Debug School: Palak Garg

Kubernetes

Palak Garg — Wed, 26 Apr 2023 09:50:25 +0000

What is Kubernetes?
Kubernetes is an open-source container Orchestrator. It is designed by google in 2015. It has Workload placement, infrastructure placement, and Desired state
Why Kubernetes
It has self-healing, automated rollbacks, auto Scaling and load balancing capability
Speed of deployment is fast
Enhance productivity
Improve security
Explained Kubernetes Architecture
It has Kubernete cluster which comprise of masters and nodes
Master Components
Kube-apiserver which acts as Control panel
Cluster store is powered by ectd
Kube -Controller manager it watches for changes
Kube -Scheduler – watces api server for pods
Worker Components
Kubelet is a main Kubernetes agent

Container engine
Kube-proxy
Workstation Components
Kubelet we use json or yaml
What is POD?
It is atomic unit which is responsible for running containers inside it

Docker Day2 Assignment

Palak Garg — Wed, 26 Apr 2023 08:20:20 +0000

*Executed some more Docker commands *
• cp
• diff
• rename
• port
• update
• wait
• logs
• events
• top
• inspect
*Docker commands for images *
• docker images
• docker pull
• docker info
• docker rmi
• docker inspect
• docker commit – m “message” – a”name” container id alias name

*How to design docker image *
docker run -itd ubuntu docker exec -it “containerid” /bin/bash
install java
apt-get update apt-get install openjdk-11-jdk -y apt-get install openjdk-11-jdk-headless -y
install apache
apt-get install apache2 -y
Install wget
apt-get install wget -y
Install war file
wget https://tomcat.apache.org/tomcat-7.0-doc/appdev/sample/sample.war chmod 755 sample.war
commit the image

docker commit -m"message" -a"Palak" containerid name docker images
Validate java and apache
docker exec containerid java docker exec containerid which apache2 docker exec containerid ls /opt/
Saving and loading tar file
After committing the docker image
Save the file
docker save -o image.tar name of image
you can stop the containers if u want
Load the file
docker load -i image.tar
Pushing the docker image to repository
Create an account in docker hub
Login to docker hub in putty
docker login
provide username and password
tag the image matching to repo name
docker tag image palakg1904/demo
Push the image to repo
docker push palakg1904/demo

Docker Day 1 Assignment

Palak Garg — Tue, 25 Apr 2023 04:45:24 +0000

What is Docker?
Docker is a container management tool or software platform that allows you to build, test and deploy applications quickly.

Why We need docker?
It reduces the cost
It saves time as it deploys code quickly
It improves software quality

What is Container?
A container is a standard unit of software that packages up code and all its dependencies, so the application runs quickly and reliably from one computing environment to another

How Container Works?
It is a runnable instance of an image. You can create, start, stop, move, or delete a container

How to install Docker?
Step 1 – Download and Run the script.
$ curl -fsSL get.docker.com -o get-docker.sh
$ sudo sh get-docker.sh
Step 2 – Enable Docker
$ sudo systemctl enable docker
Step 3 – Start Docker
$ sudo systemctl start docker
Step 4 – Verify that docker is installed correctly by running the hello-world image.
$ sudo docker run hello-world

What are the components docker?
Docker Engine
Docker Images
Registry
Containers

What is a container lifecycle commands?
Docker create “docker name”
Docker start “container id”
Docker restart “container id”
Docker pause “container id”
Docker unpause “container id”
Docker stop “container id”
Docker kill “container id”
Docker stats “container id”
Docker rm “container id”

What is docker pause/unpause?
Docker pause is used to pause the session which are not active currently to save CPU resources
Docker unpause command is used to unpause the session which is paused currently to resume the session

What is docker stop/kill?
Docker stop will end the session with Exit (0) code and it stops container gracefully
Docker Kill will terminate the session abruptly with Exit (137) code

How to get inside a container?
docker run -it -d ubuntu /bin/bash
docker run -itd ubuntu /bin/bash
docker exec 955a249cbf71 ls
docker exec 955a249cbf71 ps -eaf
docker exec -it 955a249cbf71 /bin/bash

How to access container from outside?
docker inspect 955a249cbf71
docker ps
curl http://172.17.0.9
ping "172.17.0.9"

What is the rule for container is running?
Attached to a terminal of PID1 of the container. PID changes