RFC: Makes salt minion's master_port and publish_port options depend on each master's ip

[kstreee]

• Feature Name: Makes salt minion's master_port and publish_port options depend on each master's ip.
• Start Date: 2018-11-07
• RFC PR:
• Salt Issue:

Summary

For example, current salt minion configuration can't cover the following setting of multi-master.

master1's config

 interface: 1.1.1.1
 ret_port: 30001 
 publish_port: 30002

master2's config

 interface: 1.1.1.2
 ret_port: 30008
 publish_port: 30009

minion's config

master:
  1.1.1.1:30001
  1.1.1.2:30001
publish_port: ?

Motivation

We are trying to deploy salt master using kubernetes, and kubernetes-like systems allocate network resources highly dynamically to use the limited resources efficiently. To leverage the system's network environment (dynamically allocate ports to expose container's ports to the outer network), publish_port and ret_port of salt masters of a multi-master environment can be assigned as different ports like the above setting.

Design

Current salt minion's master config

master:
  1.1.1.1:RET_PORT (MASTER_PORT)
  1.1.1.2:RET_PORT (MASTER_PORT)
publish_port: PUBLISH_PORT

Desired salt minion's master config

master:
  - host: 1.1.1.1
    master_port: 30001
    publish_port: 30002
  - host: 1.1.1.2
    master_port: 30008
    publish_port: 30009

Alternatives

Giving up multi-master setting which uses different ports for the same purpose..?

Unresolved questions

Not sure... how to find all being affected points in the minion code?

Drawbacks

• Backward compatibility, how to support both formats (old format, and new format) of master connection information of salt minion config?
• Implementation cost, we should find all being affected points in the minion code, and patch it to accept the new form of salt master connection config.
• Documentation

[dwoz]

@kstreee Thanks for the feature request. It makes sense to me and I like it.. @core-team comments?

[isbm]

What's wrong would be just adding the publish_port instead?

master:
  - [2001:0db8:85a3:0000:0000:8a2e:0370:7334]:3001
    publish_port: 3002
  - 123.123.123.123:3001
    publish_port: 3002
  - foo.bar.blah.com:3001
    publish_port: 3002
  - publish_port: 3002  # Default port

[isbm]

Second, this have to be an RFC pull request, not an issue. Please close the issue and rewrite this as an RFC, and make a PR so we can discuss it there.

[kstreee]

@isbm Sure, I would rather change the pr what I sent as a RFC. When I opened this issue, I thought to add this feature might be tricky so I opened this issue to discuss before providing sample code of this RFC. But, I realized it isn't tricky at all after dived into the code, so to show an example and modification points of this RFC, sent the pr. As your advice, closed this issue. Please move your comment to the pr here #50521 to discuss about that (and I think it is a good point and we should talk about that more). Thanks for the guiding me.