Talk given at Git merge 2018 introducing Game of Dev Life.

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Simulating Git Workflows
Make informed decisions

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Johan Abildskov @RandomSort
● Trainer
● Continuous Delivery Consultant
● Git, Jenkins, Gradle, Artifactory ...

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● Continuous Delivery
● We’ve migrated a lot of companies to a Git toolchain
● Try to help people become better at delivering software
● Also by teaching the next generation

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What brought me here?

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Music on Cuba

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Continuous Delivery Consultant
I help (primarily embedded) software companies get
better at delivering software.
This includes teaching, consulting, tool development
and a whole lot of arguing.

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● We can’t do this here
● NIH-syndrome
● Why should I learn Git? I’m just a software developer
The consultants challenges

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● Seeing diverse environments
● Helping people get many “Oh” or “That’s clever”
● Providing people with the opportunity to shine
The consultants rewards

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● Taught Git on two continents
● Open-sourced the Git katas
● I do consulting, so I spent a lot of time discussing Git
But I try..

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So you are on Git..

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● Git flow
● Github Flow
● Pull Requests?
● Automation?
● Simplified Git Workflow
● The Git Development Git flow?!?
Research online

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The reality
SVN WAS
BETTER!

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ClearCase is very different from Git
Git allows you to work in new ways, to not force you to work a specific way
Own it!
We’re used to working this way
This is our workflow. Now
make it run in Git!

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Centralized workflow
● Commit to master
● Push to master
● Pros: Simple few commands
● Cons: Easy to interfere with other developers
● Hard to protect the integrity of the master branch
● “You broke my build!” Or even worse “Who broke my build?”

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The Git Flow

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Pull request

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Git Phlow
Master
ready/iss53
Master

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The Git Core Development Git Flow

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Git Workflow Dichotomy

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I like Numbers

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25. @randomsortSource: https://www.atlassian.com/git/articles/10-years-of-git

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DORA says trunk based development
https://puppet.com/resources/whitepaper/state-of-devops-report

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Scientific Method(?)
● A
● B

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Graph of stuff over time
VALUE
TIME

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• Continuous Delivery
• DevOps
• Agile
• Scrum
The buzzwords that drive us

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● 1 developer
● No commits
● No deliveries
● How does that look like
Scenario 0:

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Overview of Game of Developer Life

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Diagrams and stuff ...

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This is Diagram
Game Over?
Game Start
Actors Act State updates

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● Developers develop
● Game state is reported
● We evaluate if our game should end
Overview of a turn

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● Developers
● Future could include robots
○ CI/CD server, etc.
● Strategies for:
○ Working
○ (Unintentionally) Introducing Bugs
○ Committing
○ Delivering
○ Fixing bugs
Actors

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● Holds work/value
● Can have a push strategy
Repositories

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This is not the real world, but ...

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● 1 developer
● Commits value at some frequency
● Never delivers
Scenario 1

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Building Inventory

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● We have 1 developer
● The developer commits and delivers value at some frequency
● What effect has altering those frequencies
Scenario 3

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● Having something in production is better than not having something in
production
So let’s look at the cumulative value

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● We have N developers
● The cost of a merge conflict is x
● The probability of a merge conflict is somehow connected to the
amount of work being merge
● What happens if we vary these parameters
Scenario 4

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Thank you @figaw

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● It’s not about the workflow
● It’s how you work with the workflow
● The right workflow will not fix your broken culture
Conclusions

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● Represent tasks?
● Represent automation?
● Context switching?
Future work

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• https://github.com/randomsort/gameofdevlife
• Gather weights from your own organization and try stuff out
Do your own experiments

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http://opinionatedgit.com
● Twitter/GitHub: RandomSort
● github.com/praqma-training/gitkatas
● github.com/randomsort/gameofdevlife
Please tell me why I’m wrong

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● Slides and code will be available on Twitter #gitmerge
Questions?