Kubernetes - Changing the way we build platforms

Presented at docker meetup in Melbourne 23/09/2015

Transcript

1. Kubernetes
   Changing the way we build platforms
   

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2. Who is this guy?
   @wolfeidau on twitter
   github.com/wolfeidau
   www.wolfe.id.au
   DevOps @ http://www.versent.com.au/
   

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3. Greek for “Helmsman”; also the root of the word
   “Governor”
   

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4. Kubernetes?
   • Inspired by an internal project at Google, called Borg
   • Contributors from Google, Mesos and more
   • 1.0 release a month or so ago
   

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5. Containers
   • Unix processes not lightweight Virtual Machines
   • Application + Dependencies = image
   • Runtime environment (cgroups, namespaces, environment
   variables)
   

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6. • Build applications in a dedicated build container or CI
   • Ship build artifacts, not build environments
   • Rails app container with build tools ~900MB
   • Rails app container without build tools ~300MB
   • Go service without build tools ~15MB
   • Cattle not Pets!
   Containers
   

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7. • Container management, scheduling, and service
   discovery.
   • API driven application management
   • Agents monitor endpoints for state changes (real-time)
   • Controllers enforce desired state
   • Resources (nodes, applications, services)
   Kubernetes
   

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8. Kubernetes
   • High level concepts
   • node
   • pod
   • scheduler
   • replication
   • service
   

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9. Node
   • Runs containers and proxies service requests.
   • docker
   • kubelet
   • proxy
   

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10. Pod
    • Represents a logical
    application.
    • One or more containers
    • Shared namespaces
    

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11. Scheduler
    • Schedules pods to run on nodes.
    • Global scheduler for long running jobs
    • Best fit chosen based on pod requirements
    • Pluggable
    

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12. Replication Controller
    • Manages a replicated set of pods.
    • Creates pods from a template
    • Ensures desired number of pods are running
    • Online resizing
    

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13. Replication Controller
    • Manages a replicated set of pods.
    • Creates pods from a template
    • Ensures desired number of pods are running
    • Online resizing
    

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14. Service
    • Service discovery for pods.
    • Proxy runs on each node
    • Virtual IP per service (avoid port collisions)
    • Basic round-robin algorithm
    • Dynamic backends based on label queries
    

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15. Example Pod
    apiVersion: v1
    kind: Pod
    metadata:
    labels:
    db: rethinkdb
    role: admin
    name: rethinkdb-admin
    spec:
    containers:
    - image: gcr.io/google_containers/rethinkdb:1.16.0_1
    name: rethinkdb
    env:
    - name: POD_NAMESPACE
    valueFrom:
    fieldRef:
    fieldPath: metadata.namespace
    ports:
    - containerPort: 8080
    name: admin-port
    volumeMounts:
    - mountPath: /data/rethinkdb_data
    name: rethinkdb-storage
    volumes:
    - name: rethinkdb-storage
    emptyDir: {}
    

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16. Example Service
    apiVersion: v1
    kind: Service
    metadata:
    labels:
    db: rethinkdb
    name: rethinkdb-admin
    spec:
    ports:
    - port: 8080
    targetPort: 8080
    type: LoadBalancer
    selector:
    db: rethinkdb
    role: admin
    

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17. Deployment
    • Continuous Integration / Deployment
    • Jenkins
    • Buildkite
    • Bamboo
    

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18. Transparency
    • Logging
    • ELK (Elastic Search, Logstash, Kibana)
    • Metrics
    • InfluxDB and Grafana
    • Tracing
    • Twitter Zipkin
    

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19. Resilience
    • Continuous Failure Testing
    • Chaos Monkey
    • Load Testing
    • Gattling
    • boom
    

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20. Cloud Providers
    • Kubernetes Supports
    • Google Cloud Compute and Container
    • AWS, being used by Samsung and Others
    • Openstack
    • Azure
    

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21. Questions?
    

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22. Links
    • Kubernetes Site
    • AWS Setup
    • CoreOS Kubernetes Vagrant
    • Kubernetes Rails Deployment
    • http://fabric8.io/
    

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