session-55.txt

mongodb
redis
mysql
rabbitmq

logs
metrics

1. dont keep stateful apps in containers
2. if we want we can keep not end user stateful apps

shell vs ansible

with in docker host we are using bridge network


autoscaling, networking, storing secrets, managing volumes is difficult in docker swarm, heavy applications are not suitable

we need kubernetes

workstation
===========
1. Install docker -> build the images, push the images to ECR repo hub
2. eksctl -> create, update and delete the eks cluster
3. kubectl -> connect with eks cluster
4. aws cli (aws configure) -> to provide authentication while creating cluster, connecting to cluster


sudo growpart /dev/nvme0n1 4
sudo lvextend -L +30G /dev/RootVG/varVol
sudo xfs_growfs /var

sudo dnf -y install dnf-plugins-core
sudo dnf config-manager --add-repo https://download.docker.com/linux/rhel/docker-ce.repo
sudo dnf install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin -y
sudo systemctl start docker
sudo systemctl enable docker
sudo usermod -aG docker ec2-user

# for ARM systems, set ARCH to: `arm64`, `armv6` or `armv7`
ARCH=amd64
PLATFORM=$(uname -s)_$ARCH

curl -sLO "https://github.com/eksctl-io/eksctl/releases/latest/download/eksctl_$PLATFORM.tar.gz"

# (Optional) Verify checksum
curl -sL "https://github.com/eksctl-io/eksctl/releases/latest/download/eksctl_checksums.txt" | grep $PLATFORM | sha256sum --check

tar -xzf eksctl_$PLATFORM.tar.gz -C /tmp && rm eksctl_$PLATFORM.tar.gz

sudo install -m 0755 /tmp/eksctl /usr/local/bin && rm /tmp/eksctl


curl -O https://s3.us-west-2.amazonaws.com/amazon-eks/1.35.2/2026-02-27/bin/linux/amd64/kubectl
chmod +x ./kubectl
mkdir -p $HOME/bin && cp ./kubectl $HOME/bin/kubectl && export PATH=$HOME/bin:$PATH

spot instances
===============
1TB RAM, 200TB HD

40GB RAM, 80TB HD -> not in use
70-80% discount they give us if we use this..
AWS will take out these spot instances with 2 min notice...

eksctl create cluster --config-file=eks.yaml

DOCKER_BUILDKIT=0 docker build -t user:1.0.0 --rm=false --no-cache .

FROM node:20 -> create container from it
login to that intermediate container

run this instruction
WORKDIR /app

create image out of this container -> image-abcfd1234

create container from abcd1234 -> container id is container-xyz1234

xyz1234 -> run next instruction COPY package.json . -> image-dfd5346

create container from image-dfd5346 called container-fadh1632

docker layers
=============
docker creates intermediate container for every instruction
it will run next following instruction inside this container -> create image out of it
then it creates another intermediate container from that image, run the next instruction -> create image out of it

so for every instruction new layers are created -> docker exports all these layers into hub while pushing the image
so for every instruction new layers are created -> docker exports all these layers into hub while pushing the image

we must keep frequently changing instructions at the bottom of Dockerfile to make the build process fast and storage