dotenv-seeder

A GitHub Action to seed environment variables into a env file by merging an example file with user-provided values in JSON format. Useful for CI/CD pipelines or setting up local environments consistently.

Features

• Flexible – Supports any file name or path, not just regular .env and .env.example
• Clean – Preserves structure, handles empty lines, and quotes values when needed
• Simple – No magic, no complex config — just JSON input and a reliable result

Basic Usage

name: CI Workflow

on: push

jobs:
  main:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v7

      - name: Seed environment variables
        uses: scrlkx/dotenv-seeder@v2
        with:
          example: ".env.example"
          target: ".env"
          variables: |
            {
              "API_KEY": "{{ secrets.API_KEY }}",
              "DEBUG": "true",
              "BASE_URL": "{{ env.BASE_URL }}"
            }

Inputs

Name	Description	Required	Default
mode	Seeding mode — see Modes below	No	copy-example
example	The example file to copy from if the target file does not exist	No	.env.example
target	The environment file to update or create	No	.env
variables	A JSON object containing environment variables to inject	Yes	—

Modes

The mode input controls whether an example file is required to seed the target file.

copy-example (default)

Copies example to target before applying variables. The example file must exist, or the action fails.

with:
  mode: "copy-example" # optional, this is the default
  example: ".env.example"
  target: ".env"
  variables: |
    { "API_KEY": "{{ secrets.API_KEY }}" }

only-create

Writes or updates target directly, without requiring or copying an example file. Use this when there is no .env.example to seed from.

with:
  mode: "only-create"
  target: ".env"
  variables: |
    { "API_KEY": "{{ secrets.API_KEY }}" }

License

GPL-3.0 License - see the LICENSE file for details