Writing Kube Controllers for Everyone

With the introduction of Custom Resource Definition, as well as external API servers everyone is now able to create its own resources and store them inside kubernetes cluster. But that is only half of …

With the introduction of Custom Resource Definition, as well as external API servers everyone is now able to create its own resources and store them inside kubernetes cluster. But that is only half of the work that needs to be done. During this presentation Maciej, who co-authored both Job and CronJob controllers, and is a frequent reviewer of controller and apiserver-related code will guide you through basic set of steps that are necessary to write a simple controller. As an example he will discuss his recent work around improving CronJob controller, as well as introduce the 11 rules that needs to be fulfilled when writing a good controller.Topics to be covered include:1. How controllers work, loop over:* monitor resources* react to changes2. Shared Informers.3. Owner references.4. Emitting status.5. Handling errors.