In this tutorial, you will set up Digger to automate terraform pull requests using Github Actions and AWS

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Prerequisites

Digger GitHub App does not need access to your cloud account, it just starts jobs in your CI. All sensitive data stays in your CI job.

You can also self-host Digger orchestrator with a private GiHub app and issue your own token

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Create Action Secrets with AWS credentials (you can also use OIDC)

In GitHub repository settings, go to Secrets and Variables - Actions. Create the following secrets:

  • AWS_ACCESS_KEY_ID
  • AWS_SECRET_ACCESS_KEY

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Create digger.yml

This file contains Digger configuration and needs to be placed at the root level of your repository. Assuming your terraform code is in the prod directory:

projects:
- name: production
  dir: prod

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Create Github Actions workflow file

Place it at .github/workflows/digger_workflow.yml (name is important!)

name: Digger Workflow

on:
  workflow_dispatch:
    inputs:
      spec:
        required: true
      run_name:
        required: false

run-name: '${{inputs.run_name}}'

jobs:
  digger-job:
    runs-on: ubuntu-latest
    permissions:
      contents: write # required to merge PRs
      actions: write # required for plan persistence
      id-token: write # required for workload-identity-federation
      pull-requests: write # required to post PR comments
      statuses: write # required to validate combined PR status

    steps:
      - uses: actions/checkout@v4
      - name: ${{ fromJSON(github.event.inputs.spec).job_id }}
        run: echo "job id ${{ fromJSON(github.event.inputs.spec).job_id }}"
      - uses: diggerhq/digger@vLatest
        with:
          digger-spec: ${{ inputs.spec }}
          setup-aws: true
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

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Create a PR to verify that it works

Terraform will run an existing plan against your code.

Make any change to your terraform code e.g. add a blank line. An action run should start (you can see log output in Actions). After some time you should see output of Terraform Plan added as a comment to your PR.

Then you can add a comment like digger apply and shortly after apply output will be added as comment too.