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Cloud computing

Type of internet based computing that provides shared computer processing resources and data.

  • "bare metal" server with a virtualization layer on top of it
  • IaaS: infrastructure as a service (e.g. OpenStack)
  • PaaS: platform as a service
  • SaaS: software as a service

cloud services

(source: What is IaaS?)

Table of contents

OpenStack

  • gives components to set up cloud infrastructure, provides set of tools and services
  • backed up by big IT companies

OpenStack architecture

(source: What Is OpenStack | OpenStack Tutorial For Beginners | OpenStack Training | Edureka)

  • Keystone: authentication service (users and privilages)
  • Glance: launches instances from the images (e.g. Gentoo, Debian, CentOS)
  • Nova: computing domain
  • Neutron: networking service, responsible for communication between services
  • Swift: object storage component
  • Cinder: block storage component
  • Horizon: dashboard
  • Ceilometer: part of telemetric project
  • Heat: part of orchestration program.

The mission of the OpenStack Orchestration program is to create a human- and machine-accessible service for managing the entire lifecycle of infrastructure and applications within OpenStack clouds.

VM

(source: Virtual Machine)

Virtual machine (VM) is an emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized hardware, software, or a combination.

Some virtual machines, such as QEMU, are designed to also emulate different architectures and allow execution of software applications and operating systems written for another CPU or architecture.

Operating-system-level virtualization allows the resources of a computer to be partitioned via the kernel's support for multiple isolated user space instances

vm

img source

VM emulates hardware and kernel (see picture on the right) - this can have a negative impact on a performance.

Cgroups and namespaces

(source: difference between cgroups and namespaces)

  • Cgroups = limits how much you can use
  • namespaces = limits what you can see (and therefore use)
  • cgroup: Control Groups provide a mechanism for aggregating/partitioning sets of tasks, and all their future children, into hierarchical groups with specialized behaviour.
  • namespace: wraps a global system resource in an abstraction that makes it appear to the processes within the namespace that they have their own isolated instance of the global resource.

LXC

LXC

(source: LXC)

LXC (Linux Containers) is an operating-system-level virtualization method for running multiple isolated Linux systems (containers) on a control host using a single Linux kernel.

The Linux kernel provides the cgroups functionality that allows limitation and prioritization of resources (CPU, memory, block I/O, network, etc.) without the need for starting any virtual machines

LXC combines the kernel's cgroups and support for isolated namespaces to provide an isolated environment for applications.

Docker

Docker

  • creates the containers with the defined versions of software (e.g. Apache HTTP server)
  • unifies environments (build, test) across machines

Kubernetes

Kubernetes

A platform for working with containers:

  • deployment
  • scaling
  • monitoring

Problem

Instead of 3 servers you have 40 servers. How do you decide what containers go where

Solution

Use kubernetes to do it for you.

SaltStack

SaltStack automates repeated system administrative and code deployment tasks, eliminating manual processes in a way that can reduce errors that occur when IT organizations configure systems.

DriveTrain

Meanwhile check out:

See also