From Engines to Orchestrators

Lee Calcote
Sept 30th, 2016

Lee Calcote

clouds, containers, infrastructure, applications

 and their management

Show of Hands

Types of Containers

System Containers

  • Like a VM
  • Full OS image
  • Multiple processes

Application Containers

  • Single process
  • Use namespaces to deal with resource isolation for a single process.

  • Use cgroups to manage resources for a group of processes.

Similarities:

  • rkt
  • docker
  • runC
  • kurma

---

  • containerd
  • systemd-nspawn
  • OpenVZ
  • Solaris Zones
  • BSD jails
  • Linux-VServer
  • AIX WPARs
  • LXC

----

  • LXD
  • CGManager
  • machinectl

----

  • qemu-kvm, lkvm

System Container Engines

Application Container Engines

Container Specifications

Implemented by -

  • rkt is the canonical implementation
  • Kurma leverages runC 
  • Jetpack is an implementation of for FreeBSD using jails and ZFS

Implemented by -

  • runC is the reference implementation
  • runV is a hypervisor-based runtime
  • cc-oci-runtime launches an Intel VT-x secured Clear Containers 2.0 hypervisor

 

 

  • image-spec

    • a software shipping container image format spec with security and naming as components

  • image-tools

    • tooling for the image 

Get Started with your Engines

and get your engines started

Popular Engine
process models

  • rkt executes as CLI; no daemon

  • Can run Docker Images and also App Container Images (ACIs)

  • Security has been a focal concern 

  • uses HTTPS to locate and download remote ACIs and their attached signatures

  • Docker Engine runs a daemon

rkt

systemd

$ rkt run postgres

application

systemd

$ docker run postgres

application

Docker Engine

containerd

runC

Definition:

[ awr -k uh -streyt -or]

[k uh n- tey-ner]

Core
Capabilities

  • Cluster Management

    • Host Discovery

    • Host Health Monitoring

  • Scheduling

  • Orchestrator Updates and Host Maintenance

  • Service Discovery

  • Networking and Load-Balancing

Additional
Key Capabilities

  • Application Health Monitoring

  • Application Deployments

  • Application Performance Monitoring

One size does not fit all.

A strict apples-to-apples comparison is inappropriate and not the objective, hence  characterizing  and  contrasting.

Kubernetes

Genesis & Purpose

  • an opinionated framework for building distributed systems

    • or as its tagline states "an open source system for automating deployment, scaling, and operations of applications."

  • Written in Golang, Kubernetes is lightweight, modular and extensible

  • considered a third generation container orchestrator led by Google, Red Hat and others.

    • bakes in load-balancing, scale, volumes, deployments, secret management and cross-cluster federated services among other features.

  • Declaratively, opinionated with many key features included

 

Docker Swarm

Genesis & Purpose

  • Swarm is simple and easy to setup.
     

  • Swarm is responsible for the clustering and scheduling aspects of orchestration.  
     

  • Originally an imperative system, now declarative
     

  • Swarm’s architecture is not complex as those of Kubernetes and Mesos
     

  • Written in Golang, Swarm is lightweight, modular and extensible

Mesos

+

Marathon

Genesis & Purpose

  • Mesos is a distributed systems kernel

    • stitches together many different machines into a logical computer

  • Mesos has been around the longest (launched in 2009)

    • and is arguably the most stable, with highest (proven) scale currently

  • Mesos is written in C++

    • with Java, Python and C++ APIs

  • Marathon as a Framework

    • Marathon is one of a number of frameworks (Chronos and Aurora other examples) that may be run on top of Mesos

    • Frameworks have a scheduler and executor. Schedulers get resource offers. Executors run tasks.

    • Marathon is written in Scala

Summary

A high-level perspective of the container orchestrator spectrum

Lee Calcote

Thank you. Questions?

clouds, containers, infrastructure,

applications  and their management

ContainerizeThis 2016: From Engines to Orchestrators

By Lee Calcote

ContainerizeThis 2016: From Engines to Orchestrators

An introduction to container engines (runtimes) and an understanding of when container orchestrators enter and what role they play. We’ll look at what makes each alike, yet unique.

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