Terraform Enterprise FDO Helm Chart - mapping values are not allowed in this context

Problem

When deploying Terraform Enterprise using the Flexible Deployment Options Helm chart, you may encounter an error indicating a YAML parsing failure if the chart values are improperly formatted.

Error: YAML parse error on terraform-enterprise/templates/filename.yaml: error converting YAML to JSON: yaml: line ##: mapping values are not allowed in this context

Cause

Helm is a templating engine that generates Kubernetes manifests using data from your values.yaml file. If there is a syntax error in your values.yaml file, it can introduce invalid YAML into the final rendered manifest, causing the deployment to fail. The file name and line number in the error message refer to the final templated output, not your original values.yaml file, which can make debugging difficult.

Solutions

Solution 1: Render and Inspect the Helm Chart Locally

To identify the syntax error, you can render the chart templates locally. This allows you to inspect the generated Kubernetes manifest and find the source of the invalid YAML.

1. Add the HashiCorp Helm repository if you have not already.

   $ helm repo add hashicorp https://helm.releases.hashicorp.com

2. Update your local Helm repository information to ensure you have the latest chart versions.

   $ helm repo update

3. Render the chart templates locally using the helm template command. This command generates the final manifests in a specified directory without deploying them.

   The --debug flag is important because it allows the template process to complete even if the resulting YAML is invalid.

   $ helm template --output-dir out --debug <release_name> hashicorp/terraform-enterprise -f values.yaml

4. Inspect the generated manifest file. Navigate to the out/ directory and open the file name referenced in the original error message. Examine the line number from the error to identify the invalid syntax. Some code editors will highlight YAML errors automatically.
5. Cross-reference the invalid section with the official Terraform Enterprise Helm chart templates and your values.yaml file to understand how your values produced the incorrect output and make the necessary corrections.

Additional Information

• Terraform Enterprise Helm Chart GitHub Repository
• Helm Template Command Documentation
• Helm Cheatsheet