DevOps Classroom notes 31/Dec/2023

Docker contd

Monolith

• All the business logic is developed as one single application
• In the below example the whole of ecommerce is developed as single application
  
• All the code is developed as one large code base
• Advantages:
  • Convinient to build and deploy
• Disadvantages:
  • Smaller changes also require downtimes
  • All of the application should be in same programming language

Microservice

• Each Business component/functionality is created as indivudually runnable service
• Each service can be scaled and Each service can be individually update without impacting the other services
  
• Advantages:
  • deploying without downtimes
  • frequent updates
  • technology independent
• Disadvantanges
  • Complex and needs an external orchestration

Docker

• libContainer:
  • Earlier docker engine used to speak with linux kernel to create containers, so some updates to kernels used to impact container
  • docker has implemented libcontainer Refer Here which creates containers rather than depending on linux kernel
• Docker after success has started adding lots of features making it fat.
• Refer Here for oci

Install Docker

• Docker can create two types of containers
  • Linux Containers:
    • They run everywhere
  • Windows Containers
    • They run only on windows
• Create a ubuntu 22.04 Linux vm in any cloud of your choice
• ssh into it and install docker

curl -fsSL https://get.docker.com -o install-docker.sh
sh install-docker.sh

• After installation execute sudo docker info
  

Exercises

• Create a docker hub account Refer Here
• Install necessary softwares Refer Here
• Mac:
  • Install homebrew Refer Here
  • Git brew install git
  • Visual studio code brew install --cask visual-studio-code