VDI, Containers, and Microservices

• VMs running in a data center instead of dedicated desktops/laptops

• Thin clients (minimal computers) for remote connections to the VMs.

• Management heaven

• Single point of failure

• SOA – Service Oriented Architecture

  • Then: monolithic (all in one) apps

  • Now: Virtualized app components designed around business requirements

  • Inputs and outputs

  • Sub services

  • No external state

  • Independent upgrades

  • Code independent

  • Easier interoperability

  • Communication mesh

• Containers – Isolated environments designed to run a set of applications

  • Docker

  • Flexible and fast

  • Development: create and destroy test environments

  • Packaging and distributing apps

  • Infrastructure as Code

  • Less secure out of the box than VMs

• Microservices

  • Split larger, monolithic functionality into individual microservices.

  • Replace, upgrade components individually

  • Brings the SOA approach to software development (agile)

  • No such thing as sub-microservice

  • Unix philosophy: each piece of software should do one thing and do it well.

  • Containers: #1 solution for a pure microservices based architecture

• SOAP

  • Microservices (and soa-based solutions) must communicate with each other

  • Historically, this was ensured by SOAP – Simple Object Access Protocol

  • SOAP manages sending and receiving data in web apps using XML

  • Security features: auth, encryptions, async, errors

  • Risks:

    • Proving

    • Coercive parsing

    • External references

    • Malware

    • SQL injection

• REST APIs

  • Used for interaction with services in a programmatic way

  • Machine to machine communication

  • SOAP (XML) vs REST APIs (HTTP)

  • APIs increase attack surface

  • API keys

  • REST (Representaiton State Transfer)

  • Principles:

    • Uniformity

    • Decoupling

    • Statelessness

    • Cacheabiltiy