[RFC #0001] Supporting service bindings used during staging

[cloudfoundry]

[RFC #0001] Supporting service bindings used during staging

[piyalibanerjee]

@tcdowney -- that part is unclear now since we don't know exactly how the new kpack service bindings will track the status of the bindings. We will know more once the new kpack binding is released in 3-6 weeks.

[tcdowney]

@jspawar you'll be happy to know the dream lives on: cloudfoundry/korifi#463

[njbennett]

Updated this to remove WIP status, reflect our latest thinking. We expect to be picking this work up in about a month.

[mkocher]

I understand* the need for build packs to know which services are bound to an application, but it has always bothered me that a build process would be given live credentials. I’d like to see this change result in build packs being given the bound services without credentials to them.

• I’ve never really liked it though, and think it represents some debt. Push-then-bind results in a different output than bind-then-push. So it’s something a developer has to know that is not obvious. Maybe this got better in v3? My mental model is still v2 based.

[tcdowney]

When the service binding /create endpoint is hit, CAPI will create a Service Binding resource. The controller will call back to CAPI with the state of that service binding whenever it changes.

Can we elaborate on what this means? What state changes will the controller be tracking and what will Cloud Controller need to be aware of?

[njbennett]

@mkocher

That's a really interesting point. And I think should be technically possible. The buildpack detect scripts key off of the service binding's type. We'll have to look into what other information they need and under what circumstances.

As far as I know the big thing that service-bind-at-build-time enables modifying the Java startup command with configuration necessary to connect to an agent, which is a common pattern for monitoring. Maybe there's another place besides staging where we could modify startup commands (and provide agent binaries) but that seems out of scope for this particular conversation. Might be worth recording in the RFC though because no one on the team understood this in detail when we started this exploration.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/175157137

The labels on this github issue will be updated when the story is started.

[bosh-admin-bot]

This issue was marked as Stale because it has been open for 21 days without any activity. If no activity takes place in the coming 7 days it will automatically be close. To prevent this from happening remove the Stale label or comment below.

[jspawar]

@tcdowney wowow, good job y'all