Pyla's Cloud: August 2025

Friday, 22 August 2025

Ansible_Notes

ansible -i inventory.ini -m ping all # inventory.ini it will ping to the hosts which are in inventory

# ansible -i inventory.ini -m ping all --private-key XXXX.pem -u ubuntu # incase above command didn't work

[web]
ubuntu@52.10.253.174
[db]
ubuntu@44.229.189.58
 
#ansible -i inventory.ini -m ping web 

#ansible -i inventory.ini -m ping db
 

playbook.yaml # To create a directory in defined path

- hosts: web
  become: true
  tasks: 
    - name: Create a directory on remote machine
      file:
        path: ./basic-user-dir
        state: directory
 

Dryrun:

$ ansible-playbook -i inventory.ini playbook.yaml --check --diff

Run:

$ ansible-playbook -i inventory.ini playbook.yaml # --diff to get different

Example2 -

playbook1.yaml # To create a directory in defined path and confirm the dir creation status

ansible-playbook -i inventory.ini Day-1/playbook1.yaml

- hosts: web 
  become: true
  tasks: 
    - name: Create a directory on remote machine
      file:
        path: ./boa-user-dir-3
        state: directory
      register: dir_status  
    - name: print message if dir is created 
      debug: 
        msg: "Directory boa-user-dir is created"
      when: dir_status.changed 

Output-
PLAY [web] *****************************************************************************************

TASK [Gathering Facts] *****************************************************************************
[WARNING]: Platform linux on host ubuntu@52.10.253.174 is using the discovered Python interpreter
at /usr/bin/python3.12, but future installation of another Python interpreter could change the
meaning of that path. See https://docs.ansible.com/ansible-
core/2.18/reference_appendices/interpreter_discovery.html for more information.
ok: [ubuntu@52.10.253.174]

TASK [Create a directory on remote machine] ********************************************************
changed: [ubuntu@52.10.253.174]

TASK [print message if dir is created] *************************************************************
ok: [ubuntu@52.10.253.174] => {
"msg": "Directory boa-user-dir is created"
}

PLAY RECAP *****************************************************************************************
ubuntu@52.10.253.174 : ok=3 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Example2 - Completed

Example3 - Install apache2

pyalbook.yamal2

- hosts: web 
  become: true
  tasks: 
    - name: install apache on web remote machine
      apt: name=apache2 update_cache=yes state=latest

    - name: check the status of installation
      command: systemctl status apache2
      register: apache_status

    - name: print the status
      debug:
        msg: "{{apache_status.stdout}}" 
 

Dry Run:

ansible-playbook -i inventory.ini Day-2/playbook2.yaml --check --diff

PLAY [web] *****************************************************************************************

TASK [Gathering Facts] *****************************************************************************
[WARNING]: Platform linux on host ubuntu@52.10.253.174 is using the discovered Python interpreter
at /usr/bin/python3.12, but future installation of another Python interpreter could change the
meaning of that path. See https://docs.ansible.com/ansible-
core/2.18/reference_appendices/interpreter_discovery.html for more information.
ok: [ubuntu@52.10.253.174]

TASK [install apache on web remote machine] ********************************************************
The following additional packages will be installed:
apache2-bin apache2-data apache2-utils libapr1t64 libaprutil1-dbd-sqlite3
libaprutil1-ldap libaprutil1t64 liblua5.4-0 ssl-cert
Suggested packages:
apache2-doc apache2-suexec-pristine | apache2-suexec-custom www-browser
The following NEW packages will be installed:
apache2 apache2-bin apache2-data apache2-utils libapr1t64
libaprutil1-dbd-sqlite3 libaprutil1-ldap libaprutil1t64 liblua5.4-0 ssl-cert
0 upgraded, 10 newly installed, 0 to remove and 0 not upgraded.
changed: [ubuntu@52.10.253.174]

TASK [check the status of installation] ************************************************************
skipping: [ubuntu@52.10.253.174]

TASK [print the status] ****************************************************************************
ok: [ubuntu@52.10.253.174] => {
"msg": ""
}

RUN:

$ ansible-playbook -i inventory.ini Day-2/playbook2.yaml --diff

Output -

TASK [print the status] ****************************************************************************
ok: [ubuntu@52.10.253.174] => {
"msg": "● apache2.service - The Apache HTTP Server\n Loaded: loaded (/usr/lib/systemd/system/apache2.service; enabled; preset: enabled)\n Active: active (running) since Thu 2025-08-21 05:40:53 UTC; 16s ago\n Docs: https://httpd.apache.org/docs/2.4/\n Main PID: 3564 (apache2)\n Tasks: 55 (limit: 1072)\n Memory: 5.3M (peak: 5.6M)\n CPU: 40ms\n CGroup: /system.slice/apache2.service\n ├─3564 /usr/sbin/apache2 -k start\n ├─3566 /usr/sbin/apache2 -k start\n └─3567 /usr/sbin/apache2 -k start\n\nAug 21 05:40:53 ip-10-0-1-10 systemd[1]: Starting apache2.service - The Apache HTTP Server...\nAug 21 05:40:53 ip-10-0-1-10 systemd[1]: Started apache2.service - The Apache HTTP Server."
}

PLAY RECAP *****************************************************************************************
ubuntu@52.10.253.174 : ok=4 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Validation in console -

ubuntu@ip-10-0-1-10:~$ systemctl status apache2
● apache2.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/apache2.service; enabled; preset: enabled)
Active: active (running) since Thu 2025-08-21 05:40:53 UTC; 1min 52s ago
Docs: https://httpd.apache.org/docs/2.4/
Main PID: 3564 (apache2)
Tasks: 55 (limit: 1072)
Memory: 5.3M (peak: 5.6M)
CPU: 45ms
CGroup: /system.slice/apache2.service
├─3564 /usr/sbin/apache2 -k start
├─3566 /usr/sbin/apache2 -k start
└─3567 /usr/sbin/apache2 -k start

Aug 21 05:40:53 ip-10-0-1-10 systemd[1]: Starting apache2.service - The Apache HTTP Server...
Aug 21 05:40:53 ip-10-0-1-10 systemd[1]: Started apache2.service - The Apache HTTP Server.

Example 3 completed.

Example 4 - executing mail-playbook which is tacking from another file

main-playbook.yaml

- hosts: web
  become: true

  pre_tasks:
     - name: load the background check
       import_tasks: pretask.yaml

  tasks:
     - name: install software
       import_tasks: maintask.yaml 
 

pretask.yaml

- name: check the background of remote machine
  apt:
    update_cache: true
    cache_valid_time: 3600

- name: Gather OS Information
  setup:
    gather_subset:
      - "os_family"

- name: print OS Information
  debug:
    msg: "the underlying OS is  {{ansible_os_family}}"
 

maintask.yaml

    - name: install apache to the web remote machine
      apt: 
        name:
          - apache2 
        state: latest

    - name: chacke the status of installation
      command: systemctl status apache2
      register: apache_status
    
    - name: print the status
      debug:
        msg: "{{apache_status.stdout}}"

Run:

$ ansible-playbook -i inventory.ini Day-2/main-playbook.yaml --diff

Output -

PLAY [web] *****************************************************************************************

TASK [Gathering Facts] *****************************************************************************
[WARNING]: Platform linux on host ubuntu@52.10.253.174 is using the discovered Python interpreter
at /usr/bin/python3.12, but future installation of another Python interpreter could change the
meaning of that path. See https://docs.ansible.com/ansible-
core/2.18/reference_appendices/interpreter_discovery.html for more information.
ok: [ubuntu@52.10.253.174]

TASK [check the background of remote machine] ******************************************************
changed: [ubuntu@52.10.253.174]

TASK [Gather OS Information] ***********************************************************************
ok: [ubuntu@52.10.253.174]

TASK [print OS Information] ************************************************************************
ok: [ubuntu@52.10.253.174] => {
"msg": "the underlying OS is Debian"
}

TASK [install apache to the web remote machine] ****************************************************
ok: [ubuntu@52.10.253.174]

TASK [chacke the status of installation] ***********************************************************
changed: [ubuntu@52.10.253.174]

TASK [print the status] ****************************************************************************
ok: [ubuntu@52.10.253.174] => {
"msg": "● apache2.service - The Apache HTTP Server\n Loaded: loaded (/usr/lib/systemd/system/apache2.service; enabled; preset: enabled)\n Active: active (running) since Thu 2025-08-21 06:13:59 UTC; 52min ago\n Docs: https://httpd.apache.org/docs/2.4/\n Main PID: 11157 (apache2)\n Tasks: 55 (limit: 1072)\n Memory: 5.5M (peak: 5.8M)\n CPU: 174ms\n CGroup: /system.slice/apache2.service\n ├─11157 /usr/sbin/apache2 -k start\n ├─11159 /usr/sbin/apache2 -k start\n └─11160 /usr/sbin/apache2 -k start\n\nAug 21 06:13:59 ip-10-0-1-10 systemd[1]: Starting apache2.service - The Apache HTTP Server...\nAug 21 06:13:59 ip-10-0-1-10 systemd[1]: Started apache2.service - The Apache HTTP Server."
}

PLAY RECAP *****************************************************************************************
ubuntu@52.10.253.174 : ok=7 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Example 4 - End

Example 5: Deploying FASTAPI app with ansible

- hosts: web
  become: true
  pre_tasks:
      - name: update cache
        apt:
          update_cache: true
  tasks:
      - name: install required software
        apt:
           name:
             - python3
             - python3-pip
             - python3-venv
            state: latest

      - name: create FASTAPI dir on remote machine 
        file:
            path: /opt/fastapi_app
            state: directory

      - name: copy FASTAPI to the destination
        copy:
          src: fastapi_app/
          dest: path:/opt/fastapi_app

      - name: create virtual env
        command: python3 -m venv /opt/fastapi_app/venv

      - name: install fastapi on virtual env
        command: /opt/fastapi_app/venv/bin/pip install fastapi uvicorn

      - name: run my application
        shell:
          nohup /opt/fastapi_app/venv/bin/uvicorn main:app --host 0.0.0.0 --port 8000 &
        args:
          chdir: /opt/fastapi_app      

RUN:

~/Documents/python-ansible/ansible-training/Day-2/fastapi_deploy/fastapi_app$ ansible-playbook -i ../../../inventory.ini ../playbook-python.yaml

Output:

PLAY [web] *****************************************************************************************

TASK [Gathering Facts] *****************************************************************************
[WARNING]: Platform linux on host ubuntu@52.10.253.174 is using the discovered Python interpreter
at /usr/bin/python3.12, but future installation of another Python interpreter could change the
meaning of that path. See https://docs.ansible.com/ansible-
core/2.18/reference_appendices/interpreter_discovery.html for more information.
ok: [ubuntu@52.10.253.174]

TASK [update cache] ********************************************************************************
changed: [ubuntu@52.10.253.174]

TASK [install required software] *******************************************************************
changed: [ubuntu@52.10.253.174]

TASK [create FastAPI dir on remote machine] ********************************************************
changed: [ubuntu@52.10.253.174]

TASK [copy FastAPI to the destination] *************************************************************
changed: [ubuntu@52.10.253.174]

TASK [create virtual env] **************************************************************************
changed: [ubuntu@52.10.253.174]

TASK [inastall fast api on virtual env] ************************************************************
changed: [ubuntu@52.10.253.174]

TASK [Run my application] **************************************************************************
changed: [ubuntu@52.10.253.174]

PLAY RECAP *****************************************************************************************
ubuntu@52.10.253.174 : ok=8 changed=7 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Example 5 completed

Ansible Galaxy:

#ansible-galaxy role init role1

role1-playbook.yaml

- hosts: web
  become: true
  roles:
    - role1

\role1\tasks\main.yaml # default file name can not be changed

    - name: install apache to the web remote machine
      apt: 
        name:
          - apache2 
        state: latest

    - name: chacke the status of installation
      command: systemctl status apache2
      register: apache_status
    
    - name: print the status
      debug:
        msg: "{{apache_status.stdout}}"
    
    - name: replace default page with my custom page
      copy:
         src: index.html
         dest: /var/www/html

    - name: Update  page with my custom page
      copy:
         src: update.html
         dest: /var/www/html

#ansible-playbook -i inventory.ini Day-2/role1-playbook.yaml --check

Example 6:

/var/main.yaml controls the installation

Example 7: Adding additional conditions

Print - only OS kernal version is gt 20

Example 8:

Example 9: Add additional tasks on subtask.yaml and import. subtasks for checking OS family and memory

in main.yaml - add -

- import_tasks: subtask.yaml

Example 10:

Ignoring error and go to next task.

Example 11: using jinja

Example 12: using handler

Vaults:

Thursday, 21 August 2025

Python Notes

$ python --version
Python 3.12.3

Python is platform independent

python virtual machine:

The Python Virtual Machine (PVM) is an abstract machine and a crucial component of the Python runtime environment. It is responsible for executing Python bytecode, which is a low-level, platform-independent representation of Python source code.

It supports Virtual Environment :

Create virtual environment :

$python3 -m venv myvenv #Will install on current folder

Activate virtual environment:

$ source myvenv/bin/activate

deactivate #To deactive

(myvenv) HostName@Current folder:

print('Welcome to python training')

PIP:
pip (also known by Python 3's alias pip3) is a package manager (package management system) written in Python and is used to install and manage software packages.

pip install fastapi[all]

pip freeze > requirements.txt

pip install requirements.txt

pip list

Variables:

 
username = "Praveen"
city = "Hyderabad"
state = 'TG'
age=40

print(f"Myname is {username} I am from {city} {state} and my age is {age}")

 
data1=int(input('Enter your value-1: '))
data2=int(input('Enter your value-1: '))
print(f"Total: {(data1) + (data2)}")
print(type(data1))
 
Conditions: 
 
if age>30:
    print('your allowed to enter')
else:
    print('Not Allowed')
  
If Condition with iteration:  

while True:
        try:
            age = int(input("Enter your age: "))
            if 0 <= age <= 101:
                break
            else:
                print("Please enter a valid age between 0 and 101.")
        except ValueError:
            print("Invalid input! Please enter a number.")
print(f"Your age is: {age}")
 

####################  Array  ####################

# array declarations 
 
usernames = ['Bramha','Vishnu','Mahesh']

print(usernames)

# ['Bramha', 'Vishnu', 'Mahesh']

for username in usernames:
    print(f"User Details : {username}")

for userindex,username in enumerate(usernames):
    print(f"Index : {userindex} --> {username.upper()}")


for userindex,username in enumerate(usernames,start=1):
    print(f"Index : {userindex} --> {username.upper()}")
Problem - Created and fill array with user input:

# initiating empty array
user_data =[]

data = int(input("How many numbers to add: "))

for i in range(data):
    num = int(input(f" Enter number : "))
    user_data.append(num)
print(f"values is array: {user_data}")

# calculate even or odd

for num in user_data:
    if(num%2==0):
        print(f"{num} is even")
    else:
        print(f"{num} is odd")


# calculate the addition if all numbers
res = 0
for num in user_data:
    res +=num
print(f"addition res = {res}")
 
 
# Get Positive input 
 
def get_positive_input(prompt):
    while True:
       
            value = int(input(prompt))
            if value > 0:
                return value
            else:
                print("Enter a positive value greater than 0.")
        


data1 = get_positive_input("Enter your value-1: ")
data2 = get_positive_input("Enter your value-2: ")

# Addition
c = data1 + data2
print(f"Addition is: {c}")


#################### Functions  ####################
 
# Declare function

def showwelcome():
    print("Welcome to the function")

showwelcome()

def calculatedata(x,y):
    return print(x+y)

calculatedata(3,2)

def multireturndata(x,y):
    return x,y

a,b = multireturndata(2,5)
 
#################### Class #################### 

class user:
    def showwelcome(self):
        print("Welcome to the class")

    def calculatedata(self,x,y):
        print(f"Addition is {x+y}")

# using class
uc = user()
uc.showwelcome()
uc.calculatedata(2,3)

#########
 

class user:

    def __init__(self):   # __int__ - Constructor. It is self called 
        print('Defult constructor called')

user = user()

#output - Defult constructor called

class user:
    def __init__(self,uname,email,city):
        self.uname = uname
        self.email = email
        self.city  = city

user = user('Praveen','praveen@mail.com','Hyd')

print(user.uname,user.email,user.city)

#Output - Praveen praveen@mail.com Hyd

class user:
    def showcity(self):         # Defined the function, not self Constructor
        city = input('Enter city : ')
        print('city will be called ', city)

user = user()   # Loading call 
user.showcity() # Calling method 

#Output - Enter city : Hyderabad / city will be called  Hyderabad


class user:
    def __init__(self,uname,email,city):
        self.uname = uname
        self.email = email
        self.city  = city
    
    def __str__(self):       # This function auto called when your printing object
        return f"{self.uname} - {self.email} - {self.city}"
user = user('Praveen','praveen@mail.com','Hyd')

print(user)

#output - Praveen - praveen@mail.com - Hyd

 #####
 
### ribclass.py ### 
 
from abc import ABC,abstractmethod

class RBI(ABC):
    @abstractmethod         # abstractmethod means mandatory in chaild class
    def withdraw(self):
        pass
    @abstractmethod
    def deposit(self):
        pass
    @abstractmethod
    def checkBalance(self):
        pass
    
    def openSalaryAccount(self):  # No abstractmethod so this function not mandatory in clild
        pass
 ### ribclass.py closed ###
 
 ### sbiclass.py ####
 
from rbiclass import RBI    # Importing RBI class from rbiclass.py file 

class SBI(RBI):
    def withdraw(self):
        print("withdraw from SBI")
     
    def deposit(self):
        print("deposit from SBI")
     
    def checkBalance(self):
        print("checkbalance from SBI")
        
    def openFD(self):
        print('FD account opened in SBI')
 
### sbiclass.py closed ###
 
### Bankingmail.py ##### 
 
from sbiclass import SBI  # Importing SBI class from sbiclass.py file

bank1 = SBI()
bank1.checkBalance()
bank1.openSalaryAccount()
bank1.deposit()
 
### Bankingmail.py closed ##### 
 
# Output - checkbalance from SBI / deposit from SBI 
 
  
 ############ FASTAPI ###########
 
from fastapi import FastAPI

app = FastAPI()

users = ['Admin','Manager','QA']

@app.get("/Welcome")
def Show_Welcome():
    return{"Message":"Welcome to FASTAPI"}

# RUN - /Documents/python-ansible/python-training/day-2/fastapi$ uvicorn crudapp:app

@app.get("/loadusers")
def showusers():
    return {"message":users}


# Troubleshoot - sudo lsof -i :8000; kill -9 <PID>
 
###########
 
# database.py - File  

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

SQL_DB = "sqlite:///./mytest.db"

engine = create_engine(
    SQL_DB, connect_args={"check_same_thread": False}

)
SessioLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()


def get_connection():
    db = SessioLocal()
    try:
        yield db
    finally:
        db.close()



-----
# schema.py - file name

from pydantic import BaseModel

# the data you are expecting from the client
class Base(BaseModel):

    name: str
    sclass: str
    section: str


---
# models.py - File name

# schema represenation

from sqlalchemy import Column,String
from .database import Base

class Student(Base):
    __tablename__="STUDENT"

    name= Column(String,primary_key=True)
    sclass= Column(String)
    section= Column(String)

class staff(Base):
    __tablename__="STAFF"

    name= Column(String,primary_key=True)
    sclass= Column(String)
    section= Column(String)


---
#studentapp.py - File

from fastapi import FastAPI,APIRouter,Depends,status
from fastapi.params import Body
from sqlalchemy.orm import Session
from .. import schema,models
from .. database import engine,get_connection



router= APIRouter(tags=["Student Application"])

@router.post("/addstudent")
def studentRegister(student:schema.Base, db:Session=Depends(get_connection)):
    newdata = models.Student(**student.dict())
    db.add(newdata)
    db.commit()
    return {"message":"db created"}

@router.post("/addstaff")
def staffregister(staff:schema.Base, db:Session=Depends(get_connection)):
    newdata = models.staff(**staff.dict())
    db.add(newdata)
    db.commit()
    return {"message":"staff created"}

-----
# Crudapp.py - File

from fastapi import FastAPI
from .routers import studentapp

from .database import engine,get_connection
from . import models,schema

# create table in db while loading model class
models.Base.metadata.create_all(bind=engine)
app=FastAPI()

app.include_router(studentapp.router)
 
 
######
 
 
 
 
 
 

Key Difference Between List, Array and Tuple

Feature	List	Array	Tuple
Mutability	Mutable	Mutable	Immutable
Data Type	Can store different types	Stores elements of the same type	Can store different types
Ordered	Yes	Yes	Yes
Performance	Slower for numerical operations	Faster for numerical operations	Faster than lists (due to immutability)
Memory Efficiency	Less efficient	More efficient for large data	More memory-efficient than lists
Usage	General-purpose collection	Numerical and homogeneous data	Fixed data, constants
Syntax	[ ]	array()	( )
Indexing	Supported	Supported	Supported

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Friday, 22 August 2025

Ansible_Notes

Thursday, 21 August 2025

Python Notes

Key Difference Between List, Array and Tuple

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