Understanding github.event.inputs in GitHub Actions

When working with GitHub Actions, you often want your workflows to be flexible rather than hard-coded. One powerful way to achieve this is by using custom inputs with the workflow_dispatch event.

The github.event.inputs context allows you to access values that are provided manually at the time of triggering a workflow. This makes your automation dynamic and reusable across different scenarios.

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🔹 What is workflow_dispatch?

workflow_dispatch is a trigger that lets you manually run a workflow from the GitHub UI. While triggering it, you can pass custom input values, which can then be used inside the workflow.

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🔹 Why use github.event.inputs?

Instead of hardcoding values like environment names or version numbers, you can:

• Provide inputs at runtime
• Make workflows reusable
• Reduce duplication
• Improve control over deployments and scripts

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🔹 Example 1: Basic Input Usage

This example demonstrates how to define a simple input and print it during workflow execution.

on:
  workflow_dispatch:
    inputs:
      logLevel:
        description: 'Log level'
        required: true
        default: 'warning'

jobs:
  print-log:
    runs-on: ubuntu-latest
    steps:
      - name: Print the input
        run: echo "The log level is ${{ github.event.inputs.logLevel }}"

✅ What happens here?

• A user manually triggers the workflow
• They can enter a value for logLevel (or use the default)
• The workflow prints the selected value

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🔹 Example 2: Advanced Inputs with Choices

You can also define more structured inputs, such as dropdowns and optional parameters.

1. Defining Inputs

on:
  workflow_dispatch:
    inputs:
      environment:
        description: 'Target environment'
        required: true
        default: 'development'
        type: choice
        options:
          - development
          - staging
          - production
      db_patch_version:
        description: 'Version number for the patch'
        required: false
        type: string

2. Accessing Inputs in Workflow

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - name: Run Migration
        run: |
          echo "Deploying to: ${{ github.event.inputs.environment }}"
          echo "Applying patch: ${{ github.event.inputs.db_patch_version }}"

✅ What happens here?

• The user selects an environment from a dropdown
• Optionally provides a database patch version
• The workflow uses these inputs during execution

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🔹 Key Takeaways

• github.event.inputs is used to access user-provided values in manually triggered workflows
• Inputs must be defined under on: workflow_dispatch

• Values are accessed using:

  ${{ github.event.inputs.<input_name> }}
  

• Supports multiple types like:
  • string
  • choice (dropdown)
  • boolean (in newer versions)