DevOps Classroomnotes 11/Sep/2022

Exercises

Create a new folder anywhere in your system and make it a git repo
Create 3 folders and check for status
now add a file in first folder and then execute git status
add this change to staging area
create one more file in second folder and add this change also to staging area
Now commit the change
Draw a tree like what we have done in the class git log --oneline
Now create two files in third folder, add them to staging area and now remove one file from staging area and create 2 commit.
Update your tree
now add the file which you moved from staging area to working tree back to staging ared and then create a third commit
Now create two files each in three folders add all of them to staging area
Clean the above changes as if you have not done any changes after 3 commit.

Git is a Stupid Content Tracker
Linus Torvalds has a built a new file system which can track contents
Lets understand how git works
When we initialize git repository
- .git folder gets created
- HEAD pointer points to a default reference which is master
- Reference will point to a specific commit id
Create a first commit on some folder after initalization.
Now lets use a plumbing command git cat-file
- git cat-file -t shows the type
- git cat-file -p shows the contents
Git uses SHA-1 Hash to store objects.
Git has following object types
- tree => folder
- blob => file
- commit
Lets find out the type and contents of commit id
Now lets find the contents of tree
Lets find the contents of file i.e. blob main.py
main.py is empty
Now lets some content and create a second commit
please refer video for the rest of images on how git works.

Git by default create a branch which is called as master
Branch will point to a latest commit done in it.
To create a new branch from existing branch git branch <branch-name>
Now lets make some changes in rel_1.0_siemens, to do this HEAD should be pointing towards rel_1.0_siemens for this we use checkout
Now lets add some changes as discussed in the class
Next Steps:
- A change done in the master branch should be made available to both siemens and ge branch
- A commit in ge branch should also be applied to siemens branch
- Adding multiple users i.e.Remote Repository
  - pull
  - fetch
  - push
  - remote branches
  - remote repos
  - origin
- All the changes done for siemens and ge to be merged to common branch
- The above activities can be address
  - merge
  - rebase
  - cherry pick
  - merge – conflicts