New --format Flag for Terraform Output

The atmos terraform output command now supports a --format flag, making it easy to export Terraform outputs in various formats for use in CI/CD workflows, scripts, and configuration files.

The Problem

Previously, extracting multiple Terraform outputs for use in GitHub Actions required repetitive, verbose commands:

- name: Get Terraform outputs
  run: |
    echo "url=$(atmos terraform output app -s preview --skip-init -- -raw url)" >> $GITHUB_OUTPUT
    echo "bucket=$(atmos terraform output app -s preview --skip-init -- -raw bucket)" >> $GITHUB_OUTPUT
    echo "api_key=$(atmos terraform output app -s preview --skip-init -- -raw api_key)" >> $GITHUB_OUTPUT

Each output required a separate command invocation, which was slow and cumbersome.

The Solution

With the new --format flag, you can export all outputs in a single command:

- name: Get Terraform outputs
  run: atmos terraform output app -s preview --skip-init --format=env --output-file=$GITHUB_OUTPUT

Supported Formats

Format	Output Style	Use Case
json	{"key": "value"}	Machine parsing, piping to jq
yaml	key: value	Human-readable, config files
hcl	key = "value"	Terraform locals or tfvars files
env	key=value	GitHub Actions $GITHUB_OUTPUT
dotenv	key='value'	.env files with quoting
bash	export key='value'	Shell sourcing with eval $(...)
csv	key,value	Spreadsheets, data processing
tsv	key<tab>value	Tab-delimited for easy parsing

Examples

GitHub Actions Workflow

Share outputs between steps:

jobs:
  deploy:
    steps:
      - name: Deploy infrastructure
        run: atmos terraform apply app -s preview --auto-approve

      - name: Export outputs
        id: terraform
        run: atmos terraform output app -s preview --skip-init --format=env --output-file=$GITHUB_OUTPUT

      - name: Use outputs
        run: |
          echo "Deployed to: ${{ steps.terraform.outputs.url }}"
          curl ${{ steps.terraform.outputs.url }}/health

Shell Script Integration

Source outputs directly in bash:

# Export outputs as environment variables
eval $(atmos terraform output vpc -s prod --format=bash)

# Now use them
echo "VPC ID: $vpc_id"
aws ec2 describe-subnets --filters "Name=vpc-id,Values=$vpc_id"

# Use --uppercase for standard ENV_VAR naming convention
eval $(atmos terraform output vpc -s prod --format=bash --uppercase)
echo "VPC ID: $VPC_ID"

Flatten Nested Outputs

Use --flatten to expand nested maps and arrays into individual key/value pairs:

# Without --flatten: {"config": {"host": "localhost", "port": 3000}}
# Output: config={"host":"localhost","port":3000}

# With --flatten: expands nested maps
atmos terraform output app -s prod --format=env --flatten
# Output: config_host=localhost
#         config_port=3000

# Arrays are flattened with numeric indices
# Input: {"subnets": [{"id": "subnet-1"}, {"id": "subnet-2"}]}
# Output: subnets_0_id=subnet-1
#         subnets_1_id=subnet-2

# Combine --flatten with --uppercase for standard ENV_VAR naming
eval $(atmos terraform output app -s prod --format=bash --flatten --uppercase)
echo "Config host: $CONFIG_HOST"
echo "Config port: $CONFIG_PORT"

Write to File

Save outputs to a file for later use:

# Save as .env file
atmos terraform output app -s staging --format=dotenv --output-file=.env

# Save as JSON for processing
atmos terraform output app -s staging --format=json --output-file=outputs.json

# Save as HCL for Terraform locals
atmos terraform output vpc -s prod --format=hcl --output-file=vpc_outputs.auto.tfvars

Backward Compatibility

When --format is not specified, the command passes through to native Terraform/OpenTofu, preserving existing behavior. The -json and -raw flags continue to work as before.

Get Started

The --format flag is available now. See the terraform output documentation for more details.