notes.txt

Exercise: CI/CD pipeline for Django application using GitHub Actions and Visual Studio Code 

- .gitignore file set up 
- initialized app/ directory as local git repository 
- added README.md "echo "# tutorials_workflow_demo" >> README.md"
- pushed local to remote repository 


# Set up GitHub Actions workflow # 
- created workflow YAML file in local repository (can also be created in GitHub online editor)
    - workflow will trigger on push/pull requests
    - can be triggered manually (workslow_dispatch)
    - job key created (must have name), called "build-and-test"
        - can have many jobs in a workflow and, if so, jobs run parallel and in separate runner environments 
    - each job has a runner environment
        - various virtual machines hosted by GitHub (ubuntu, windows, macOS, etc)
    - steps in a job run sequentially, optionally named, and begin with hyphen
        - "run" and "uses" are common steps 
        - cannot have run and uses of the same name
        - "uses" are how we use "actions"
        - actions can be custom made, or can come from GH Actions Marketplace
        - actions cause runner to checkout repository in job's runner environment
            - using to install python 3.9 in exercise 
        - "run" step access shell in runner environment, to run CLI commands (echo and python)
            - can provide multiple commands to "run" key by using piping cmd: " | "
            - upgraded pip, installed python packages for this app, ran migrations, setup initial databse tables
    - ran pytest


# Trigger workflow # 
- commit YML file changes to remote repository 
- create new branch, Propose new file, create pull requests
- pull request is the event the triggers main.yml to run 
- Run all test steps, can see results from running pytest 
- merged pull request, deleted branch, actions tab has merge under workflow runs


# Manually triggering workflow # 
- able to manually trigger due to "workflow_dispatch" event to the "on" key
- in Actions tab, select workflow, click "Run workflow" on main branch 
- new workflow run recorded in Actions tab, can see it was manually triggered 


# Cause test failure #
- pull request for code with bug in it 

- on GH repository, in tutorials/ directory
    - views.py file, commented out "def get(self, request)" function
    - commit changes, create new branch, propose changes
    - create pull request, go to Actions tab, failed run
    - close pull request, deleted branch