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Day 7 : 16th Apr. 2025

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Version Control System using GIT & GitHub ::::

Developer :

index.html

payment.java

IDE -

index.html

-----

---

-

-

-

-

-

-

---

-----

save the file as index.html

Testing

Open index.html

-----

---

-4545

3434534

-345345345

-34534

-345345345

-

-asdfsd

---

-----

save the file as index.html

Testing

Open index.html

-----

---

-4545

3434534

-345345345hhh

-34534hhhh

-345345345

-hhh

-asdfsd

---

----- hhhhh

save the file as index.html

Testing

Version Control System :

- Is used to version control the source code Changes

- Is used to track the source code changes

Using Version Control System like GIT :

index.html

-----

---

-

-

-

-

-

-

---

-----

save the file as index.html ==> index.html_v1.0

-----

---

-4545

3434534

-345345345

-34534

-345345345

-

-asdfsd

---

-----

save the file as index.html ==> index.html_v1.1 --> v1.1 - version_no,tag,commit_id

save the file as index.html ==> index.html_v1.2

save the file as index.html ==> index.html_v1.3

save the file as index.html ==> index.html_v1.4

save the file as index.html ==> index.html_v1.5 --> Latest Version

Types of VCS :

- Local VCS

- Centralized VCS

- Distributed VCS

Distributed Version Control System :

Git :

- Git is one of the open-source distributed version control systems

- It is used to Track the Changes

- Used to Version Control the Source Code Changes

- GIt is used to enable parallel Development using Git Branching

Working with GIT :::

- Install git cli in local machine

- Create GitHub Account

- Install Visual Studion Code.

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Day 8 : 17th Apr. 2025

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Version Control System using GIT :::

Working with Git :::

Developers' Workload ???

- Enhancement Projects / Bug fixing # Existing Project - Source Code is already available in the Remote Repository

- New Project

Repository ==> Collection of Files and Folder - version controlled in local/remote environments

Git file Workflow :::

Local Machine Remote Server

Install Git Client (VCS) (GitHub)

Working Directory Staging Area Local Repository Remote Repository

index.html ---------------> index.html ---------------> index.html_v1.0 ---------------> index.html_v1.0

git add git commit git push

index.html ---------------> index.html ---------------> index.html_v1.1 ---------------> index.html_v1.1

git add git commit git push

index.html ---------------> index.html ---------------> index.html_v1.2 ---------------> index.html_v1.2

git add git commit git push

index.html ---------------> index.html ---------------> index.html_v1.3 ---------------> index.html_v1.3

git add git commit git push

index.html ---------------> index.html ---------------> index.html_v1.4 ---------------> index.html_v1.4

git add git commit git push

git cli commands :::

git clone # To copy/clone the entire remote repository to local machine

git add # To add the changes from Working Directory to Staging Area

git commit # To Commit the Changes from Staging Area to Local Repository

git push # To push the changes from Local Repository to Remote Repository

git fetch/git pull #

- Both git fetch and git pull are used to handle the incremental changes from remote repository

- git fetch :

git fetch is used to just check for the incremental changes. If there is any incremental changes present in the remote repository, the information about the incremental changes will be updated only in the Local Repository. The Actual File Changes will NOT be updated in the Working Directory. Later the changes can be explicitly merged to Working Directory using Branches. using git merge/git pull

- git pull :

git pull is used to check for the incremental changes. If there is any incremental changes present in the remote repository, the information about the incremental changes will be updated in the Local Repository as well as in the Working Directory.

git pull = git fetch + git merge

Fork # To Copy one Remote Repository to Another Remote Repository

git init # To initialize a local git repository

# Creates .git Directory

# Creates a default branch called - main/master

Working with Local Git Client ::::

1. Install git client in Local Windows Machine ? ::::

64-bit Git for Windows Setup # https://git-scm.com/downloads/win

- git bash # meant for Linux Users

- git CMD # meant for Windows Users

- git GUI

Windows User - Open Git Bash !

git --version

Mac / Linux Users :

Open the terminal > git --version

Repository Structure ::::

Project Folder/Workspace :

- Java_Web_App_Project1 # Root Directory

- SRC

- Test

- prop

Open git bash :

cd d:

mkdir SA-DevOps-AI

cd SA-DevOps-AI

mkdir repo1

cd repo1

git init

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Day 9 : 21st Apr. 2025

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Working with Git CLI Commands :

git init

git status # get the current status of git repository

Local Machine Remote Server

Install Git Client (VCS) (GitHub)

Working Directory Staging Area Local Repository Remote Repository

file1.txt ---------------> file1.txt ---------------> file1.txt ---------------> index.html_v1.0

git add git commit git push

git init

git status

echo "rec1" >> file1.txt

git add file1.txt

git commit -m "Created file1.txt"

git log # Is used to get the list of commits in current branch

Git Config :

Local Configuration: # within a specific repository

git config user.name "Loksai"

git config user.email "[email protected]"

Global Configuration # Applicable to all the Repositories.

git config --global user.name "Loksai"

git config --global user.email "[email protected]"

For the Very first commit :

git init

git config --global user.name "Loksai"

git config --global user.email "[email protected]"

git status

echo "rec1" >> file1.txt

git add file1.txt

git commit -m "Created file1.txt"

git log # Is used to get the list of commits in current branch

ls # Linux Command to get the list of files/Dirs

git ls-files # get the list of files that being tracked by git from staging / local repository

GIT Add Command ::::

git add <file_name>

git add <file1_name> <file2_name>

git add *.java *.html

git add . # Add all untraced changes/files to staging area

Un-Stage:::: # Undo the changes from Staging area.

# From Staging area, the Changes will be back to working directory.

git rm --cached s1.txt # It will just remove the changes from staging and take the changes back to working directory

git rm -f s2.txt # It will remove the file permanently from staging area as well as from the working directory

Git Log ::::

git log # Is used to get the list of commits in current branch

git log --oneline # Get the list of commit with short commit id and message

git log --oneline -3 # To get the last 3 Commits

git log -3

git log --stat -1

git show <commit_id> # Get the details of the commit at the record level

git diff # Get the difference between the new changes and the committed changes

Undo the Committed Changes :::

- git reset :::

git reset is used to undo the changes from the repository

git reset will reset the commit point to the previous commit point

git reset will not create any new commit point for track purpose

git reset is not recommended in the shared repository

Syntax :

- git reset <reset_option> <previous_Commit_ID>

Reset Options ::

git reset --soft <previous_Commit_ID> :::

- git reset will reset the HEAD pointer to the previous commit point.

- It will take the changes back to staging area

- The Changes will be available in staging area and working directory

git reset --mixed <previous_Commit_ID> ::: # Default

- git reset will reset the HEAD pointer to the previous commit point.

- It will take the changes back to working directory

- The Changes will be available only in working directory

git reset --hard <previous_Commit_ID> :::

- git reset will reset the HEAD pointer to the previous commit point.

- It will permanently delete the files from the system

Commit Points :

5 # Latest Commit

4

3

2

1

git reset --hard 3

3

2

1

501 cd d:

502 cd SA-DevOps-AI

503 ls

504 cd SA-clear

505 clear

506 pwd

507 ls

508 cd SA-DevOps-AI-17/

509 clear

510 ls

511 cd sample-repo

512 cd sample-repo1/

513 cd ..

514 cd sample-repo2/

515 clear

516 cd ..

517 cd sample-repo1/

518 ls

519 ls -a

520 cd ..

521 ls

522 rm -rf sample-repo*

523 ls

524 mkdir repo1

525 clear

526 cd repo1/

527 clear

528 pwd

529 git init

530 ls -a

531 cd .git/

532 ls

533 cd ..

534 clear

535 ls

536 ls

537 git status

538 ls

539 echo "rec1" >> file1.txt

540 ls

541 git status

542 git add file1.txt

543 git status

544 git commit -m "Created file1.txt"

545 git log

546 ls

547 echo "rec1" >> file2.txt

548 ls

549 git status

550 git add file2.txt

551 git commit -m "Created file2.txt"

552 git status

553 git log

554 cd d:

555 cd SA-DevOps-AI-17/

556 ls

557 mkdir repo2

558 clear

559 cd repo2/

560 clear

561 pwd

562 git init

563 git status

564 ls

565 clear

566 echo "rec1" >> f1.txt

567 ls

568 git status

569 git add f1.txt

570 git status

571 git commit -m "Created f1.txt"

572 git status

573 git log

574 echo "rec1" >> f2.txt

575 git add f2.txt

576 git commit -m "Created f2.txt"

577 git log

578 clear

579 git log

580 git config --global user.name "Loksai"

581 ls

582 echo "rec1" >> f3.txt

583 git add f3.txt

584 git commit -m "Created f3.txt"

585 git log

586 cd ..

587 ls

588 cd repo1/

589 git log

590 echo "rec1" >> file3.txt

591 git add file3.txt

592 git commit -m "Created file3.txt"

593 git log

594 clear

595 cd ..

596 mkdir repo3

597 cd repo3/

598 clear

599 git status

600 git init

601 git status

602 clear

603 ls

604 git status

605 git log

606 clear

607 echo "rec1" >> s1.txt

608 git status

609 clear

610 git status

611 git add s1.txt

612 git status

613 clear

614 ls

615 git ls-files

616 git status

617 git commit -m "Created s1.txt"

618 git status

619 git log

620 git ls-files

621 ls

622 echo "rec1" >> s2.txt

623 ls

624 git ls-files

625 git status

626 git add s2.txt

627 ls

628 git ls-files

629 clear

630 git status

631 git commit -m "Created s2.txt"

632 clear

633 ls

634 git status

635 clear

636 ls

637 echo "s3.txt"

638 ls

639 echo "rec1" >> s3.txt

640 clear

641 git status

642 ls

643 echo "rec1" >> s4.txt

644 echo "rec1" >> s5.txt

645 echo "rec1" >> s6.txt

646 git status

647 echo "rec1" >> a1.java

648 echo "rec1" >> a2.java

649 echo "rec1" >> a3.java

650 echo "rec1" >> a4.java

651 echo "rec1" >> q1.doc

652 echo "rec1" >> q2.doc

653 echo "rec1" >> q3.doc

654 echo "rec1" >> l1.html

655 echo "rec1" >> l2.html

656 echo "rec1" >> l3.html

657 git status

658 git add a1.java l1.html

659 git status

660 git add *.java *.html

661 git status

662 git add .

663 git status

664 git ls-files

665 git commit -m "Created somefiles"

666 clear

667 echo "rec1" >> k1.txt

668 git add .

669 git status

670 echo "rec1" >> t1.txt

671 git add .

672 git status

673 git rm --cached k1.txt

674 git ls-files

675 git status

676 git add .

677 git status

678 git rm -f k1.txt

679 ls

680 git status

681 git rm -f t1.txt

682 git status

683 clear

684 git log

685 echo "rec1" >> i1.txt

686 git add .

687 git commit -m "Created i1.txt"

688 echo "rec1" >> i2.tx

689 git add .

690 git commit -m "Created i2.txt"

691 echo "rec1" >> i3.txt

692 git add .

693 git commit -m "Created i3.txt"

694 echo "rec1" >> i4.txt

695 git add .

696 git commit -m "Created i4.txt"

697 clear

698 ls

699 clear

700 git status

701 clear

702 git log

703 clear

704 git log

705 git log --oneline

706 git log --oneline -3

707 git log --oneline -2

708 git log --oneline -1

709 git log --oneline

710 git log --oneline -5

711 git log -2

712 clear

713 git log --stat -1

714 git log -1

715 git log --oneline -1

716 git show f164927

717 clear

718 git status

719 ls

720 clear

721 cat a1.java

722 echo "rec2" >> a1.java

723 cat a1.java

724 git status

725 git diff

726 clear

727 ls

728 cd ..

729 mkdir repo4

730 clear

731 ls

732 cd repo4/

733 clear

734 git init

735 echo "rec1" >> q1.txt

736 git add .

737 git commit -m "CM1"

738 echo "rec1" >> q2.txt

739 git add .

740 git commit -m "CM2"

741 echo "rec1" >> q3.txt

742 git add .

743 git commit -m "CM3"

744 echo "rec1" >> q4.txt

745 git add .

746 git commit -m "CM4"

747 echo "rec1" >> q5.txt

748 git add .

749 git commit -m "CM5"

750 clear

751 git log --onelines

752 git log --oneline

753 ls

754 git ls-files

755 git status

756 git log --oneline

757 git reset --soft 4e1b027

758 git status

759 ls

760 git ls-files

761 git log --oneline

762 git commit -m "CM5.1"

763 ls

764 git ls-files

765 git status

766 git log --oneline

767 git reset --mixed 4e1b027

768 git status

769 ls

770 git ls-files

771 git log --oneline

772 git add .

773 git commit -m "CM5.2"

774 ls

775 git ls-files

776 git status

777 git log --oneline

778 git reset --hard 4e1b027

779 ls

780 git ls-files

781 git status

782 git log --oneline

783 git reset --hard 4b173c6

784 git log --oneline

785 ls

786 git ls-files

787 git status

788 git reset --hard 782846b

789 git status

790 git ls-files

791 ls

792 git log --oneline

793 clear

794 git log --oneline

795 ls

796 cd ..

797 history

Next :::

- git revert :::

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Day 10 : 22nd Apr. 2025

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GIT Revert ::

- Git Revert is same as git reset --hard option

- git revert is used to undo a specific commit

- git revert will create a new commit point for tracking purpose.

- git revert will maintain the commit history

- git revert is recommended in shared repositories

Syntax ::

git revert <specific_Commit_ID>

Eg.:

git revert 018f99a

Create a Commit Point using a commit message

GIT IGNORE :::

- Used to Ignore the files from tracking

- If you don't want git to track any file. using git ignore!

.gitignore --> save the file names to be ignored.

- As a best practise, .gitignore should be the very initial commit.

vi .gitignore

$ cat .gitignore

sample.txt

app.war

target/

s1.doc

*.md

git add .

git commit -m "Initial Commit"

Java_Web_App_Project

SRC

main.java

test.java

app.properties

target

mywebapp.war

DB_Secret

DB_USer_Name

DB_Password

GIT Branch :::

GIT Branching Strategies :

Create GIT Branches :::

Working with git branches enabling parallel development :

GIT Branching Techniques ::::

In Distributed VCS, Branches are used to perform parallel Development

Default Branch - master/main - is considered as a production version of source code.

GIT Branching Strategies :::

- It is used to maintain the integrity of master/main branch

- Git Branch is the logical copy of the default branch

Repo1 :

master - rel1,rel2,rel3

rel1,rel2,rel3,rel4 # rel4 is - feature_branch1 changes upon merge

feature_branch1 - rel1,rel2,rel3,f1cm1,f1cm2,f1cm3

Scenario 1 :

Repo1 :

master - cm1,cm2,cm3

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3,f2cm1,f2cm2,f2cm3 ==> Upon Merging feature1 & feature2

feature1 - cm1,cm2,cm3

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3

feature2 - cm1,cm2,cm3

- cm1,cm2,cm3,f2cm1,f2cm2,f2cm3

Create Branch

git branch # Used get the list of branches

git branch <new_branch_name> # Create New Branch

git switch -c <new_branch_name> # Create New Branch

git switch <branch_name> # Switch to any existing branch

git merge # Used to Merge the Changes to Target Branch

# Should be executed from the target branch

git merge feature1 # Should be executed from the target branch

How Merge Conflict Occurs ::

- When more than one user/feature try to update a same line in the same file on the same target branch, merge Conflict Occurs.

How to fix the Merge Conflict ::

1. Identify the file(s) causing the Merge Conflict

2. Open and review the file content

3. Upon review, decide which record should be retained or deleted from that file

4. Open the File in edit mode, and delete the header and footer lines, and update the file with required records and save it.

5. perform git add and commit to the target branch

Next :

GIT REBASE :

GIT SQUASH :

GIT STASH :

Handling Remote GIT Repositories :

Accessing GITHub Repositories using Visual Studio Code :

- Install Visual Studio Code

- Github Account Account

#######################

Day 11 : 23rd Apr. 2025

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GIT REBASE :

- git rebase :::

- Rebase is used to maintain linear commit history

- Rebase is used to keep the current branch in-sync with target branch

- Rebase can prevent merge-conflicts in the target branch

- As a best practise, it is always recommended to use rebase before merge

Repo1:

master - cm1,cm2,cm3

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3 # Upon merging feature1

- cm1,cm2,cm3,f2cm1,f2cm2,f2cm3,f1cm1,f1cm2,f1cm3 # Upon merging feature2 without proper rebase.

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3,f2cm1,f2cm2,f2cm3 # Expected commits - with proper rebase.

feature1 - cm1,cm2,cm3

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3

git switch master

git merge feature1 ==>

feature2 - cm1,cm2,cm3

- cm1,cm2,cm3,f2cm1,f2cm2,f2cm3

git rebase master # Should be executed from the current branch

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3,f2cm1,f2cm2,f2cm3

git switch master

git merge feature2 ==>

GIT SQUASH :

- It is used to combine the commits into a single commit point.

Repo1:

master - cm1,cm2,cm3

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3,.............................................,f1cm150 # Upon merging without --squash option

feature1 - cm1,cm2,cm3

- cm1,cm2,cm3,f1cm1,f1cm2,f1cm3,.............................................,f1cm150

git switch master

//git merge feature1 ==>

git merge --squash feature1

git commit -m "committed from feature1"

GIT STASH :

- It is used to save the uncommitted changes to the temporary area.

git stash save "msg" # Create an entry in the stash list

git stash list # Get the list of item from the stash list

git stash apply # Apply/Copy the Latest entry from stash list back to staging area

git stash apply stash@{2} # Apply/Copy a specific entry from stash list back to staging area

git stash pop # move the Latest entry from stash list back to staging area

git stash pop stash@{2} # move a specific entry from stash list back to staging area

git stash drop # Delete the Latest entry from stash list

git stash drop stash@{2} # Delete a specific entry from stash list

git stash clear # Clean-up / Delete all the entries from stash list

800 mkdir testrepo1

801 cd testrepo1/

802 git init

803 clear

804 git status

805 echo "rec1" >> q1.txt

806 git add .

807 git commit -m "CM1"

808 echo "rec1" >> q2.txt

809 git add .

810 git commit -m "CM2"

811 echo "rec1" >> q3.txt

812 git add .

813 git commit -m "CM3"

814 echo "rec1" >> q4.txt

815 git add .

816 git commit -m "CM4"

817 clear

818 git log --oneline

819 clear

820 git status

821 ls

822 git ls-files

823 git log --oneline

824 git show 018f99a

825 git revert 018f99a

826 ls

827 git ls-files

828 git status

829 git log

830 git log --oneline

831 git ls-files

832 git revert 279f689

833 ls

834 git ls-files

835 git lg --oneline

836 git log --oneline

837 ls

838 git show 917b6ae

839 git revert 917b6ae