Kubernetes - Day - 01

Why Docker ?

• What Docker resolves ? --> Lets see , before that lets see some in-depth concepts.

CONTAINERS

• App
• Base OS what you need ( Mostly it will be linux flavour )
• Requirements ( packages )
• what to run.
• Even Python can be a base OS.

With these entire item we can make a package and we can build a image and deploy.

• With this image --> spawn into CONTAINER.
• Container is purely LINUX based.
• Sometimes it runs in windows , how ? WSL - Windows Subsystem Linux Layer.
• How this is working , in Linux , we have CGROUP , which allows the windows to run or support.
• இந்த Container technologyயை ஒரு service கொடுக்கிறது தான் --> Many tools are there , One such company is DOCKER , PODMAN.

In DOCKER --> Docker Engine is Open-Source. If you are planning to use Docker Desktop then you need to pay.
In Podman --> All are Open-Source.

COMMONDS

- docker pull ubuntu
- docker run -it ubuntu bash
- docker ps -a
- docker rm -f $(docker ps -aq)

Notes :

1. Bare Metal -- > Its like a simple laptop with OS. ஒரு OS அதுக்கப்புறம் Applicationக்கு தேவைப்படுற files அவ்வளவுதான் இருக்கும்.
2. Image is nothing but OS or the application itself , from image it will become CONTAINER.
3. Many Images are called Registery.
4. With 40mb we can spawn a OS- Ubuntu. See below.

TBD :

1. What is redis ?
2. Just learn docker engine installation.
3. What is CGROUGS ?

LEARN