GitHub Actions basics - Step-by-Step Execution

Process Flow - GitHub Actions basics

Push code to GitHub

↓

GitHub detects push event

↓

Trigger GitHub Actions workflow

↓

Run defined jobs and steps

↓

Jobs execute commands (build, test, deploy)

↓

Workflow completes with success or failure

↓

Status shown on GitHub repository

This flow shows how pushing code to GitHub triggers a workflow that runs jobs and steps, then reports the result.

Execution Sample

Git

name: CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: echo "Hello from GitHub Actions!"

This workflow runs on every push and prints a message in the job.

Process Table

Step	Action	Evaluation	Result
1	Push code to GitHub	Event detected	Workflow triggered
2	Start job 'build'	Runs on ubuntu-latest	Job environment ready
3	Run step: echo message	Execute shell command	Output: Hello from GitHub Actions!
4	Job completes	No errors	Job success
5	Workflow completes	All jobs done	Workflow success status shown

💡 Workflow ends after all jobs and steps finish successfully.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
Workflow status	Not started	Triggered	Running	Running	Success
Job status	Not started	Not started	Running	Success	Success
Step output	None	None	None	Hello from GitHub Actions!	Hello from GitHub Actions!

Key Moments - 3 Insights

Why does the workflow start when I push code?

Because the workflow is set to trigger on the 'push' event, as shown in execution_table step 1.

What does 'runs-on: ubuntu-latest' mean?

It means the job runs on a fresh Ubuntu virtual machine provided by GitHub, as seen in step 2.

How do I know if my command ran successfully?

The command output appears in step 3, and the job success in step 4 confirms no errors.

Visual Quiz - 3 Questions

Look at the execution table, what is the workflow status after step 2?

A Running

B Success

C Not started

D Failed

💡 Hint

Check the 'Workflow status' row in variable_tracker after Step 2.

At which step does the job environment become ready?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Action' and 'Result' columns in execution_table for job start.

If the echo command failed, what would change in the execution table?

A Step 1 would not trigger the workflow

B Step 2 would not run the job

C Step 3 would show an error output and Step 4 would show failure

D Step 5 would show success anyway

💡 Hint

Refer to step 3 and 4 in execution_table for command execution and job completion.

Concept Snapshot

GitHub Actions basics:
- Trigger workflows on events like push
- Define jobs with 'runs-on' to set environment
- Jobs have steps that run commands
- Workflow status shows success or failure
- Outputs appear in job logs

Full Transcript

GitHub Actions basics start when you push code to your GitHub repository. This push event triggers a workflow defined in a YAML file. The workflow runs jobs on virtual machines like 'ubuntu-latest'. Each job runs steps, which are commands like printing messages or running tests. The workflow ends with a success or failure status shown on GitHub. This visual trace shows each step from push to workflow completion, tracking status and outputs clearly.