Export Tofu output Gthub Actions composite

Description

This action composite allows to export OpenTofu outputs in json format to GITHUB_OUTPUT using base64 encoding.

The original idea for this was found on https://github.com/orgs/community/discussions/25225#discussioncomment-6776295 discussion and belongs to rdhar.

Inputs

inputs:
  workdir:
    required: true
    description: Tofu working directory

Example usage

This composite always puts all the Tofu outputs together in single tf_outputs GITHUB_OUTPUTS variable. It can be accessed later only if the step has an id attribute.

To use exported outputs in another Tofu job/workflow you can use marcinbator/import-tofu-output@v1.0.0 (https://github.com/marcinbator/import-tofu-output) composite which combines all of exported outputs into one .tfvars.json file that can be used by Tofu (as shown in Full example below).

Make sure every Tofu output has unique name to avoid errors during Tofu execution.

- id: output
  name: Output TF vars
  uses: marcinbator/export-tofu-output@v1.0.0
  with:
    workdir: ${{ env.WORKDIR }}

Full example

jobs:
  rds: # this job exports outputs to GITHUB_OUTPUT using marcinbator/export-tofu-output@v1.0.0. Outputs are always exported to `tf_outputs` output.
    runs-on: ubuntu-latest
    outputs:
      tf_outputs: ${{ steps.output.outputs.tf_outputs }}
    defaults:
      run: working-directory:./rds

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup OpenTofu
        uses: opentofu/setup-opentofu@v1
        with:
          tofu_version: 1.11.2

      - name: TF init
        run: tofu init

      - name: TF Apply
        run: tofu apply -auto-approve -input=false

      - id: output
        name: Output TF vars
        uses: marcinbator/export-tofu-output@v1.0.0 # here
        with:
          workdir: ./rds

  db: # this job uses outputs exported in previous job
    runs-on: ubuntu-latest
    needs: rds
    defaults:
      run:
        working-directory: ./db

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup OpenTofu
        uses: opentofu/setup-opentofu@v1
        with:
          tofu_version: 1.11.2

      - name: Extract TF variables
        uses: marcinbator/import-tofu-output@v1.0.0 # here
        with:
          workdir: ./db
        env:
          rds_outputs: ${{ needs.rds.outputs.tf_outputs }} #outputs needs to be passed in env variable with `_outputs` suffix.

      - name: TF init
        run: tofu init

      - name: TF Apply
        run: tofu apply -auto-approve -input=false