Terraform API Gateway Stage Deployment Issues & Troubleshooting

• Introduction
• Step-by-Step Guide
• Code Example
• Additional Notes
• Summary
• Conclusion
• References

Managing API Gateway deployments in Terraform can be tricky due to the way deployments and stages interact. While a deployment represents a snapshot of your API configuration, a stage is what makes your API accessible to users. The challenge arises because Terraform might not always detect changes that necessitate a new deployment. To address this, you can use explicit triggers within your aws_api_gateway_deployment resource. This involves creating a hash of relevant resources, such as integrations, and using it in the triggers block. Any modification to these resources alters the hash, prompting Terraform to generate a new deployment. Alternatively, you can employ the create_before_destroy lifecycle rule, although this method might not be as reliable in detecting all changes. When using triggers, ensure you're hashing the appropriate resources. Additionally, always set up your aws_api_gateway_stage resource to depend on the aws_api_gateway_deployment resource, guaranteeing that your stage consistently points to the most recent deployment.

To ensure your API Gateway deployments are updated correctly in Terraform, you need to understand how deployments and stages work together. Here's a breakdown:

1. API Gateway Deployments: A deployment is a snapshot of your API Gateway configuration at a specific point in time. This includes routes, integrations, authorizers, and other settings.
2. API Gateway Stages: A stage is a logical reference to a deployment. It's what you use to expose your API to consumers. You can have multiple stages (e.g., dev, test, prod) pointing to different deployments.

The Problem:

Terraform won't update a deployment if it thinks nothing has changed. This can be problematic because changes to resources like integrations or methods don't always trigger a new deployment.

Solutions:

• Explicitly Trigger Redeployment: The most reliable way to ensure a new deployment is to explicitly tell Terraform to create one whenever relevant resources change. You can achieve this using the triggers block within your aws_api_gateway_deployment resource:

  resource "aws_api_gateway_deployment" "example" {
    rest_api_id = aws_api_gateway_rest_api.example.id
  
    triggers = {
      redeployment = sha1(jsonencode(aws_api_gateway_integration.example))
    }
  }

  In this example, the triggers block uses the sha1 hash of the aws_api_gateway_integration.example resource. Any change to this integration will result in a different hash, triggering a new deployment.

• Lifecycle Configuration (Less Reliable): You can use the create_before_destroy lifecycle rule within your aws_api_gateway_deployment resource. However, this is less reliable as it might not always pick up changes that should trigger a redeployment.

  resource "aws_api_gateway_deployment" "example" {
    # ... other configurations ...
  
    lifecycle {
      create_before_destroy = true
    }
  }

Important Considerations:

• Hashing for Triggers: When using triggers, ensure you're hashing the relevant resources that, when changed, should trigger a new deployment. This could include integrations, methods, authorizers, etc.

• Stage Dependencies: Make sure your aws_api_gateway_stage resource depends on the aws_api_gateway_deployment resource. This ensures the stage always points to the latest deployment.

  resource "aws_api_gateway_stage" "example" {
    # ... other configurations ...
  
    deployment_id = aws_api_gateway_deployment.example.id
  }

By implementing these solutions, you can ensure that your API Gateway deployments are always up-to-date with your Terraform configurations.

This Terraform code defines an API Gateway setup with a REST API, a resource, a method, and an integration. It uses an explicit trigger to redeploy the API whenever the integration configuration changes. This ensures that the API Gateway stage always reflects the latest integration settings. An optional lifecycle configuration for create-before-destroy is shown but commented out. The code also includes a dependency to ensure the stage is created or updated after the deployment. You can customize this code with your API Gateway configurations and apply it using Terraform.

# Configure the AWS Provider
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 4.0"
    }
  }
}

# Configure Variables (Replace with your values)
variable "region" {
  default = "us-east-1"
}

# Create an API Gateway REST API
resource "aws_api_gateway_rest_api" "example" {
  name        = "example"
  description = "Example API Gateway"
}

# Create an API Gateway Resource
resource "aws_api_gateway_resource" "example" {
  rest_api_id = aws_api_gateway_rest_api.example.id
  parent_id   = aws_api_gateway_rest_api.example.root_resource_id
  path_part   = "myresource"
}

# Create an API Gateway Method
resource "aws_api_gateway_method" "example" {
  rest_api_id   = aws_api_gateway_rest_api.example.id
  resource_id   = aws_api_gateway_resource.example.id
  http_method   = "GET"
  authorization = "NONE"
}

# Create an API Gateway Integration
resource "aws_api_gateway_integration" "example" {
  rest_api_id             = aws_api_gateway_rest_api.example.id
  resource_id             = aws_api_gateway_resource.example.id
  http_method             = aws_api_gateway_method.example.http_method
  integration_http_method = "GET"
  type                    = "MOCK"
  request_templates = {
    "application/json" = <<EOF
{
  "statusCode": 200
}
EOF
  }
}

# Create an API Gateway Deployment with Explicit Trigger
resource "aws_api_gateway_deployment" "example" {
  rest_api_id = aws_api_gateway_rest_api.example.id

  triggers = {
    # Trigger redeployment on changes to the integration
    redeployment = sha1(jsonencode(aws_api_gateway_integration.example))
  }

  lifecycle {
    create_before_destroy = true # Optional: Use with caution
  }
}

# Create an API Gateway Stage
resource "aws_api_gateway_stage" "example" {
  deployment_id = aws_api_gateway_deployment.example.id
  rest_api_id   = aws_api_gateway_rest_api.example.id
  stage_name    = "dev"

  depends_on = [aws_api_gateway_deployment.example]
}

Explanation:

1. Resources: The code defines resources for an API Gateway REST API, a resource within the API, a method for the resource, an integration for the method, a deployment, and a stage.
2. Explicit Trigger: The aws_api_gateway_deployment resource includes a triggers block. The redeployment trigger uses the sha1 hash of the aws_api_gateway_integration.example resource. Any change to this integration will modify the hash, triggering a new deployment.
3. Lifecycle Configuration (Optional): The lifecycle block with create_before_destroy is shown but commented out. While it can sometimes trigger redeployments, it's less reliable than explicit triggers.
4. Stage Dependency: The aws_api_gateway_stage resource has a depends_on clause to ensure it's created or updated after the aws_api_gateway_deployment.

How to Use:

1. Replace Placeholder Values: Update the code with your desired API Gateway configurations, such as region, API name, resource paths, and integration details.
2. Apply Terraform: Run terraform apply to create or update your API Gateway infrastructure.

By using this code as a starting point and adapting it to your specific needs, you can ensure that your API Gateway deployments in Terraform are always up-to-date and reflect your desired configuration.

• Idempotency: Terraform strives for idempotency, meaning applying the same configuration multiple times should have the same end state. Explicit triggers help achieve this with API Gateway deployments.
• Drift Detection: Using triggers makes it easier to detect configuration drift. If someone manually changes an integration outside of Terraform, the next terraform plan will show a diff and propose a new deployment to correct the drift.
• Alternative Trigger Sources: Besides hashing resource attributes, you can trigger deployments based on:
  • Versioned Code: Hash the output of a data resource fetching your Lambda function's latest version or S3 object's ETag.
  • External Files: Hash the contents of configuration files that influence your API Gateway setup.
• Deployment Frequency: Be mindful of how often deployments are triggered. Excessive deployments can impact performance and potentially cause service disruptions.
• Blue-Green Deployments: For critical APIs, consider implementing blue-green deployments using multiple stages and traffic shifting for safer updates.
• Monitoring and Rollbacks: Implement monitoring for your API Gateway deployments and have a rollback strategy in case of issues. Terraform's state management can help revert to previous configurations.
• Terraform Best Practices: Follow general Terraform best practices like using modules for reusable components, managing secrets securely, and implementing proper testing.

By understanding these nuances and employing the right techniques, you can effectively manage your API Gateway deployments with Terraform, ensuring consistency, reliability, and ease of maintenance.

Solutions:

Key Points:

• Hashing for Triggers: Hash relevant resources within the triggers block to ensure accurate change detection.
• Stage Dependencies: Make your aws_api_gateway_stage resource depend on the aws_api_gateway_deployment to guarantee it points to the latest deployment.

By implementing these solutions and considerations, you can maintain up-to-date API Gateway deployments that reflect your Terraform configurations.

By understanding the relationship between API Gateway deployments and stages, and by implementing explicit triggers or lifecycle configurations, you can ensure your Terraform code consistently deploys the correct API Gateway configuration. Remember to hash relevant resources, manage stage dependencies, and consider additional factors like deployment frequency and rollback mechanisms for robust and reliable API Gateway management with Terraform.

• aws_apigatewayv2_deployment not deploying · Issue #12961 ... | I'm trying to build an app which will deploy the new apigatewayv2 websocket app when the code updates. I've got this working on the original aws_api_gateway_deployment by using a stage_description....
• amazon web services - Terraform API Gateway not deploying - Stack ... | Mar 14, 2023 ... In my api gateway deployment resource, I've added triggers to trigger deployment. I made a dummy commit to update one of the integration resources but it's ...
• aws_api_gateway_deployment doesn't get updated after changes ... | aws_api_gateway_deployment doesn't get updated after a dependent resource changes. For example, if I change a aws_api_gateway_integration resource to modify the request_template property, aws_api_g...
• AWS API Gateway Stage seems to point to old Deployment even ... | Using this configuration: resource "aws_api_gateway_stage" "this" { stage_name = var.stage_name rest_api_id = aws_api_gateway_rest_api.this.id deployment_id = aws_api_gateway_deployment.this.id } resource "aws_api_gateway_deployment" "this" { rest_api_id = aws_api_gateway_rest_api.this.id triggers = { redeployment = sha1(jsonencode([ data.aws_iam_policy_document.this.json, ])) } lifecycle { create_before_destroy = true } depends_...
• API Gateway deployment breaks unless manually deployed? : r/aws | Posted by u/Forumpy - 1 vote and 7 comments
• Forcing Terraform to deploy a aws_api_gateway_deployment | by ... | Terraform’s aws_api_gateway_deployment won’t deploy subsequent releases in the event that something has changed in an integration, method…
• Aws api gateway stage and deployment: log group skip_destroy ... | I’m a terraform beginner, trying to deploy an api gateway with integration to a vpc link. When I terraform apply on my project, neither the aws_apigatewayv2_stage resource nor the aws_apigatewayv2_deployment resource that I have defined in my files actually result in the corresponding stage and deployment showing up on AWS. Here are the resource blocks I’ve written to define those resources # api gateway stage resource "aws_apigatewayv2_stage" "this" { api_id = aws_apigatewayv2_api.thi...
• Url Versioning with multiple serverless projects under the same API ... | Hi, I am looking for some help with an issue I am facing. I have built an API GW with terraform and I then retrieve the gateway ID in my serverless project, which is a rest API, part of the url scheme contains the version e.g v1/resource or v1/resource/sub_resource. I have now started to add a second API at version 1 which is a separate microservice representing another entity type and I am facing an error as v1 is already used by another stack. Is there a way I can share the /v1 portion to e...
• Create API Gateway Using Terraform | AWS re:Post | Hi,

I am trying to create API Gateway with two methods PUT and POST using Terraform. Here is my code: Simply I want to create below methods under same API gateway using terraform but getting error...