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Python – user input

$ vim user_input.py
roll_num = int(input("Enter your roll no.:"))
message = "Hello user your roll number is " + str(roll_num)
print(message)
:x

or

$ vim user_input.py
roll_num = int(input("Enter your roll no.:"))
print("Hello user your roll number is " + str(roll_num))
:x 

$ python user_input.py


Python print statement

syntax:
print(object(s), sep=separator, end=end, file=file, flush=flush)

$ print("Hello, Python!")
$ print('Hello, World!')
$ print("Hello","Dhana")

$ vim print.py
x = ("python", "php", "c", "c++")
print(x)
:x
$ python print.py

Terraform code for AWS Postgresql RDS

create directory postgres and navigate
$ mkdir postgres && cd postgres
create main.tf file
$ vim main.tf

provider "aws" {
}
resource "aws_security_group" "rds_sg" {
name = "rds_sg"
ingress {
from_port = 5432
to_port = 5432
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
}

resource "aws_db_instance" "myinstance" {
engine = "postgres"
identifier = "myrdsinstance"
allocated_storage = 20
engine_version = "14"
instance_class = "db.t3.micro"
username = "myrdsuser"
password = "myrdspassword"
parameter_group_name = "default.postgres14"
vpc_security_group_ids = ["${aws_security_group.rds_sg.id}"]
skip_final_snapshot = true
publicly_accessible = true
}

output "rds_endpoint" {
value = "${aws_db_instance.myinstance.endpoint}"
}

save and exit
$ terraform init
$ terraform plan
$ terraform apply -auto-approve
Install postgres client in local machine
$ sudo apt install -y postgresql-client
To access AWS postgresql RDS instance
$ psql -h <end_point_URL> –p=5432 –username=myrdsuser –password –dbname=mydb
To destroy postgresql RDS instance
$ terraform destroy -auto-approve

Terraform code for AWS MySQL RDS

create directory mysql and navigate
$ mkdir mysql && cd mysql
create main.tf
$ vim main.tf

provider "aws" {
}
resource "aws_security_group" "rds_sg" {
name = "rds_sg"
ingress {
from_port = 3306
to_port = 3306
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
}

resource "aws_db_instance" "myinstance" {
engine = "mysql"
identifier = "myrdsinstance"
allocated_storage = 20
engine_version = "5.7"
instance_class = "db.t2.micro"
username = "myrdsuser"
password = "myrdspassword"
parameter_group_name = "default.mysql5.7"
vpc_security_group_ids = ["${aws_security_group.rds_sg.id}"]
skip_final_snapshot = true
publicly_accessible = true
}

output "rds_endpoint" {
value = "${aws_db_instance.myinstance.endpoint}"
}

save and exit
$ terraform init
$ terraform plan
$ terraform apply -auto-approve
install mysql client in local host
$ sudo apt install mysql-client
To access the mysql
$ mysql -h <end_point_URL> -P 3306 -u <username> -p
To destroy the mysql RDS instance
$ terraform destroy -auto-approve

code for s3 bucket creation and public access

provider "aws" {
region = "ap-south-1"
}

resource "aws_s3_bucket" "example" {
bucket = "example-my"
}

resource "aws_s3_bucket_ownership_controls" "ownership" {
bucket = aws_s3_bucket.example.id
rule {
object_ownership = "BucketOwnerPreferred"
}
}

resource "aws_s3_bucket_public_access_block" "pb" {
bucket = aws_s3_bucket.example.id

block_public_acls = false
block_public_policy = false
ignore_public_acls = false
restrict_public_buckets = false
}

resource "aws_s3_bucket_acl" "acl" {
depends_on = [aws_s3_bucket_ownership_controls.ownership]
bucket = aws_s3_bucket.example.id
acl = "private"
}

S3 bucket creation and object storage

create directory s3-demo and navigate
$ mkdir s3-demo && cd s3-demo
create a demo file sample.txt and contents
$ echo β€œthis is sample object to store in demo-bucket” > sample.txt
create main.tf file
$ vim main.tf

provider "aws" {
region = "ap-south-1"
}

resource "aws_s3_bucket" "example" {
bucket = "mydemo-bucket1"
}

resource "aws_s3_object" "object" {
bucket = aws_s3_bucket.example.bucket
key = "sample.txt"
source = "./sample.txt"
}

save and exit
$ terraform init
$ terraform plan
$ terraform apply -auto-approve

create S3 bucket using terraform

create directory s3 and navigate to the directory
$ mkdir s3 && cd s3
create main.tf file
$ vim main.tf

provider "aws" {
region = "ap-south-1"
}

resource "aws_s3_bucket" "my_bucket" {
bucket = "mydemo-bucket"
}

save and exit
$ terraform init
$ terraform plan
$ terraform apply -auto-approve
To destroy the bucket
$ terraform destroy -auto-approve

How to configure AWS CLI and configure in ubuntu

Install AWS CLI
$ sudo apt install awscli -y
To check for the version
$ aws –version
To configure AWS account crdentials
copy the access and secret key from AWS account security credentials
$ aws configure
AWS Access Key ID [None]: *****************Β 
AWS Secret Access Key [None]: ******************
Default region name [None]: ap-south-1
Default output format [None]: json or table or text

How to create AWS EC2 instance using Terraform

create directory ec2 and navigate to the directory
$ mkdir ec2 && cd ec2
create main.tf file
$ vim main.tf

provider "aws" {
region = "ap-south-1"
}

resource "aws_instance" "app_server" {
ami = "ami-03f4878755434977f"
instance_type = "t2.nano"
subnet_id = "subnet-0ccba3b8cfd0645e2"
key_name = "awskey"
associate_public_ip_address = "true"
tags = {
Name = "demo-server"
}
}

output "public_ip" {
description = "public ip of the instance"
value = aws_instance.app_server.public_ip
}

save and exit
initialize the terraform
$ terraform init
$ terraform plan
$ terraform apply -auto-approve
it will create the AWS EC2 instance with output the public ip of the instance

To destroy the instance
$ terraform destroy -auto-approve

How to install Terraform in Ubuntu

Method1: Package manager
$ wget -O- https://apt.releases.hashicorp.com/gpg | sudo gpg –dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
$ echo β€œdeb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main” | sudo tee /etc/apt/sources.list.d/hashicorp.list
$ sudo apt update && sudo apt install terraform
$ terraform version
To get help options
$ terraform -h

Method2: Binary download
download the binary from wget https://developer.hashicorp.com/terraform/downloads
$ wget https://releases.hashicorp.com/terraform/1.6.6/terraform_1.6.6_linux_amd64.zip

extract using unzip
$ unzip terraform_1.6.6_linux_amd64.zip
$ mv terraform /usr/local/bin/
$ terraform version
$ terraform -h

To remove terraform binary method
$ sudo rm -f /usr/local/bin/terraform

To remove terraform package manager method
$ sudo apt remove terraform --purge

How to install AWS EKS Cluster

Β 

step1: create EC2 instance

step2:
Create an IAM Role and attach it to EC2 instance 
IAM 
EC2 
VPC 
CloudFormation 
Administrative access

In the EC2 instance install kubectl and eksctl
step3: install kubectl
$ curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
$ chmod +x ./kubectl
$ sudo mv ./kubectl /usr/local/bin
$ kubectl version --client

step4: install eksctl
$ curl --silent --location "https://github.com/weaveworks/eksctl/releases/latest/download/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp
$ sudo mv /tmp/eksctl /usr/local/bin
$ eksctl version

step5: install aws-iam-authenticator
$ curl -Lo aws-iam-authenticator https://github.com/kubernetes-sigs/aws-iam-authenticator/releases/download/v0.6.14/aws-iam-authenticator_0.6.14_linux_amd64
$ chmod +x ./aws-iam-authenticator
$ mkdir -p $HOME/bin && cp ./aws-iam-authenticator $HOME/bin/aws-iam-authenticator && export PATH=$HOME/bin:$PATH
$ echo 'export PATH=$HOME/bin:$PATH' >> ~/.bashrc
step6:
create clusters and nodes
$ eksctl create cluster --name dhana-cluster --region ap-south-1 --node-type t2.small

step7:
Validate your cluster using by creating by checking nodes and by creating a pod
$ kubectl get nodes
$ kubectl run pod tomcat --image=tomcatΒ 
$ kubectl run pod nginx --image=nginx

To delete the cluster dhana-cluster
$ eksctl delete cluster dhana-cluster --region ap-south-1

AWS CLI for AWS RDS PgSQL

To create postgres DB
$ aws rds create-db-instance --db-instance-identifier demo-postgresql --db-instance-class db.t3.micro --engine postgres --master-username postgres --master-user-password passcode123 --allocated-storage 20

To describe and get the endpoint url
$ aws rds describe-db-instances --db-instance-identifier demo-postgresql | grep Address

To access the remote postgresql
$ psql --host=<endpoint_url> --port=5432 --username=postgres
--dbname=postgres --password

To delete the db instance without final snapshot and automated backups
$ aws rds delete-db-instance --db-instance-identifier demo-postgresql
--skip-final-snapshot --delete-automated-backups

AWS CLI for AWS RDS MySQL

To create a mysql db
$ aws rds create-db-instance --db-instance-identifier demo-mysql --db-instance-class db.t3.micro --engine mysql --master-username admin --master-user-password passcode123 --allocated-storage 20

To describe and get the endpoint url
$ aws rds describe-db-instances --db-instance-identifier demo-mysql | grep Address

To access the remote mysql DB
$ mysql -h <endpoint_url> -P 3306 -u admin -p

To delete the db instance without final snapshot and automated backups
$ aws rds delete-db-instance --db-instance-identifier demo-mysql --skip-final-snapshot --delete-automated-backups

How to modify AWS EBS volume size and use in linux

choose the EBS volume and click modify
give the desired size to extend the volume
in Linux terminal umount the volume
$ sudo umount /dataΒ  (where the ebs volume is mounted)
$ sudo e2fsck -f /dev/xvdf
$ sudo resize2fs /dev/xvdf

mount the volume again
$ sudo mount -a
$ df -Th

tmux

To start a new session
# tmux new -s zha

To login to a tmux session
# tmux a -t zha
or
# tmux attach-session -t zha

# tmux kill-session -t zha
or
# tmux kill-session -t 1

# tmux detach
# tmux attach

freeradius and daloradius webGUI installation ubuntu22.04

update the server
# apt update

install necessary packages
# apt-get install apache2 mariadb-server php libapache2-mod-php php-mail php-mail-mime php-mysql php-gd php-common php-pear php-db php-mbstring php-xml php-curl unzip wget -y

check the php version
# php -v

view versions of FreeRADIUS available
# apt policy freeradius

install freeradius
# apt -y install freeradius freeradius-mysql freeradius-utils

stop the freeradius service
# systemctl stop freeradius.service

To run FreeRADIUS debug mode
# freeradius -X

login to mariadb and create DB , DB user and password
# mysql -u root
> CREATE DATABASE radius;
> GRANT ALL ON radius.* TO radius@localhost IDENTIFIED BY "PASSWORD";
> FLUSH PRIVILEGES;
> QUIT;

check the DB created
# mysql -u root -p -e "show databases;"

download the daloradius webGUI package from github
# wget https://github.com/lirantal/daloradius/archive/refs/tags/1.3.zip

extract the package
# unzip 1.3.zip

rename the folder
mv daloradius-1.3/ daloradius

To populate the database with the daloRADIUS schema. The .sql file is located in the β€˜/contrib/db/’ folder.
we might have to change this path if you didn’t install it in the root destination.
# mysql -u root -p radius < contrib/db/fr2-mysql-daloradius-and-freeradius.sql
# mysql -u root -p radius < contrib/db/mysql-daloradius.sql

move the daloradius folder to /var/www/html
# mv daloradius /var/www/html/

rename the daloradius.conf.php.sample to daloradius.conf.php
# mv /var/www/html/daloradius/library/daloradius.conf.php.sample /var/www/html/daloradius/library/daloradius.conf.php

assign ownership of the daloRADIUS web configuration files to Apache
# chown -R www-data:www-data /var/www/html/daloradius/

configure the permissions of main configuration file to 664
# chmod 664 /var/www/html/daloradius/library/daloradius.conf.php

To allow the DaloRADIUS web interface to access FreeRADIUS,
to provide its database details in the configuration file for DaloRADIUS
add the database details(username, password and db name)
in the below file
# vim /var/www/html/daloradius/library/daloradius.conf.php

$configValues['CONFIG_DB_USER'] = 'radius';
$configValues['CONFIG_DB_PASS'] = 'PASSWORD';
$configValues['CONFIG_DB_NAME'] = 'radius';

:wq! save and exit

restart the freeradius and apache2 and check the status
# systemctl restart freeradius
# systemctl restart apache2
# systemctl status freeradius
# systemctl status apache2

access the daloradius
http://ip-address/daloradius/login.php

default username : administrator
default password : radius
To change the default password
config > operators > list operators > administrator > operator password and apply

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