KubeCon + CloudNativeCon Europe 2020

When building services with etcd, one of the best features of etcd is watchers. It allows developers to create applications such that when a dataset is changed, the watcher for that dataset on another system receives the notification and performs user-specified action. A simple use case is a user has a program using etcd watchers to monitor the stock market and sell (user-defined action) if their stock of interest falls below price $X.

There are error failures that are not automatically covered with an etcd cluster such as network connectivity issues, DC outage, and cloud infrastructure maintenance. The talk consists of the following:
- what watchers are
- how to build your services using heartbeat key for monitoring etcd watchers
- perform locking on watchers to prevent race conditions
- caching data locally for your service to keep running until the etcd cluster is back up.

A very simple question but with many different answers when asked. Kubernetes should provide a ground set of concepts that allows interoperability of systems and a shared knowledge in the ecosystem. In any kubernetes distribution, a Pod or a Service have the same definition, this is not the case for application. As end-users are mainly managing apps, it's time for kubernetes to get a representation and a definition of it. 
The sig-apps community came to an agreement to provide this missing piece. They created a new Application resource and its controller. This talk is bringing light to this new upstream resource, the features it provides with concrete examples, and the next steps and how to get involved. 

What is a well-designed CLI?
How do we develop it?

Kubernetes is widely spread and people start to be interested in Day2 Operation. Along with this, the number of kubectl plugins is developed recently.

In this presentation, Aya Igarashi will talk about how to improve the design and develop a kubectl plugin based on her experience. She develops kubectl-bindrole which is a kubectl plugin that summarizes permissions for an RBAC account.
https://github.com/Ladicle/kubectl-bindrole

This session will be helpful for people who want to develop kubectl plugins, as well as for general CLI development.