Getting Started with Kubernetes - 30min

This is the 30 minute version without a demo of Getting Started with Kubernetes.

If you’re working with just a few containers, managing them is not too complicated. But what if you have hundreds or thousands? Think about having to handle multiple upgrades for each container, keeping track of container and node state, available resources, and more. That’s where Kubernetes comes in. Kubernetes is an open source container management platform that helps you run containers at scale. This talk will cover Kubernetes components.

Transcript

1. Getting Started with Kubernetes Tiffany Jernigan Senior Developer Advocate VMware tiffanyfayj
2. T I F F A N Y F A Y J People started containerizing applications
3. T I F F A N Y F A Y J Containers made it easy to build and scale cloud-native applications
4. T I F F A N Y F A Y J People needed an easier way to manage large clusters with many containers
5. T I F F A N Y F A Y J T I F F A N Y F A Y J
6. T I F F A N Y F A Y J
7. T I F F A N Y F A Y J ON-PREMISES CLOUD KUBERNETES CAN BE RUN ANYWHERE
8. CONCEPTS T I F F A N Y F A Y J
9. T I F F A N Y F A Y J CLUSTER ARCHITECTURE kubernetes.io/docs/concepts/architecture
10. T I F F A N Y F A Y J NODES • When you deploy Kubernetes, you get a cluster. These clusters consist of nodes. • Virtual or physical machines • Node Types • Control Plane • Worker kubernetes.io/docs/concepts/overview/components
11. T I F F A N Y F A Y J NODES API server controller manager scheduler etcd cloud controller manager kubelet kube-proxy container runtime control plane worker
12. T I F F A N Y F A Y J CONTROL PLANE API server controller manager scheduler etcd cloud controller manager
13. T I F F A N Y F A Y J WORKER NODES kubelet kube-proxy container runtime
14. T I F F A N Y F A Y J WORKLOADS
15. T I F F A N Y F A Y J WORKLOADS Pods • Basic execution unit of a Kubernetes application • Will not reschedule on failure Deployment • Allows scaling, rolling updates, rollbacks • Delegates pod management to ReplicaSets ReplicaSet • Maintains a stable set of replica Pods running at any given time
16. T I F F A N Y F A Y J WORKLOADS StatefulSet • Used to manage stateful applications • Manages deployment DaemonSet • Creates an instance of a pod on each worker node Job • Runs pod(s) until completion CronJob • Creates Jobs on a repeating schedule
17. T I F F A N Y F A Y J SERVICES kubernetes.io/docs/concepts/services-networking
18. T I F F A N Y F A Y J SERVICES • Services give us a stable endpoint to connect to a pod or a group of pods • Maps a fixed IP address to a logical group of pods • Different types: • ClusterIP, NodePort, LoadBalancer, ExternalName • There are more kinds and flavors of services, but we won’t get into those today
19. T I F F A N Y F A Y J BASIC SERVICE TYPES • ClusterIP (default) • A virtual IP address is allocated for the service (internal private range) • This IP is only reachable from inside the cluster • NodePort • Port allocated for the service (in 30000-32767 range) • Port is available on all node • LoadBalancer • External LB allocated (typically a cloud LB) • Typically costs a little money
20. T I F F A N Y F A Y J NETWORKING kubernetes.io/docs/concepts/services-networking
21. T I F F A N Y F A Y J KUBERNETES NETWORK MODEL • TL;DR: our cluster (nodes and pods) is one big flat IP network • In detail: ⁃ all nodes must be able to reach each other, without NAT ⁃ all pods must be able to reach each other, without NAT ⁃ pods and nodes must be able to reach each other, without NAT ⁃ each pod is aware of its IP address (no NAT) • Kubernetes doesn't mandate any other particular implementation
22. T I F F A N Y F A Y J CONTAINER NETWORK INTERFACE (CNI) • When a pod is created, Kubernetes delegates the network setup to CNI plugins (it can be a single plugin, or a combination of plugins, each doing one task) • Has a well-defined specification for network plugins https://github.com/containernetworking/cni/blob/master/SP EC.md#network-configuration
23. T I F F A N Y F A Y J INGRESS
24. T I F F A N Y F A Y J CONFIGURATION kubernetes.io/docs/concepts/configuration
25. T I F F A N Y F A Y J CONFIGURATION • ConfigMaps • Stores data as key-value pairs • Allows you to decouple environment-specific configuration from your container images • Secrets • Store and manage sensitive information
26. T I F F A N Y F A Y J SECURITY kubernetes.io/docs/concepts/security/
27. T I F F A N Y F A Y J SECURITY • Namespaces • Service accounts • Role-based access control (RBAC) • Secrets • And there’s a lot more • https://kubernetes.io/docs/reference/access-authn-authz/
28. T I F F A N Y F A Y J COMMUNICATION WITH K8S API • kubectl • CLI tool used to interface with the Kubernetes API • ~/.kube/config • kubeconfig file is used for securely accessing your cluster
29. T I F F A N Y F A Y J SOME OTHER THINGS TO LOOK INTO • Volumes • Autoscaling • Role-based access control (RBAC) • Load Balancing • Custom Resource Definitions (CRD) • Ingress controllers
30. T I F F A N Y F A Y J A FEW TOOLS TO MANAGE STACKS • Shell scripts invoking kubectl • YAML resource manifests committed to a repo • Kustomize (YAML manifests + patches applied on top) https://github.com/kubernetes-sigs/kustomize • Helm (YAML manifests + templating engine) https://github.com/kubernetes/helm • Carvel https://carvel.dev/
31. T I F F A N Y F A Y J LINKS AND RESOURCES • https://kubernetes.io/ • https://tanzu.vmware.com/developer • https://tanzu.tv • https://kubernetes.io/community/ - Slack, Google Groups, meetups • Free Training: • https://kube.academy/ • https://kubernetes.io/docs/tutorials/ • https://labs.play-with-k8s.com/
32. tiffanyfayj Special thanks to: Jérôme Petazzoni @jpetazzo THANK YOU!