Terraform Fundamentals: Community

Terraform’s Community Provider: Bridging the Gap Between Open Source and Infrastructure

The relentless pace of cloud service evolution often leaves Terraform users scrambling to keep up. New services emerge, existing ones change APIs, and the official Terraform providers lag. This creates a significant challenge for organizations striving for automated, repeatable infrastructure. We need a way to integrate with these rapidly changing ecosystems without waiting for official provider support or resorting to brittle custom scripting. Terraform’s “Community” provider, specifically the hashicorp/community provider, addresses this gap, offering access to a growing collection of resources for services lacking official support. It’s a critical component in modern IaC pipelines, particularly within platform engineering teams building self-service infrastructure.

What is the hashicorp/community Provider?

The hashicorp/community provider isn’t a provider for a specific service; it’s a meta-provider designed to host resources contributed by the Terraform community. It’s a mechanism for delivering functionality before it’s officially adopted into a dedicated provider. Resources within this provider are generally considered experimental or in active development, so stability and long-term support aren’t guaranteed.

The provider is available on the Terraform Registry: https://registry.terraform.io/providers/hashicorp/community/latest.

Terraform-specific behavior is largely dictated by the individual resource within the provider. Lifecycle management is standard Terraform, but users must be aware of the potential for breaking changes with each provider update. Careful version pinning is crucial.

Use Cases and When to Use

The community provider shines in specific scenarios:

1. Early Access to New Services: When a new cloud service launches without an official Terraform provider, the community provider often provides a rapid path to integration. This allows teams to begin automating infrastructure for these services immediately.
2. Niche or Specialized Integrations: Many smaller or specialized services won’t ever receive official provider support due to limited demand. The community provider offers a viable solution for automating these integrations.
3. Rapid Prototyping: For proof-of-concept projects, the community provider allows quick experimentation with new services without the overhead of building custom solutions.
4. Bridging Gaps in Official Providers: Sometimes, official providers lack specific functionality. Community contributions can fill these gaps, providing a more complete automation experience.
5. Internal Tooling Integration: Teams can contribute resources for their internal tools and services, enabling self-service infrastructure provisioning.

Key Terraform Resources

Here are some examples of resources available within the hashicorp/community provider (as of late 2023/early 2024 – availability changes frequently):

1. community_aws_lambda_layer_version: Manages AWS Lambda Layer Versions.

   resource "community_aws_lambda_layer_version" "example" {
     compatible_runtimes = ["python3.9", "python3.10"]
     description         = "My custom layer"
     path                = "${path.module}/layer"
     name                = "my-layer"
   }

1. community_datadog_integration: Manages Datadog Integrations.

   resource "community_datadog_integration" "example" {
     name = "HTTP Check"
     type = "http-check"
     config = {
       url = "https://example.com"
     }
   }

1. community_google_cloud_run_v2_service: Manages Google Cloud Run v2 Services.

   resource "community_google_cloud_run_v2_service" "default" {
     name     = "my-cloud-run-service"
     location = "us-central1"
     template {
       containers {
         image = "gcr.io/cloudrun/hello"
       }
     }
   }

1. community_github_repository: Manages GitHub repositories.

   resource "community_github_repository" "example" {
     name             = "my-new-repo"
     description      = "A test repository"
     private          = false
     visibility       = "public"
     auto_init        = true
   }

1. community_pagerduty_escalation_policy: Manages PagerDuty Escalation Policies.

   resource "community_pagerduty_escalation_policy" "example" {
     name        = "My Escalation Policy"
     summary     = "A test policy"
     escalation_rules = [
       {
         steps = [
           {
             users = ["[e-mail]"]
           }
         ]
       }
     ]
   }

1. community_vault_secret_engine_mount: Manages Vault Secret Engines.

   resource "community_vault_secret_engine_mount" "example" {
     path = "kv"
     type = "kv"
   }

1. community_akamai_edge_hostname: Manages Akamai Edge Hostnames.

   resource "community_akamai_edge_hostname" "example" {
     hostname = "www.example.com"
     edge_hostname_id = 12345
   }

1. community_azuread_application: Manages Azure Active Directory Applications.

   resource "community_azuread_application" "example" {
     display_name = "My Application"
     reply_urls = ["https://example.com"]
   }

Dependencies are resource-specific. Lifecycle rules should be carefully considered, especially when dealing with experimental resources. Ordering is managed through Terraform’s dependency graph. Limitations are documented within each resource’s documentation on the Terraform Registry.

Common Patterns & Modules

Using the community provider effectively requires careful planning.

• Remote Backends: Always use a remote backend (e.g., Terraform Cloud, S3) to manage state, especially with potentially unstable resources.
• Dynamic Blocks: Many community resources require dynamic blocks to handle complex configurations.
• for_each: Utilize for_each to create multiple instances of a resource based on a map or list.
• Monorepo Structure: A monorepo allows for centralized management of all infrastructure code, including modules utilizing the community provider.
• Layered Architecture: Separate core infrastructure from application-specific configurations. The community provider resources can be encapsulated within application-specific modules.

Public modules are less common for community resources due to their experimental nature. However, searching the Terraform Registry can reveal community-contributed modules.

Hands-On Tutorial: Deploying a Datadog Monitor

Let's deploy a simple Datadog HTTP check using the community provider.

terraform {
  required_providers {
    community = {
      source  = "hashicorp/community"
      version = "~> 23.12" # Pin to a specific version!

    }
  }
}

provider "community" {
  datadog {
    api_key = var.datadog_api_key
    app_key = var.datadog_app_key
  }
}

variable "datadog_api_key" {
  type = string
  sensitive = true
}

variable "datadog_app_key" {
  type = string
  sensitive = true
}

resource "community_datadog_integration" "http_check" {
  name = "My HTTP Check"
  type = "http-check"
  config = {
    url = "https://www.example.com"
  }
}

output "integration_id" {
  value = community_datadog_integration.http_check.id
}

Apply & Destroy:

terraform init
terraform plan -var="datadog_api_key=YOUR_API_KEY" -var="datadog_app_key=YOUR_APP_KEY"
terraform apply -var="datadog_api_key=YOUR_API_KEY" -var="datadog_app_key=YOUR_APP_KEY"
terraform destroy -var="datadog_api_key=YOUR_API_KEY" -var="datadog_app_key=YOUR_APP_KEY"

This example demonstrates a basic integration. In a CI/CD pipeline, this code would be executed as part of an automated deployment process.

Enterprise Considerations

Large organizations should treat the community provider with caution.

• Terraform Cloud/Enterprise: Utilize remote runs and version control integration for auditability and collaboration.
• Sentinel/Policy-as-Code: Implement strict policies to control the use of community resources, limiting which resources can be deployed and enforcing tagging standards.
• IAM Design: Apply the principle of least privilege when configuring credentials for the community provider.
• State Locking: Enable state locking to prevent concurrent modifications.
• Costs: Monitor the costs associated with the services being provisioned through the community provider.
• Scaling: Consider the scalability implications of the services being provisioned.
• Multi-Region: Carefully plan for multi-region deployments, ensuring that the community resources are deployed consistently across all regions.

Security and Compliance

Security is paramount.

resource "aws_iam_policy" "datadog_policy" {
  name        = "datadog-policy"
  description = "Policy for Datadog integration"
  policy      = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = [
          "datadog:*"
        ]
        Effect   = "Allow"
        Resource = "*"
      }
    ]
  })
}

Enforce least privilege by granting only the necessary permissions. Implement drift detection to identify unauthorized changes. Tag all resources for cost allocation and accountability. Audit all changes to the infrastructure.

Integration with Other Services

Here's a diagram illustrating integration with other services:

graph LR
    A[Terraform] --> B(Community Provider);
    B --> C{Datadog};
    B --> D{AWS};
    B --> E{Azure};
    B --> F{Google Cloud};
    B --> G{PagerDuty};

The community provider acts as a bridge, enabling Terraform to interact with services that lack official provider support. For example, integrating with Datadog for monitoring, AWS for compute, Azure for identity, Google Cloud for serverless functions, and PagerDuty for incident management.

Module Design Best Practices

Abstract community resources into reusable modules.

• Input/Output Variables: Define clear input variables for customization and output variables for referencing resource attributes.
• Locals: Use locals to simplify complex configurations.
• Backends: Utilize remote backends for state management.
• Documentation: Provide comprehensive documentation for each module, including usage examples and limitations.

CI/CD Automation

# .github/workflows/deploy.yml

name: Deploy Infrastructure

on:
  push:
    branches:
      - main

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: hashicorp/setup-terraform@v2
      - run: terraform fmt
      - run: terraform validate
      - run: terraform plan -var="datadog_api_key=${{ secrets.DATADOG_API_KEY }}" -var="datadog_app_key=${{ secrets.DATADOG_APP_KEY }}"
      - run: terraform apply -auto-approve -var="datadog_api_key=${{ secrets.DATADOG_API_KEY }}" -var="datadog_app_key=${{ secrets.DATADOG_APP_KEY }}"

This GitHub Actions workflow automates the deployment process, including formatting, validation, planning, and applying the Terraform configuration.

Pitfalls & Troubleshooting

1. Breaking Changes: community resources are prone to breaking changes. Pin versions aggressively.
2. Lack of Documentation: Documentation can be sparse. Consult the resource’s source code and community forums.
3. API Differences: The community provider may not fully replicate the official API of the underlying service.
4. State Corruption: Due to instability, state corruption is a risk. Regular backups are essential.
5. Authentication Issues: Incorrectly configured credentials can lead to authentication failures.
6. Resource Conflicts: Conflicts can arise when multiple Terraform runs attempt to modify the same resources concurrently.

Pros and Cons

Pros:

• Rapid integration with new services.
• Access to niche or specialized integrations.
• Community-driven development.
• Flexibility and customization.

Cons:

• Instability and potential for breaking changes.
• Limited documentation and support.
• Security risks if not carefully managed.
• Requires ongoing maintenance and monitoring.

Conclusion

The hashicorp/community provider is a powerful tool for bridging the gap between the rapidly evolving cloud landscape and Terraform’s infrastructure-as-code capabilities. It’s not a replacement for official providers, but a valuable supplement for organizations that need to integrate with services lacking official support. Engineers should approach it with caution, prioritizing version pinning, robust testing, and strict policy enforcement. Start with a proof-of-concept, evaluate community-contributed modules, and integrate it into your CI/CD pipeline to unlock its full potential.