Re: Is anyone working on a CF CRD & Controller?

Zach Robinson

Hey Daniel,

Thanks for starting a convo. The timing couldn't be better. I can share some of the thinking going on in both CAPI and VMware land. 

But first and foremost I want to address the question: "Is there any point in the community working on such a solution, or are one of the bigger companies secretly working on something that would supersede any community effort?" - yes, yes, a thousand times yes to community collaboration!

The topic of CRDs is kind of huge. It's really great to hear your focus is on things like orgs/spaces. From a CAPI perspective, I've been thinking more about representing apps and push as CRDs, and I believe the Eirini team has some thoughts in this area as well. There's a lot of ground to cover clearly.

In terms of things that are in flight now.
  • Keshav kindly shared that networking is looking to provide Route CRDs.
  • Networking is also exploring providing Security Groups as CRDs.
  • CAPI is integrating kpack into CF to provide buildpack staging. This is done by generating kpack CRDs.
Currently these CRDs are being created and owned by the Cloud Controller, which enables us to present backward compatible APIs to our CLI and UI like stratos, while moving the implementation down into controllers fronted by CRDs.  There's an obvious potential to interact with k8s directly in the future, but the current use case is to be used by CC. Except for kpack which is an excellent stand alone tool already :).  

These efforts are great and are allowing us to begin a path towards using existing k8s tooling and projects to provide Cloud Foundry outcomes, but obviously there's a lot further to go.

From VMware's side, over the last couple weeks, there has been an effort to explore what it might look like to use CRDs entirely as a source of truth for *all* CF data, in place of a SQL database, as a learning exercise, not necessarily a desired outcome. The primary goal of that effort was to start the convo that we're having now, and to be able to contribute in a meaningful way.  Note there are no VMware-based plans to dump a fully fledged proposal. We need to start from a premise as a community of understanding how/why/and which resources are valuable as CRDs.

For example when we look at orgs/spaces - we have to wonder if those are even resources we want to represent as CRDs, when k8s already has a namespace construct.

I think we'll need to start some dedicated working document to collaborate in. I had planned on facilitating that after some of the investigation that VMware has wraps up, but I don't think that's a reason to hold off if you or somebody else in the community has thoughts they want to start getting down. CAPI and other teams can contribute to an existing doc if that makes sense. Any other thoughts you'd prefer for next steps?

Looking forward to a continued conversation.


On Wed, Apr 15, 2020 at 9:56 AM Keshav Sharma <ksharma@...> wrote:
Hi Daniel, 
The CF-K8s Networking team is currently working on a solution using Route CRDto introduce a “Route” custom resource and have Cloud Controller make/update these directly as part of the `cf map-route` and `cf unmap-route` workflows. Happy to discuss this further in our Cloud-Foundry Slack- #networking group. Regards, Keshav Sharma Product Manager | CF-K8s-Networking VMware

On Wed, Apr 15, 2020 at 3:01 AM Daniel Jones <daniel.jones@...> wrote:
Hi all,

In the spirit of community, I'm going to ask this question outright and in the open - is anyone (*looks at VMware MAPBU*) working on a CRD and accompanying controller for CF on Kubernetes?

Anyone with a non-trivial amount of Cloud Foundry experience knows that whilst the imperative interface of the CF CLI is great for exploratory work, it's far from ideal for production environments. I make a point of telling folks in CF training courses that no human should be using the CLI in production, other than for debugging.

A declarative interface for CF has always been desirable, and its omission is going to become even more stark once running CF on Kubernetes is the norm. We've had cf-mgmt which is close, but involves more steps than is ideal.

It'd be great to have one or more CRDs that represent the state of a Cloud Foundry, and accompanying controllers that converge upon that state. When I talk about state, I mean things like orgs, spaces, service broker registrations, service instances, roles and so on.

Four years ago I started work on a project called cf-converger to diff and converge a Cloud Foundry instance on a state declared in YAML. I got distracted with running a business and doing billable work, so whilst the concept was proven, it never really got to a state of usefulness. Plus, I seemed to spend half my coding time just writing excessively-verbose chained method calls on the official Java CF client :D 

I see such a solution as an inevitability in the Kubernetes-based future. Whilst I'm personally tempted to resurrect the project, it makes very little sense for a company like EngineerBetter to divert resources from billable work to a project that is needed, but can't be monetised.

Are any of the big players working on something similar? Is it something we should all be thinking and talking about? Is there any point in the community working on such a solution, or are one of the bigger companies secretly working on something that would supersede any community effort?

Daniel 'Deejay' Jones - CEO
+44 (0)79 8000 9153
EngineerBetter Ltd - More than cloud platform specialists

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