How-to enable "hairpin_addressing" in Terraform Enterprise FDO Podman

Expected Outcome

After completing this procedure, the Terraform Enterprise container will have a host mapping that resolves its own hostname to the private IP address of the instance, enabling hairpin addressing.

Prerequisites

• An existing Terraform Enterprise installation using Flexible Deployment Options with Podman.

Use Case

This procedure is for users who are migrating from a Replicated installation to Flexible Deployment Options and need to enable the equivalent of hairpin_addressing for the main Terraform Enterprise application container.

Procedure

1. Edit the Kubernetes YAML file for your Terraform Enterprise Pod and add a hostAliases block under the Pod spec. This block maps the TFE hostname to the private IP address of the node.

2. ---
   apiVersion: "v1"
   kind: "Pod"
   ...
   spec:
     hostAliases:
     - ip: "<private_ip_of_the_node>"
       hostnames: ["<TFE hostname e.g. terraform.example.com>"]

3. Restart the Terraform Enterprise Pod to apply the changes. If you have configured Terraform Enterprise to run as a systemd service, use the standard service commands. Otherwise, restart it manually with podman.

   ## Stop the existing Pod
   # podman kube down <path_to_YAML_file>
   
   ## Start the Pod with the updated configuration
   # podman kube play <path_to_YAML_file>

4. Verify that the host mapping was successfully applied by inspecting the Pod's configuration. The output should show the added hostname and IP address.

   # podman pod inspect terraform-enterprise -f '{{.InfraConfig.HostAdd}}'
   ## Output should be similar to:
   ## [terraform.example.com:10.240.100.10]

5. Alternatively, you can verify the change by checking the container's /etc/hosts file.

Additional Information

To enable hairpin_addressing for Terraform runs executed by agents, you must set the TFE_RUN_PIPELINE_DOCKER_EXTRA_HOSTS environment variable. This setting applies the extra_hosts configuration to the agent containers.

• Manage Podman Service with Systemd
• Docker Driver settings for extra_hosts