Set Sail with Kubernetes

Intro to Kubernetes deck presented to the Alamo Tech Collective in San Antonio, June 2025

Transcript

1. Set Sail with Kubernetes
2. $kubectl auth whoami Hart Hoover I work at Cisco, by way of Isovalent, makers of Cilium and Tetragon Formerly CoreOS, Heptio/VMware, Rackspace, Kong #GirlDad who loves tacos and coffee, perhaps too much https://harthoover.com
3. Agenda • WTF is Kubernetes? • Pods • More Pods • Config Data • Gateways • I want to run it • Services
4. History Lesson dotCloud joins YCombinator 2010 dotCloud ➡ Docker, Inc in 2013 EC2 just started supporting custom kernels Linux 3.0 was not out yet Terraform did not exist Go 1.0 had not been released “Config Management” was mostly Bash OpsCode wasn’t Chef, Inc. Netflix Engineering was blogging about building AMIs
5. History Lesson 2013
6. History Lesson Google open-sourced Kubernetes on June 6, 2014 Docker Swarm was released Oct 2014 CNCF was founded in 2015, Kubernetes was its first project
9. WTF is Kubernetes?
10. WTF is Kubernetes? Kubernetes is a Greek word that means “helmsman” or “pilot” Kubernetes is an open source container orchestration engine for automating deployment, scaling, and management of containerized applications.
11. WTF does Kubernetes Do? Abstracts underlying hardware of nodes and provides a uniform interface for container (and now VM!) workloads to be both deployed and consume the shared pool of resources.
12. WTF does Kubernetes Do? Kubernetes… Autoscales workloads Manages Deployments Runs Stateful and Stateless Apps Has built-in Service Discovery Supports third party applications
13. Constantly resolves state between what is actual and what is desired WTF does Kubernetes Do?
14. WTF does Kubernetes Look Like? etcd (Data Store) API Server Scheduler Controller Manager You (kubectl) Node1 Network Plugin Kubelet Container Runtime OS Node2 Network Plugin Kubelet Container Runtime OS NodeN Network Plugin Kubelet Container Runtime OS Controllers Nodes Kube-Proxy Kube-Proxy Kube-Proxy
15. WTF does Kubernetes Look Like? etcd (Data Store) API Server Scheduler Controller Manager Controllers
16. WTF does Kubernetes Look Like? Node1 Network Plugin Kubelet Container Runtime OS Node2 Network Plugin Kubelet Container Runtime OS NodeN Network Plugin Kubelet Container Runtime OS Nodes Kube-Proxy Kube-Proxy Kube-Proxy
17. WTF does Kubernetes Look Like? Node1 Kubelet Node2 Kubelet NodeN Kubelet Nodes Kube-Proxy Kube-Proxy Kube-Proxy
18. WTF does Kubernetes Look Like? etcd (Data Store) API Server Scheduler Controller Manager You (kubectl) Node1 Network Plugin Kubelet Container Runtime OS Node2 Network Plugin Kubelet Container Runtime OS NodeN Network Plugin Kubelet Container Runtime OS Controllers Nodes Kube-Proxy Kube-Proxy Kube-Proxy
19. Pods
21. Pods apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
22. Pod Templates apiVersion: batch/v1 kind: Job metadata: name: hello spec: template: # This is the pod template spec: containers: - name: hello image: busybox:1.28 command: ['sh', '-c', 'echo "Hello, Kubernetes!" && sleep 3600'] restartPolicy: OnFailure # The pod template ends here
23. Sidecars Main container initContainer Main container proxy Main container debug
24. More Pods
25. Deployments and ReplicaSets apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment labels: app: nginx spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
26. Deployments and ReplicaSets apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment labels: app: nginx spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
27. Deployments and ReplicaSets apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment labels: app: nginx spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
28. Deployments and ReplicaSets apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment labels: app: nginx spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
29. Deployments and ReplicaSets replicas: 3 image: image:v1
30. Deployments and ReplicaSets replicas: 3 image: image:v1
31. Deployments and ReplicaSets image:v1 replicas: 3 image: image:v1
32. Deployments and ReplicaSets image:v1 replicas: 3 image: image:v2
33. Deployments and ReplicaSets image:v1 image:v2 replicas: 3 image: image:v2
34. Deployments and ReplicaSets replicas: 3 image: image:v2 image:v2
35. DaemonSets apiVersion: apps/v1 kind: DaemonSet metadata: name: fluentd spec: selector: matchLabels: name: fluentd template: metadata: labels: name: fluentd spec: containers: - name: fluentd-elasticsearch image: quay.io/fluentd_elasticsearch/fluentd:latest
36. DaemonSets apiVersion: apps/v1 kind: DaemonSet metadata: name: fluentd spec: selector: matchLabels: name: fluentd template: metadata: labels: name: fluentd spec: containers: - name: fluentd-elasticsearch image: quay.io/fluentd_elasticsearch/fluentd:latest
37. DaemonSets apiVersion: apps/v1 kind: DaemonSet metadata: name: fluentd spec: selector: matchLabels: name: fluentd template: metadata: labels: name: fluentd spec: containers: - name: fluentd-elasticsearch image: quay.io/fluentd_elasticsearch/fluentd:latest
38. Config Data
39. ConfigMaps and Secrets apiVersion: v1 kind: ConfigMap metadata: name: game-demo data: player_initial_lives: "3" ui_properties_file_name: "user-interface.properties"
40. ConfigMaps and Secrets apiVersion: v1 kind: Secret metadata: name: dotfile-secret data: .secret-file: dmFsdWUtMg0KDQo=
41. Using a ConfigMap apiVersion: v1 kind: Pod metadata: name: configmap-demo-pod spec: containers: - name: demo image: alpine command: ["sleep", "3600"] env: - name: PLAYER_INITIAL_LIVES valueFrom: configMapKeyRef: name: game-demo key: player_initial_lives - name: UI_PROPERTIES_FILE_NAME valueFrom: configMapKeyRef: name: game-demo key: ui_properties_file_name
42. Services
43. Pods apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
44. Services apiVersion: v1 kind: Service metadata: name: my-service spec: selector: app.kubernetes.io/name: nginx ports: - protocol: TCP port: 80 targetPort: 80
45. Services apiVersion: v1 kind: Service metadata: name: my-service spec: selector: app.kubernetes.io/name: nginx ports: - protocol: TCP port: 80 targetPort: 80
46. Services apiVersion: v1 kind: Service metadata: name: my-service spec: selector: app.kubernetes.io/name: nginx ports: - protocol: TCP port: 80 targetPort: 80
47. Services apiVersion: v1 kind: Service metadata: name: my-service spec: selector: app.kubernetes.io/name: nginx ports: - protocol: TCP port: 80 targetPort: 80
48. Main Types of Services • ClusterIP (default) • NodePort • LoadBalancer
49. Blue/Green Deployments labels: app: myapp env: blue selector: app: myapp env: blue v1
50. Blue/Green Deployments labels: app: myapp env: blue labels: app: myapp env: green selector: app: myapp env: blue v1 v2
51. Blue/Green Deployments labels: app: myapp env: blue labels: app: myapp env: green selector: app: myapp env: green v1 v2
52. Blue/Green Deployments labels: app: myapp env: blue labels: app: myapp env: green selector: app: myapp env: green v3 v2
53. Canary labels: app: myapp selector: app: myapp v1 Deployments
54. Canary labels: app: myapp labels: app: myapp type: canary selector: app: myapp v1 v2 Deployments
55. Canary labels: app: myapp labels: app: myapp type: canary selector: app: myapp v2 v2 Deployments
56. Canary labels: app: myapp selector: app: myapp v2 Deployments
57. Gateways
58. An API and standardization for traffic management and routing in a Kubernetes cluster Gateway API
59. Client Gateway GatewayClass Cluster HTTPRoute HTTPRoute domain.com /products /reviews What kind?
60. apiVersion: gateway.networking.k8s.io/v1 kind: Gateway metadata: name: prod-web spec: gatewayClassName: cilium listeners: - protocol: HTTP port: 80 name: prod-web-gw allowedRoutes: namespaces: from: Same Simple Gateway API Objects apiVersion: gateway.networking.k8s.io/v1 kind: HTTPRoute metadata: name: route spec: parentRefs: - name: prod-web rules: - backendRefs: - name: foo-svc port: 8080
61. https://gateway-api.sigs.k8s.io/
62. I want to run it
63. • https://docs.docker.com/desktop/ 💰 • https://podman-desktop.io/ • https://minikube.sigs.k8s.io/ • https://kind.sigs.k8s.io/ • Cloud Options: EKS, GKE, AKS, etc 💰 I want to run it
64. https://github.com/kelseyhightower/kubernetes-the-hard-way I want to learn the internals
65. https://github.com/kubernetes/community I want to contribute
66. DEMO
68. Thank you