https://github.com/dflook/terraform-output

GitHub action to get outputs from a terraform configuration
https://github.com/dflook/terraform-output

actions devops github-action github-actions terraform

Last synced: about 2 months ago
JSON representation

GitHub action to get outputs from a terraform configuration

• Host: GitHub
• URL: https://github.com/dflook/terraform-output
• Owner: dflook
• Created: 2020-07-05T22:53:25.000Z (over 4 years ago)
• Default Branch: main
• Last Pushed: 2024-05-28T19:56:42.000Z (7 months ago)
• Last Synced: 2024-05-29T10:48:01.741Z (7 months ago)
• Topics: actions, devops, github-action, github-actions, terraform
• Homepage:
• Size: 36.1 KB
• Stars: 5
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml

Awesome Lists containing this project

README

        
# terraform-output action

This is one of a suite of Terraform related actions - find them at [dflook/terraform-github-actions](https://github.com/dflook/terraform-github-actions).

Retrieve the root-level outputs from a Terraform configuration.

## Inputs

* `path`

  Path to the Terraform root module

  - Type: string

  - Optional

  - Default: The action workspace

* `workspace`

  Terraform workspace to get outputs from

  - Type: string

  - Optional

  - Default: `default`

* `backend_config`

  List of Terraform backend config values, one per line.

  ```yaml

  with:

    backend_config: token=${{ secrets.BACKEND_TOKEN }}

  ```

  - Type: string

  - Optional

* `backend_config_file`

  List of Terraform backend config files to use, one per line.

  Paths should be relative to the GitHub Actions workspace

  ```yaml

  with:

    backend_config_file: prod.backend.tfvars

  ```

  - Type: string

  - Optional

## Environment Variables

* `GITHUB_DOT_COM_TOKEN`

  This is used to specify a token for GitHub.com when the action is running on a GitHub Enterprise instance.

  This is only used for downloading OpenTofu binaries from GitHub.com.

  If this is not set, an unauthenticated request will be made to GitHub.com to download the binary, which may be rate limited.

  - Type: string

  - Optional

* `TERRAFORM_CLOUD_TOKENS`

  API tokens for cloud hosts, of the form `=`. Multiple tokens may be specified, one per line.

  These tokens may be used with the `remote` backend and for fetching required modules from the registry.

  e.g:

  ```yaml

  env:

    TERRAFORM_CLOUD_TOKENS: app.terraform.io=${{ secrets.TF_CLOUD_TOKEN }}

  ```

  With other registries:

  ```yaml

  env:

    TERRAFORM_CLOUD_TOKENS: |

      app.terraform.io=${{ secrets.TF_CLOUD_TOKEN }}

      terraform.example.com=${{ secrets.TF_REGISTRY_TOKEN }}

  ```

  - Type: string

  - Optional

* `TERRAFORM_SSH_KEY`

  A SSH private key that Terraform will use to fetch git module sources.

  This should be in PEM format.

  For example:

  ```yaml

  env:

    TERRAFORM_SSH_KEY: ${{ secrets.TERRAFORM_SSH_KEY }}

  ```

  - Type: string

  - Optional

* `TERRAFORM_PRE_RUN`

  A set of commands that will be ran prior to `terraform init`. This can be used to customise the environment before running Terraform. 

  

  The runtime environment for these actions is subject to change in minor version releases. If using this environment variable, specify the minor version of the action to use.

  

  The runtime image is currently based on `debian:bullseye`, with the command run using `bash -xeo pipefail`.

  For example:

  ```yaml

  env:

    TERRAFORM_PRE_RUN: |

      # Install latest Azure CLI

      curl -skL https://aka.ms/InstallAzureCLIDeb | bash

      

      # Install postgres client

      apt-get install -y --no-install-recommends postgresql-client

  ```

  - Type: string

  - Optional

* `TERRAFORM_HTTP_CREDENTIALS`

  Credentials that will be used for fetching modules sources with `git::http://`, `git::https://`, `http://` & `https://` schemes.

  Credentials have the format `=:`. Multiple credentials may be specified, one per line.

  Each credential is evaluated in order, and the first matching credentials are used. 

  Credentials that are used by git (`git::http://`, `git::https://`) allow a path after the hostname.

  Paths are ignored by `http://` & `https://` schemes.

  For git module sources, a credential matches if each mentioned path segment is an exact match.

  For example:

  ```yaml

  env:

    TERRAFORM_PRE_RUN: |

      # Install latest Azure CLI

      curl -skL https://aka.ms/InstallAzureCLIDeb | bash

      

      # Install postgres client

      apt-get install -y --no-install-recommends postgresql-client

    TERRAFORM_HTTP_CREDENTIALS: |

      example.com=dflook:${{ secrets.HTTPS_PASSWORD }}

      github.com/dflook/terraform-github-actions.git=dflook-actions:${{ secrets.ACTIONS_PAT }}

      github.com/dflook=dflook:${{ secrets.DFLOOK_PAT }}

      github.com=graham:${{ secrets.GITHUB_PAT }}  

  ```

  - Type: string

  - Optional

## Outputs

An action output will be created for each output of the Terraform configuration.

For example, with the Terraform config:

```hcl

output "service_hostname" {

  value = "example.com"

}

```

Running this action will produce a `service_hostname` output with the value `example.com`.

### Primitive types (string, number, bool)

The values for these types get cast to a string with boolean values being 'true' and 'false'.

### Complex types (list/set/tuple & map/object)

The values for complex types are output as a JSON string. Terraform `list`, `set` & `tuple` types are cast to a JSON array, `map` and `object` types are cast to a JSON object.

These values can be used in a workflow expression by using the [fromJSON](https://docs.github.com/en/actions/reference/context-and-expression-syntax-for-github-actions#fromjson) function

## Example usage

### String

This example uses a Terraform string output to get a hostname:

```yaml

on: [push]

jobs:

  show_hostname:

    runs-on: ubuntu-latest

    name: Show the hostname

    steps:

      - name: Checkout

        uses: actions/checkout@v4

      - name: Get outputs

        uses: dflook/terraform-output@v1

        id: tf-outputs

        with:

          path: my-terraform-config

      - name: Print the hostname

        run: echo "The hostname is ${{ steps.tf-outputs.outputs.hostname }}"

```

### Complex output

This example gets information from object and array(object) outputs.

With this Terraform config:

```hcl

output "vpc" {

  value = aws_vpc.test

}

output "subnets" {

  value = [aws_subnet.a, aws_subnet.b, aws_subnet.c]

}

```

We can use the workflow:

```yaml

jobs:

  output_example:

    runs-on: ubuntu-latest

    name: An example of workflow expressions with terraform output

    steps:

      - name: Checkout

        uses: actions/checkout@v4

      - name: Get outputs

        uses: dflook/terraform-output@v1

        id: tf-outputs

        with:

          path: my-terraform-config

      - name: Print VPC

        run: |

          echo "The vpc-id is ${{ fromJson(steps.tf-outputs.outputs.vpc).id }}"

          echo "The subnet-ids are ${{ join(fromJson(steps.tf-outputs.outputs.subnets).*.id) }}"          

```

Which will print to the workflow log:

```

The vpc-id is vpc-01463b6b84e1454ce

The subnet-ids are subnet-053008016a2c1768c,subnet-07d4ce437c43eba2f,subnet-0a5f8c3a20023b8c0

```