Created: 2023-03-2620:03

What Problem Are We Hoping To Solve?

Originally when you wanted to run any OS as a server you had to have dedicated hardware to run that server. Eventually, Hypervisors came along and allowed for the use of multiple virtual machines on one set of given hardware. This allowed for one set of hardware to be utilized by a couple different operating systems.

The issue with this however is that this setup was really heavy and took a lot of time to boot up, and in comes docker.

virtual machine stack (top-down):

• virtual machines
• hypervisor (VMware)
• hardware

docker stack (top-down)

• containers
• docker-engine
• host OS (ubuntu)
• hardware

What are containers?

• fast
• lightweight
• microcomputers with their own:
  • OS
  • CPU
  • Mem
  • Network
• Isolated

Basic Docker Commands

get a docker image

• docker pull <image_name>

run docker container

• docker run -d -t --name <container_name> <image>
  • -d run the container in the background
  • -t allocate pseudo-TTY

interact with container

• docker exec -it <container_name> bash
• -i interactive
• -t pseudo-tty

Running Applications In Containers

• first, get an image of the container with the application in it.
  • Network Chuck uses: thenetworkchuck/nccoffee:frenchpress
  • docker pull thenetworkchuck/nccoffee:frenchpress
• then you want to run the containerized application
  • docker run -t -d -p 80:80 --name nccoffee thenetworkchuck/nccoffee:frenchpress
  • -t pseudo-tty
  • -d run in background
  • -p 80:80 map port 80 on our host to port 80 on the container
  • --name name the container

Why Docker Containers

• It is super fast!
  • all containers use the same kernel
  • the kernel is already running on the host os
• lightweight
  • only need one kernel
  • no hypervisor (heavy)
• Containerized applications will work anywhere
• microservices
  • segmenting portions of application
  • UI in one container
  • db in another container
  • etc

References:

1. https://www.youtube.com/watch?v=eGz9DS-aIeY