Git

From Wikipedia - The source code for Git refers to the program as “the information manager from hell”. (in fact, “Git tzu Gehinom” means “go to hell” in Yiddish).

Summary

Summarizing old collections of notes to track the logic behind code versioning in general and git. Not a trustful guide.

.gitconfig

Work in progress..

Actions

Coding > Adding code > Code is in STAGING AREA > Commit code > Push to GitHub

Remember that the HEAD is the pointer.

  • git init

  • git status

  • git add . or git add main.py

  • git log: commit ID, author, date

    • git log --oneline: lookup the hash ID

Commit

  • git commit -m "message" -m "additional notes" atomic changes
    • You can’t switch branches without commits
    • Check the stashing of files
    • git restore: undo a commit
  • git commit -am "message
  • git commit --amend -m "git notes, pull codechange the name of the last commit message

Each commits are linked to the previous commit. Check HEAD to show where the code is pointing.

  • git config --global: user.name, user.email

Reverting a commit (come tornare indietro di commit)

  • git revert HEAD annull the last commit
  • git revert <commit_hash> annull a specific commit generates a new commit by default safer for remote branches

Resetting a commit (come tornare indietro di commit)

less safe for shared branches than revert

  • git reset --soft HEAD~1 removes the last commit but keeps the changes staged (in the index).
  • git reset --mixed HEAD~1 removes the last commit and unstages the changes, but keeps them in the working directory. This is the default behavior if you omit the option.
  • git reset --hard HEAD~1 Removes the last commit and discards all changes in the working directory and staging area. ⚠️ This is destructive—use with caution!

Branching

  • git branch branch-name: creating new branch
    • git switch -c branch-name: build a branch and move to it
    • git checkout -d branch-name: build a branch and move to it
  • git checkout dev-branch or git switch You can move stashed code between branches, check git stash
  • git branch -M newname: renaming branch

Checkout

  • git checkout [ hash ]: move between commits (use hash id) or branches
  • Moving back to the previous commit using git reflog or git checkout branch-name
  • git log --oneline to check the hash

Merging dev files to main

  • git checkout main: not only used for merging, you can move between commits with checkout
  • git merge dev
  • git branch -d dev: Deleting the branch
  • After branching is usual to do a commit

Diff

  • git diff: diff between staged and unstaged of the same files or between commits or between branch of the same file
    • you need to read plus and minus symbols with the direction of files in mind
    • not alway plus means adding code
    • git diff --staged: diff staged and unstaged files
    • git diff [commitid] [commitid] or git diff [commitid]..[commitid]: diff between commits

Stashing

  • git stash: temporary way to save changes

    • git stash pop: bring up stashed code
    • git stash list
    • git stash apply: to apply a specific stash, use stash list to see the id

  • git restore: go back of a commit to undo the current changes

Rebase

Powerful merge tool. Be aware. git rebase takes the branch and attach it to the last commit of the base branch.

main ---- M1 ---- M2 ---- M3
          \____ bugfix ____ B1

After rebase

main ---- M1 ---- M2 ---- M3 ---- B1

Only use it from the side branch like a bug fix. After you checkout in side branch then you can go with: git rebase master

Remote repository

  • git remote - Shows configured remotes.

  • git remote -v - Shows remotes with their respective URLs.

  • git remote add <name> <url> - Adds a new remote.

    • origin name of remote repository

  • git remote rename <old> <new> - Renames a remote.

  • git remote remove <name> - Removes a remote.

  • git remote set-url <name> <new-url> - Changes the URL of a remote.

  • git remote show <name> - Details about a remote.

  • git remote prune <name> - Removes obsolete references.

  • git remote update - Updates all configured remotes.

Pushing code

  • git push -u origin main - pushing a branch to the remote branch origin saving origin as a upstream of main.
    • git push origin main - without the -u you are not setting the upstream branch and the next push will fail
    • git push --set-upstream origin main

Pull code

  • git pull: download code and information
  • git fetch: download only information

Hooks folder

Managing action triggers before after push or commit ecc.

Workflow

Github Actions

  • on push
  • live testing on github servers or locally

GitOps

The creation of servers both in the cloud or on premise, is pushed via Terraform or Ansible configurations

  • manifests
  • playbooks

The previous workflow is applied to these configurations therefore they are testes, rewied before the get applied in any environment.

There are two types of deployment

Push: pushing from the pipeline to the deployment servers Pull: pulling from the agent installed into the deployment servers to the repository

  • desired state
  • actual state

Flux and Argo

DevOps flow