Re: Operator Framework questions
On Sat, Oct 12, 2019 at 11:24 AM Gareth Rushgrove <gareth@...> wrote:
On Fri, 11 Oct 2019 at 13:08, Daniel Messer <dmesser@...> wrote:Hi Gareth,sorry for the late reply - responding inline. Thanks for the questions - keep them coming!On Wed, Oct 9, 2019 at 6:22 PM Gareth Rushgrove <gareth@...> wrote:Thanks for the presentation, I had a few questions and thought I'd
kick things off here.
Terminology wise, checking this is still the canonical definition from
a concept point of view?
I know there are several tools which help build operators
(kubebuilder, KUDO, kopf etc.), I wanted to ask about compatibility.
From a developers point of view these are all different obviously, but
what about from an end users perspective?
I think this definition is still valid. An Operator is a custom controller with its own CRDs serving as the user interface (exceptions exist).The Framework is designed to be open to the way the Operator itself is built. The packaging format and OLM don't depend on the SDK.However there is of course good integration between the SDK and OLM.
2. Relationship to Operator Hub
Chris also mentioned the intent to move the Operator Hub to CNCF in
https://github.com/cncf/toc/pull/303. Do you see that being under the
Operator Framework project, or under a standalone project? I think
that's interesting given the generic nature of Operators (as I
understand them above) and the Operator Framework as a specific tool.
For instance, can a kopf operator be added to Operator Hub today?
It is under the Framework: https://github.com/operator-framework/operatorhub.ioAnd yes, a kopf operator, or a kubebuilder operator, or KUDO or something entirely custom can be added to this. They enabling part is the packaging format that drives the indexing and visual display.Are there any examples of non-operator-framework operators on Operator Hub today?
There are lots of Operators that are not written with the SDK there. Every Operator on OperatorHub.io however is packaged for OLM to enable the visual display, versioning and install instructions.
Examples are Strimzi Kafka, Synposys, AWS Service Operator or Spark.
3. Relationship to Helm
As Helm is a fairly well established CNCF project, I'd be interested
in the relationship between the Operator Framework and Helm. How
involved are the Helm maintainers in the integration with the Operator
The Operator SDK project maintainers collaborate with the Helm maintainers, primarily on the Helm-based Operator pattern the SDK provides.Helm in general focusses on Day 1 operations: bundle & install using an external tool. Operators include that and put emphasis on Day 2 operations: orchestrated updates, complex re-configuration without re-deploying from scratch, backup / restore, failover / failback, etc with kubectl. Helm serves stateless applications very well, that can be entirely maintained using the built-in functionality in k8s. Operators serve those too but provide an evolution to templating package manifests by extending the built-in k8s functionality, thus enabling k8s to run stateful applications and advanced, distributed systems.Regarding the Operator Hub point as well. One thing I feel we should
strive to avoid plays out in my mind like:
User: Where do I find applications I can install on my Kubernetes cluster?
Helpful internet person (HIP): Why type of applications are you using?
HIP: Helm or Operators?
HIP: Never-mind, do to Helm Hub and Operator Hub
User: Thanks! I presume these come from two different organisations?
HIP: Oh, no, both are CNCF projectsI get this sentiment. I think it's important to point out that Operators and Applications are different concepts. I'd like to think of Operators as managed service providers to get managed instances of applications. So the question a user would be asking instead: do I want to enable my cluster to serve me that application and manage it or do I want to run it myself?Thanks for the answers.I think it's fine for producers of applications to appreciate those technical different concerns, but nearly no end user is doing to ask such a complex question - they just want to run (say) MySQL.
I think there are nuances here. For a development environment that may be true, but for someone who's responsible for running a production workload based on MySQL it's going to make a big difference whether they end up being responsible for the entire database lifecycle or can defer that to a piece of software or a service.
I definitely think it would be good to talk about application stores in general in the SIG, and include folks from Helm and other operator developer tooling. I'd love to hear from maintainers of Helm and other operator tools what they think.Gareth
I know their are benefits to different tools and approaches under the
CNCF banner, but when it comes to generic descriptions (Applications!)
and end user distribution it's probably worth a conversation between
multiple projects.Yes, agreed!
He / Him / His
Product Manager OpenShift
70563 Stuttgart--Gareth Rushgrove
He / Him / His
Product Manager OpenShift