Infracost Integration

Overmind's Infracost integration provides real-time cost analysis of your infrastructure changes through our GitHub Action. By analyzing Terraform plans through Infracost's pricing engine, it delivers immediate cost context that helps teams make informed deployment decisions.

What This Integration Provides

The Infracost integration enhances your existing Overmind workflow by:

• Parallel Cost Analysis: Runs cost calculations simultaneously with blast radius analysis
• Custom Signal Generation: Transforms cost changes into quantitative signals with graduated severity
• Financial Risk Context: Shows monetary impact alongside technical risks in PR comments
• Threshold-Based Alerting: Configurable cost thresholds trigger warnings before deployment

How Cost Signals Work

Unlike binary policy checks that simply pass or fail, cost signals provide quantitative feedback based on the magnitude of financial change. Each cost modification receives a severity score from -4 to +3:

Severity Scale

Change Type	Severity	Signal Description
>100% increase	-4	Critical cost increase
50-100% increase	-3	High cost increase
20-50% increase	-2	Moderate cost increase
5-20% increase	-1	Minor cost increase
5% change	-	No signal (below threshold)
5-20% decrease	+1	Minor cost reduction
20-50% decrease	+2	Moderate cost reduction
>50% decrease	+3	Significant cost reduction

Changes under 5% are considered normal variation and don't generate signals, keeping your analysis focused on meaningful cost impacts.

Installation

Prerequisites

Before setting up the integration, ensure you have:

• An Overmind account (free signup available)
• Overmind API key stored as OVM_API_KEY in GitHub secrets
• Infracost API key stored as INFRACOST_API_KEY (free at infracost.io)
• Terraform repository with infrastructure code
• GitHub Pull Request workflow (Custom Signals link to PRs)

Basic Setup

Add the cost analysis action to your GitHub workflow:

name: Terraform with Cost Analysis
on:
  pull_request:
    types: [opened, synchronize, reopened]

jobs:
  # Your existing terraform analysis continues unchanged
  terraform:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: overmindtech/actions/install-cli@main
      - uses: overmindtech/actions/submit-plan@main
        with:
          ovm-api-key: ${{ secrets.OVM_API_KEY }}
          plan-json: ./tfplan.json

  # Add parallel cost analysis
  cost-analysis:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3

      - name: Generate Terraform Plan
        run: |
          terraform init
          terraform plan -out=tfplan
          terraform show -json tfplan > tfplan.json

      - uses: overmindtech/cost-signals-action@v1
        with:
          overmind-api-key: ${{ secrets.OVM_API_KEY }}
          infracost-api-key: ${{ secrets.INFRACOST_API_KEY }}
          terraform-plan-json: ./tfplan.json

This setup runs cost analysis in parallel with your existing Overmind terraform analysis, providing financial context without slowing down your workflow.

Configuration Options

Input Parameters

Parameter	Description	Required	Default
overmind-api-key	Your Overmind API key	Yes	-
infracost-api-key	Your Infracost API key	No	-
terraform-plan-json	Path to terraform plan JSON	No	Auto-detected
threshold-percentage	Percentage change to trigger warnings	No	20
threshold-absolute	Absolute dollar change to trigger warnings	No	500
currency	Currency for display (USD, EUR, GBP)	No	USD
submit-on-decreases	Submit signals for cost decreases	No	true
fail-on-threshold	Fail if cost exceeds thresholds	No	false

Advanced Configuration

For teams with specific cost management needs:

- uses: overmindtech/cost-signals-action@v1
  with:
    overmind-api-key: ${{ secrets.OVM_API_KEY }}
    infracost-api-key: ${{ secrets.INFRACOST_API_KEY }}
    terraform-plan-json: './infrastructure/tfplan.json'
    threshold-percentage: 10    # More sensitive to changes
    threshold-absolute: 100     # Lower dollar threshold
    submit-on-decreases: false  # Only track increases
    fail-on-threshold: true     # Block PR on excessive cost
    currency: EUR               # European currency display

Workflow Integration

Analysis Process

When a pull request is created or updated:

1. Parallel Execution: Cost analysis starts immediately alongside terraform analysis
2. Infracost Processing: Terraform plan gets analyzed for resource pricing changes
3. Signal Generation: Cost deltas become Custom Signals with calculated severity
4. Overmind Aggregation: Cost signals combine with blast radius and risk data
5. PR Updates: Comments show financial impact with technical context

PR Comment Enhancement

The integration enriches PR comments with cost information:

## Overmind Analysis

**Cost Changes:** +$142.50/month (+15% increase)
- EC2 instances: +$85.20/month
- RDS storage: +$57.30/month

**Signals:** 3 signals detected
- Cost: Moderate cost increase (-2)
- Policy: No violations detected
- Routine: Following established patterns (+1)

[View detailed analysis →](https://app.overmind.tech/changes/...)

Testing and Validation

Local Testing

Test cost analysis locally without API submission:

# Generate terraform plan
terraform plan -out=tfplan
terraform show -json tfplan > tfplan.json

# Run Infracost analysis
infracost breakdown --path tfplan.json
infracost diff --path tfplan.json

Integration Testing

Test the complete workflow in a pull request environment:

# Set up environment variables
export OVERMIND_API_KEY="your_api_key"
export INFRACOST_API_KEY="your_infracost_key"

# Run action locally using act
act -j cost-analysis --secret-file .env

Troubleshooting

Common Issues

Missing Cost Analysis:

• Verify Infracost API key is correctly configured
• Check that terraform plan JSON contains resource changes
• Ensure plan file path matches configuration

Unexpected Cost Calculations:

• Review Infracost pricing database coverage for your resources
• Check currency settings match your expectations
• Validate terraform plan includes all necessary resource details

Signal Submission Failures:

• Confirm Overmind API key has required permissions
• Verify pull request context is available
• Check network connectivity to Overmind services

Debugging Steps

1. Validate Infracost Setup:

   infracost --version
   infracost auth status

2. Test Plan Analysis:

   infracost breakdown --path tfplan.json --format json

3. Check Action Logs: Review GitHub Actions logs for specific error messages and API responses

Best Practices

Threshold Configuration

• Start Conservative: Begin with default thresholds and adjust based on team feedback
• Environment-Specific: Use different thresholds for development vs production
• Team Alignment: Ensure threshold settings match cost management policies

Workflow Design

• Parallel Processing: Keep cost analysis separate from terraform analysis for speed
• Non-Blocking Default: Use informational signals rather than blocking PRs initially
• Gradual Rollout: Start with tracking-only mode before enabling failure conditions

Cost Management Integration

• Regular Review: Periodically assess threshold effectiveness
• Budget Alignment: Coordinate thresholds with overall infrastructure budgets
• Optimization Tracking: Use positive signals to measure cost reduction initiatives

Support and Resources

• Issues: GitHub Repository
• Infracost Resources: Infracost Documentation

For additional questions about configuration or integration, join our community or contact support through the application interface.