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KUBERNETES

BJÖRN BESKOW

2016-01-27

Many small, moving parts

BACKGROUND

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Software, Hardware & Networks

BACKGROUND

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Failures are inevitable

BACKGROUND

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Ephemeral

BACKGROUND

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11 Source: https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43438.pdf

Treat all hardware nodes as one giant logical

machine

GOALS

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Focus on your "applications"

GOALS

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Manage your applications through "Wishful Thinking": Declare how it ought to be

GOALS

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16 Source: http://kubernetes.io/

DEMO SETUP

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DEMO SETUP

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DEMO SETUP

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Source: https://github.com/rimusz/coreos-osx-kubernetes-cluster

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Kubectl CLI CORE CONCEPTS

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• Node CORE CONCEPTS

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• Node • Container

CORE CONCEPTS

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• Node • Container • Pod

CORE CONCEPTS

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apiVersion: v1 kind: Pod metadata: name: quotes spec: containers: - name: quotes image: docker:5000/quotes:1 ports: - containerPort: 9090 hostPort: 9090

QUOTES-POD.YAML

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• Node • Container • Pod • Replication Controller

CORE CONCEPTS

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replicas: 2

Upcoming feature: auto-scaling based on load: see https://github.com/kubernetes/kubernetes/blob/master/docs/design/horizontal-pod-autoscaler.md

apiVersion: v1 kind: ReplicationController metadata: name: quotes spec: replicas: 2 ... template: spec: containers: - name: quotes image: docker:5000/quotes:1

QUOTES-CONTROLLER.YAML

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replicas: 2

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• Node • Container • Pod • Replication Controller • Labels

CORE CONCEPTS

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app:quotes

app:quotes

• Node • Container • Pod • Replication Controller • Labels

CORE CONCEPTS

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app:quotes version: 1 tier: backend

app:quotes version: 2 tier: backend

app:portal version: 1 tier: frontend

app:portal version: 2 tier: frontend

• Node • Container • Pod • Replication Controller • Labels

CORE CONCEPTS

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app:quotes version:1 tier:backend

app:quotes version:2 tier:backend

app:portal version:1 tier:frontend

app:portal version:2 tier:frontend

selector: app:quotes

• Node • Container • Pod • Replication Controller • Labels

CORE CONCEPTS

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app:quotes version:1 tier:backend

app:quotes version:2 tier:backend

app:portal version:1 tier:frontend

app:portal version:2 tier:frontend

selector: version:1

• Node • Container • Pod • Replication Controller • Labels

CORE CONCEPTS

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app:quotes version:1 tier:backend

app:quotes version:2 tier:backend

app:portal version:1 tier:frontend

app:portal version:2 tier:frontend

selector: app:quotes version:1

• Node • Container • Pod • Replication Controller • Labels

CORE CONCEPTS

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app:quotes

app:quotes

replicas: 2 selector: app:quotes

apiVersion: v1 kind: ReplicationController metadata: name: quotes labels: app: quotes spec: replicas: 2 selector: app: quotes version: 1 template: ...

QUOTES-CONTROLLER.YAML

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replicas: 2 selector: app:quotes version:1

... template: metadata: labels: app: quotes version: 1 spec: containers: - name: quotes image: docker:5000/quotes:1 ports: - containerPort: 9090

QUOTES-CONTROLLER.YAML

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app:quotes version:1

app:quotes version:1

• Node • Container • Pod • Replication Controller • Label • Liveness

CORE CONCEPTS

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... livenessProbe: httpGet: path: /health port: 9090 initialDelaySeconds: 10 timeoutSeconds: 1

QUOTES-CONTROLLER.YAML

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• Node • Container • Pod • Replication Controller • Label • Liveness •  Service

CORE CONCEPTS

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app:quotes

app:quotes

app:portal

• Node • Container • Pod • Replication Controller • Label • Liveness •  Service

CORE CONCEPTS

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app:quotes

app:quotes

app:portal

name:quotes-service selector: app:quotes

apiVersion: v1 kind: Service metadata: name: quotes-service labels: app: quotes tier: frontend spec: ports: - port: 8080 targetPort: 8080 selector: app: quotes

QUOTES-SERVICE.YAML

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app:quotes

app:quotes

name:quotes-service selector: app:quotes

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ADVANCED CONCEPTS: ROLLING UPGRADE

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app:quotes version:1

app:portal

name:quotes-service selector: app:quotes

app:quotes version:1

ADVANCED CONCEPTS: ROLLING UPGRADE

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app:quotes version:2

app:portal app:quotes version:2

name:quotes-service selector: app:quotes

ADVANCED CONCEPTS: ROLLING UPGRADE

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app:quotes version:2

app:portal app:quotes version:2

name:quotes-service selector: app:quotes app:quotes

version:1

app:quotes version:1

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•  Container Orchestration software like Kubernetes provides highly valuable capabilities for Microservice architectures: - Decoupling logical components from each other and from the

infrastructure •  Kubernetes is just one of many alternatives (Mesos, Helios, Docker

Swarm, …), but its Google background makes it one of the most interesting. Stay tuned!

CONCLUSIONS

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TIME FOR QUESTIONS?