GH Actions, tftest.TerraformTestError: Error decoding plan output: Expecting value: line 1 column 2 (char 1)

Hi, I’ve been unsuccessful in debugging this error. It appears to emanate from the JSON decoder. However, this only occurs when tests are on a GitHub action. Works without error locally.

Stack

  if not output:
        return self.execute_command('plan', *cmd_args).out
      with tempfile.NamedTemporaryFile() as fp:
        fp.close()
      # for tg we need to specify a temp name that is relative for the output to go into each
      # of the .terragrunt-cache, then plan / show would work, otherwise it overwrites each other!
      temp_file = fp.name if len(
          self._tg_ra()) == 0 else os.path.basename(fp.name)
      cmd_args.append('-out={}'.format(temp_file))
      self.execute_command('plan', *cmd_args)
      result = self.execute_command('show', '-no-color', '-json', temp_file)
      try:
        return self._plan_formatter(result.out)
      except json.JSONDecodeError as e:
>       raise TerraformTestError(
            'Error decoding plan output: {}'.format(e))
E       tftest.TerraformTestError: Error decoding plan output: Expecting value: line 1 column 2 (char 1)

Code

@pytest.fixture(scope='session')
def fixtures_dir():
    return os.path.join(os.path.dirname(os.path.abspath(__file__)), 'fixtures')

@pytest.fixture(scope='session')
def terraform_binary():
    return shutil.which('terraform')

@pytest.fixture
def plan(fixtures_dir, terraform_binary):
    tf = tftest.TerraformTest(tfdir=fixtures_dir, binary=terraform_binary, env=envs)
    tf.init()
    return tf.plan(output=True)

GH Action

  terraform-test:
    name: Terraform Unit Test
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v2
        with:
          terraform_version: 1.2

      - name: Setup Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.10'

      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install -r requirements.txt

      - name: Test with pytest
        run: python -m pytest test-module-fsx-lustre-monitoring.py

[ludoo]

Mikael, have a look at this

https://github.com/ludoo/terraform-module-fsx-lustre/runs/8305560078?check_suite_focus=true

[ludoo]

That’s great and thanks for circling back! We should add it to the README!