various nodes, to check they can access theirs
but not others. Salt correctly log in with a permission allowing to create more
tokens with salt-node-* policy, and assign the correct one to each node.
Reviewers: dereckson
Reviewed By: dereckson
Differential Revision: https://devcentral.nasqueron.org/D2638