Terraform Hiera Backend

This function allows hiera to query data from a Terraform backend. Any backend supported by Terraform can be queried.

Installation

Build the plugin from the root directory of this module:

go build -o terraform_backend

Then make the plugin available to Hiera. See Extending Hiera for info on how to do that.

A Note about debugging

When debugging remotely from an IDE like JetBrains goland, use -gcflags 'all=N -l' to ensure that all symbols are present in the final binary.

go build -o terraform_backend -gcflags 'all=-N -l'

Examples

Example using a local backend:

---
version: 5
defaults:
  datadir: hiera
  data_hash: yaml_data

hierarchy:
- name: common
  path: common.yaml
- name: terraform_backend_local
  data_hash: terraform_backend
  options:
    backend: local
    config:
      path: /tfdir/terraform.tfstate

Example using a remote S3 backend:

---
version: 5
defaults:
  datadir: hiera
  data_hash: yaml_data

hierarchy:
- name: common
  path: common.yaml
- name: terraform_backend_s3
  data_hash: terraform_backend
  options:
    backend: s3
    config:
      bucket: mybucket
      key: path/to/my/key
      region: us-east-1

Example using a root key:

---
version: 5
defaults:
  datadir: hiera
  data_hash: yaml_data

hierarchy:
- name: common
  path: common.yaml
- name: terraform_backend_local
  data_hash: terraform_backend
  root_key: terraform
  options:
    backend: local
    config:
      path: /tfdir/terraform.tfstate

---
some_value: "%{lookup('terraform.some_output')}"

• backend - The name of the backend.

• config - A map of options to configure the backend. See the Terraform documentation for each backend.

• workspace - The name of the workspace. If not set the default workspace will be used.

• root_key - If set then the state outputs will be wrapped in a map with this value as the root key.

If the backend supports reading options from environment variables this will work as well.