<!-- .slide: data-background="images/diego-ph-fIq0tET6llw-unsplash.jpg" class="vertical-center" style="padding: 1em 1em 1em 1em; color: white; background: rgba(0, 0, 0, 0.5); width: 90%; margin: auto;" --> # Kubernetes verstehen *Nicholas Dille, Haufe Group* <i class="fa-brands fa-docker" style="width: 1.5em; text-align: center;"></i> Docker Captain <i class="fa-brands fa-x-twitter" style="width: 1.5em; text-align: center;"></i> [@nicholasdille](https://twitter.com/nicholasdille) <i class="fa-brands fa-mastodon" style="width: 1.5em; text-align: center;"></i> [@nicholasdille@freiburg.social](https://freiburg.social/@nicholasdille)

<!-- .slide: class="center" --> ## Concepts

<!-- .slide: class="center" --> ## Imperative vs. declarative

<!-- .slide: class="center"--> ## Labels

## Lifecycle Applications require lifecycle management: - Deploy / remove - Upgrade / downgrade - Scale up / down - Restart ### Do not update pods directly Updating pods results in a container restart Essentially only the image can be updated

<!-- .slide: class="center"--> ## Architecture

<!-- .slide: class="center"--> ## Networking

## Self-hosted cluster Overlay networking, e.g. IP-in-IP encapsulation Nodes have routable and private IP addresses Pods/services have private IP addresses  <!-- .element: style="margin-top: 0.5em; width: 90%;" -->

## Managed cluster (cloud) Flat network Nodes, pods and services have routable IP addresses Pods and services are directly accessible from outside the cluster Integration with cloud services possible

<!-- .slide: class="center"--> ## Accessing pods

## Load balancer ```yaml apiVersion: v1 kind: Service metadata: name: my-service spec: type: LoadBalancer ``` <!-- .element: style="float: right; width: 15em;" --> Special type for a `Service` Requires integration with cloud provider External load balancer is responsible for routing traffic to services Annotations are used to configure external load balancer Requires flat network instead of overlay network ### No demo Too much effort to setup :-(

## Summary <i class="fa-duotone fa-4x fa-lightbulb-on"></i> <!-- .element: style="float: right;" --> - <span class="fa-li"><i class="fa-duotone fa-tags"></i></span> Labels provide context and select resources - <span class="fa-li"><i class="fa-duotone fa-arrows-spin"></i></span> Pod lifecycle is managed my multiple resources - <span class="fa-li"><i class="fa-duotone fa-chart-network"></i></span> Kubernetes architecture allows for highly available setups - <span class="fa-li"><i class="fa-duotone fa-handshake-simple"></i></span> The Kubernetes API server is **the** central component - <span class="fa-li"><i class="fa-duotone fa-dungeon"></i></span> Ingress controllers provide access to services <!-- .element: class="fa-ul" style="line-height: 1.5em;" --> ### Upcoming events <span style="font-size: smaller;"> ~~2023-10-11: Kubernetes [verstehen](https://heise-academy.de/webinare/kubernetes1023_konzepte)~~ 2023-10-18: Kubernetes [automatisieren](https://heise-academy.de/webinare/kubernetes1023_continous-deployment) 2023-10-25: Kubernetes [überwachen](https://heise-academy.de/webinare/kubernetes1023_monitoring) 2023-11-03: Kubernetes [absichern](https://heise-academy.de/webinare/kubernetes1023_security) 2023-11-14: [ContainerConf](https://www.containerconf.de/): Workshop [GitLab CI](https://www.containerconf.de/veranstaltung-20671-0-ci-cd-mit-gitlab.html), Talk [OCI 1.1](https://www.containerconf.de/veranstaltung-21037-0-container-registries-als-generische-artefaktspeicher--was-oci-1.1-neues-bringt.html), Talk [Dependency Updates](https://www.containerconf.de/veranstaltung-21033-0-nie-wieder-veraltete-dependencies-wie-sich-sicherheitsluecken-von-selbst-schliessen.html) 2023-11-23 / 2023-11-30 / 2023-11-07: Workshops [GitLab Ops](https://heise-academy.de/schulungen/einfuehrung-in-gitlab) (1 day) and [GitLab CI](https://heise-academy.de/schulungen/cicd-gitlab) (2 days) </span>