Raleigh NC Docker Meetup presentation from October 21, 2015. Doing development and test for an application on your laptop or a single server is an effective and quick way to ensure functionality, but can be limiting for larger applications. When the application is ready to deploy into production using containers, you’re going to want to use more than one server to increase resources and provide distributed availability. There are a large number of orchestration platforms for Docker which allow you to define an application consisting of one or more containers, and then coordinate deploying the application across small and large farms of servers. In this session we will concentrate on the three most popular orchestration platforms: Mesos, Kubernetes, and Docker Swarm. We will learn how each of them defines an application, some of their strengths, some weaknesses, and why you might choose one over another.

1. Docker Orchestrators
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2. Docker Orchestrators
1) Orchestrating Containerized Applications
2) The Orchestration Ecosystem
 Swarm
 Kubernetes
 Mesos
3) Deploying an Application
4) Advanced Topics
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3. Orchestrating Containerized Applications
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4. Applications Are Hard
 Monolithic applications
 Hard to update - single massive code
base
 Single dimension of scalability
 Waterfall development practices
 Static, linear phases
 Requirements
 Analysis
 Design
 Code
 Test
 Deploy
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Tomcat
Database
Apache
Image Service
Search Service
UI Service
WAR

5. Simplify the Problem
 Microservices
 Each component is independently
developed and scaled
 Everything is a platform
 DevOps
 Continuous Integration – Finding and
fixing bugs faster
 Continuous Deployment – Releasing
faster
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Load Balancer Tier
App Tier
Database Tier
UI Service Search Service
Image
Service

6. The Orchestrator Ecosystem
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7.  Multiple Swarm hosts behave like a
single Docker host
 Still uses Docker CLI
 Uses standard Docker API
 Execute containers against the cluster
just like a single host
 Application definitions using Compose
 Not fully functional yet, network is incomplete
Docker Swarm
Image: http://www.slideshare.net/rajdeep/docker-swarm-introduction
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8.  Based on Google Borg
 Abstracts applications into
pods and services
 Schedules containers
against cluster nodes
using kubelets
Kubernetes
Image: https://github.com/kubernetes/kubernetes/blob/master/docs/design/architecture.md
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9.  Mesos
 Abstraction of resources: CPU, RAM, etc.
 Generic execution of any task against resources
 Frameworks define application types
 Marathon, Chronos, Hadoop, Aurora, Jenkins,
Cassandra
 Marathon
 Framework for scheduling applications onto
Mesos providing private PaaS
 Meta-framework, e.g. can start Chronos jobs
Mesos + Marathon
Image: https://mesosphere.github.io/marathon/
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10. Important Services
 Scheduling
 Swarm: Spread, BinPack, random + filters
 Kubernetes: FitPredicate, PriorityFunction
 Marathon: Resource offers + constraints, Cluster, Group_by, Like, Unlike
 Service discovery
 Internal DNS which registers applications
 Networking
 Overlay networks: Flannel, libnetwork (SocketPlane), Weave
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11. Deploying an Application
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12. Our Sample Application
 Multi-tier web application
 Database
 Web Application
 Not included
 Load balancer(s)
 Distributed database
 Horizontally scalable microservices
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13.  Use standard docker CLI
 Define the application using Compose
 Simple, well known syntax
 Scalability of components at the
command line:
 docker-compose scale phpmyadmin:1 db:2
Docker Swarm
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14. Kubernetes
 Pods
 Group(s) of containers
 Replication Controllers
 Container lifecycle management
 Services
 Endpoint for one or more pods or
replication controllers
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Pod
Replication
Controller
App:10.0.0.1
OR

15. Kubernetes
 Pods
 Group(s) of containers
 Replication Controllers
 Container lifecycle management
 Services
 Endpoint for one or more pods or
replication controllers
© 2015 NetApp, Inc. All rights reserved.15

16. Kubernetes
 Pods
 Group(s) of containers
 Replication Controllers
 Container lifecycle management
 Services
 Endpoint for one or more pods or
replication controllers
© 2015 NetApp, Inc. All rights reserved.16

17. Kubernetes
 Pods
 Group(s) of containers
 Replication Controllers
 Container lifecycle management
 Services
 Endpoint for one or more pods or
replication controllers
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18.  Application group to define multiple
components
 Dependency tracking
 Scalability
 Constraints
 App components are standard Marathon
definitions
Mesos + Marathon
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19.  Application Group definition
 Application definition
 Container definition
Mesos + Marathon
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20.  Application Group definition
 Application definition
 Container definition
Mesos + Marathon
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21.  Application Group definition
 Application definition
 Container definition
Mesos + Marathon
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22. Advanced Topics
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23. Persistent Storage
 Swarm
 volumes, volumes_from, volume_driver
 Kubernetes
 Persistent Volume Request mechanism
 Predefined, pre-allocated units of storage
 Mesos + Marathon
 Persistent Volumes – Partially implemented by Mesos,
not implemented by Marathon
 Docker pass-through volumes
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Swarm Volume Definition
Kubernetes Volume DefinitionMarathon Volume Definition

24. Additional Orchestrator Considerations
 Authentication and authorization
 Distributed configuration management
 etcd, zookeeper, etc.
 Secrets management
 Application HA / healing
 Application scaling
 Logging
 Monitoring
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25. Summary
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26. Key Takeaways
 Choose the orchestrator that best fits your needs
 Be conscious of complexity
 Development and Operations must get along!
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27. Other Orchestrators
 Tutum
 Mesosphere DCOS
 Rancher
 CoreOS
 Nomad
 OpenStack Magnum (Kubernetes/Swarm)
 StackEngine
 Decking
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28. Additional Resources
 Swarm
 Documentation: https://docs.docker.com/swarm/
 Kubernetes
 Application Management Documentation - http://bit.ly/1M898gS
 Mesos + Marathon
 Documentation: https://mesosphere.github.io/marathon/docs/
 Sample Code
 https://github.com/Practical-Admin/meetup/
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29. Questions?
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30. Thank you
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