session-11.txt

Project configuration
----------------------
create a server
installed programming language
downloaded code/application
created directories, users
installed dependencies
start application

deployment/release
-------------------
developer will push new app/code
stop the server
remove/backup the old code
download new code
start the server


manual process
----------------------
downtime
time consuming --> 30min
manual mistakes
troubleshooting
who did the mistakes
repeated work

take 1 by 1 from the farm to house 

through lorry --> learning curve, we need to learn driving

coding --> learn scripting
---------------
programming --> java, .net, python
scripting --> shell, python, ansible, terraform, kubernetes, etc.

coding --> patterns and methods

variables
data types
conditions
functions
loops

algorithm thinking
---------------------

1. 10 public sessions, 11th session private


1. first we need to get today's session no
2. if today's session is greater than 10, we need to say it is private
3. less than 10 public


today session = 5

if (today session) > 10
	print("private")
else
	print("public")
	
install git through scripting
--------------------------

1. check user have sudo access or not
2. if not sudo, we will throw error,
3. if sudo proceed
4. install package git
5. we need to check explicitly installed or not
6. if error installation throw the error to user, otherwise say success.


shell scripting
--------------------------
where to keep the scripts???

10 devops engineers
--------------------
one central location to do and share the things

Git --> global information tracking system

version control --> 10 days

after 10 days --> I wanted to see what was script at 2nd day..

we should always go back to previous version if something goes wrong

track the changes --> through git we can understand who did that and why

review the changes --> our team members should review

backup and security

branching --> create a branch from master, do the changes, if everything is good then proceed

collabaration

GIT is a popular decentralised version control system
------------------
decentralised/distributed vs centralised

git repo --> store the code

repository --> some storage just like folder with some extra capabilities

https://github.com/daws-76s/test-repo.git

push --> authentication

username/password --> frequently we need to enter password every time
username/key --> it will be automatically taken from private key

place your public key in the server
keep private key with you

.ssh --> usually in user directory
/c/Users/sivakumar/.ssh

config --> no extensions to this file

git --> concept

github --> they took that concept and created github
gitlab
bitbucket

https://github.com/daws-76s/test-repo.git --> username and password
git@github.com:daws-76s/test-repo.git --> just private key

~ --> your home folder

/c/Users/ramesh

/c/Users/user/daws-76s-github


Host github.com
  HostName github.com
  User git
  PreferredAuthentications publickey
  IdentityFile ~/<replace-your-file-name>


git init --> intialises a folder as git repo

git status --> we can know what is the status of our files

git add --> 

100 scripts

signup, login, forgot password

temp area --> select what is completed and push to git

signup --> add to it temp area and push to git

git config --global user.name "your-user-name"
git config --global user.email "your-email-id"

git commit -m "as part of bug fix" --> till here local...

signup for github
create or use existing pub/private key
place pub key in github
keep private key
create .ssh folder in home directory
create config file without extensions in .ssh folder

make sure you give your username and email before commit.


Host github.com
  HostName github.com
  User git
  PreferredAuthentications publickey
  IdentityFile ~/<replace-your-file-name>
  
1. create repo in github

IDE --> integrated development environment

master --> PROD

duplicate file, edit that, check that and then proceed

create another branch --> do changes --> test changes --> merge

master --> slave

main --> this is PROD branch

feature-123