DevOps Classroom Series – 15/Sept/2020

Basic Images

Version Control Systems

• Developers cannot work in Isolation, The code developed by one developer will be used by other Developers
• Now lets explore some options to implement this
  • Network File Share:
    1. Can two people access the file simultaneously and make changes?
    2. Versioning for files is not supported directly
• To resolve these issue A Version Control System was created. Version Control System should have versions of changes made.
• During the course of 40 years, we have 3 major generations of version control systems

Generation-1 Version Control System

• Examples: RCS, SCCS
• Networking: Not supported
• Operations: One file at time
• Concurrency: Locks

Generation-2 Version Control Systems (Centralized)

• Examples: CVS, Visual Source Safe, Clear Case, Subversion etc..
• Networking: Centralized
• Operations: Multi-file
• Concurrency: yes
• In Generation we have two major models
  • Clients should always be connected to servers
  • Clients can work offline and connect to server before submitting changes
• All the code gets stored and versioned on the server.
• As the sites increase the administrative efforts increase and admins need to set up Disaster Recovery and Backups. Maintain sync between sites (VCS-Server)

Generation-3: Version Control Systems (Distributed)

• Examples: Git, Mercurial
• Operations: Changesets (Multi files)
• Network: Distributed
• GIT (global information tracker) was built by linus torvalds and he implemented a simple, clean distributed vcs.

Version Control System:

• This is a system that records changes to files, maintains history which we call as versions or revisions and It will help multiple users to connect to it & create, update, retrieve and delete the changes

Git:

• Git is a open-source and free software Refer Here.
• In Git We have two major use cases
  • Client Software:
    • Git
    • GitBash
    • Source Tree
    • Tortoise Git
    • Git has extensions in almost all IDEs.
  • Server features on Git (Connectivity to clients, User Management)
    • Gitolite (On-premise)
    • GitHub
    • GitLab
    • BitBucket
    • CodeCommit
    • Azure Source Repo’s