如何在微服务架构中管理MySQL连接

I have the gist of how to connect to a MySQL server, however my dilemma is using passwords. Here are some of the things I am looking at.

  1. Architecture will be 1 core service which as of right now will be set up as a digest authentication service. Note: In the future I will also have it set up for kerberos authentication.
  2. The service will have a schema it will need to be able to access in MySQL. Also the micro services will have their own schemas that they will also need to be able to access.
  3. The database will be localhost initially but will eventually be moved (in production) to a separate server altogether.

Given the requirements above, I cannot give the services users that are restricted to localhost and have no password associated with them (nor would I want that in the event the server was hacked). So how can I have access to the database without using any plain text passwords (I don't want it stored in the code)?

Maybe I am just not understanding something here that could make my life so much easier so again I look towards the wisdom of the many here. Thanks in advance!

Some things that I should maybe mention: I plan on using go-martini as my http router, I'd like to be able to set up OAuth Provider, I will need to manage user sessions and authentication (right now not as important as I'm trying to get the core part of the service setup)

Edit: To clarify some information;

  1. I do not have an AD, kerberos, or any other LDAP service to use and would be hard pressed to set them up at this time in a VM I use for development.
  2. The service should not be dependent on any of those items as SSO is a much later requirement in this project.
  3. Strictly speaking it will be deployed in environments where there are none of those available and this is non-negotiable.
  4. I also am specifically developing the services in Go and the clients in React.

Note: I do not need someone to correct MY question. I would appreciate it if you do not change the context of my question to suite the answer you wish to give me. That is not what StackOverflow is about, it is also quite rude to do that. Thank you.