Patch Env Files

Patches environment files (.env) with configuration values from JSON, supporting both single and multiple file updates.

Features

• 🔧 Flexible patching - Update one or multiple .env files in a single action
• 📝 Base64 support - Handles encoded JSON patches
• 🎯 Precise updates - Add new or override existing environment variables
• 📁 Auto-create - Creates files and directories as needed
• 🔄 Idempotent - Safe to run multiple times

Usage

Single file patching

- name: Patch .env file
  uses: KoalaOps/patch-env-files@v1
  with:
    patches: |
      {
        ".env": {
          "API_KEY": "${{ secrets.API_KEY }}",
          "DEBUG": "true"
        }
      }

Multiple files patching

- name: Patch multiple env files
  uses: KoalaOps/patch-env-files@v1
  with:
    patches: |
      {
        ".env": {
          "APP_ENV": "production"
        },
        "backend/.env": {
          "DATABASE_URL": "${{ secrets.DB_URL }}",
          "PORT": "3000"
        },
        "frontend/.env": {
          "REACT_APP_API_URL": "https://api.example.com"
        }
      }

With base64 encoded patches

- name: Patch with base64 config
  uses: KoalaOps/patch-env-files@v1
  with:
    patches: ${{ secrets.ENV_PATCHES_B64 }}

Inputs

Input	Description	Required	Default
path	Working directory path	❌	'.'
patches	JSON object mapping file paths to key-value pairs (can be base64 encoded)	✅	-

Outputs

Output	Description
updated_files	Comma-separated list of updated files

Patches Format

JSON object mapping file paths to their key-value patches:

{
  ".env": {
    "API_URL": "https://api.production.example.com",
    "LOG_LEVEL": "info"
  },
  "backend/.env": {
    "DATABASE_URL": "postgresql://...",
    "REDIS_URL": "redis://..."
  }
}

Examples

Dynamic version injection

- name: Inject build metadata
  uses: KoalaOps/patch-env-files@v1
  with:
    patches: |
      {
        ".env": {
          "VERSION": "${{ github.sha }}",
          "BUILD_TIME": "${{ github.event.head_commit.timestamp }}",
          "DEPLOYED_BY": "${{ github.actor }}"
        }
      }

Environment-specific configuration

- name: Apply environment config
  uses: KoalaOps/patch-env-files@v1
  with:
    path: ./deploy
    patches: |
      {
        "production/.env": {
          "LOG_LEVEL": "error",
          "CACHE_TTL": "3600"
        },
        "staging/.env": {
          "LOG_LEVEL": "debug",
          "CACHE_TTL": "60"
        }
      }

Conditional patching

- name: Apply runtime overrides if provided
  if: inputs.runtime_patches_b64 != ''
  uses: KoalaOps/patch-env-files@v1
  with:
    patches: ${{ inputs.runtime_patches_b64 }}

How It Works

1. Decodes base64 patches (if encoded)
2. Validates JSON structure
3. For each file in the patches object:
   • Creates the file if it doesn't exist
   • Creates parent directories if needed
   • Updates existing keys or adds new ones
   • Preserves other keys in the file

Notes

• Supports both base64 encoded and plain JSON patches
• Files and directories are created automatically if they don't exist
• Existing keys are updated in place, preserving file structure
• Safe to run multiple times (idempotent operation)
• No external dependencies required