API Gateway stages are a crucial concept for AWS Certified Developer - Associate exam preparation, particularly in the deployment domain. A stage represents a named reference to a deployment of your API, essentially serving as a snapshot of your API configuration at a specific point in time.
When …API Gateway stages are a crucial concept for AWS Certified Developer - Associate exam preparation, particularly in the deployment domain. A stage represents a named reference to a deployment of your API, essentially serving as a snapshot of your API configuration at a specific point in time.
When you deploy an API in Amazon API Gateway, you must associate it with a stage. Common stage names include 'dev', 'test', 'staging', and 'prod', allowing you to manage different versions of your API simultaneously. Each stage maintains its own configuration settings, including caching, throttling, and logging parameters.
Stage variables are key-value pairs that act as environment variables for your API Gateway stages. They enable you to reference different backend endpoints, Lambda function aliases, or parameter values based on the stage. For example, you might use stage variables to point your 'dev' stage to a development Lambda alias while your 'prod' stage points to a production alias.
Each stage has a unique invoke URL following the pattern: https://{api-id}.execute-api.{region}.amazonaws.com/{stage-name}. This allows clients to access different versions of your API through distinct endpoints.
Canary deployments are supported at the stage level, enabling you to route a percentage of traffic to a new deployment while the majority continues using the existing version. This facilitates safe testing of changes in production environments.
Stages also support stage-level settings such as:
- CloudWatch logging configuration
- Request throttling limits
- API caching settings
- Client certificates for backend authentication
- Web Application Firewall (WAF) integration
Export functionality allows you to export your API definition from any stage in OpenAPI or Swagger format. Understanding stages is essential for implementing proper CI/CD pipelines and managing API lifecycle in AWS environments.
API Gateway Stages - Complete Guide for AWS Developer Associate Exam
What are API Gateway Stages?
API Gateway Stages are named references to a specific deployment of your API. Think of stages as different environments where your API can run, such as dev, test, staging, and prod. Each stage is a snapshot of your API at a particular point in time and can be configured independently.
Why are API Gateway Stages Important?
Stages are crucial for several reasons:
• Environment Separation: They allow you to maintain separate environments for development, testing, and production • Version Management: Different stages can point to different deployments, enabling version control • Independent Configuration: Each stage can have its own settings for caching, throttling, and logging • Canary Deployments: Stages support canary releases for gradual rollouts • Stage Variables: Allow dynamic configuration per stage
How API Gateway Stages Work
1. Deployment Process: When you deploy an API, you select or create a stage. The deployment creates a snapshot of your API configuration.
2. Stage URL Format: Each stage has a unique invoke URL following this pattern: https://{api-id}.execute-api.{region}.amazonaws.com/{stage-name}
3. Stage Variables: These are name-value pairs that act like environment variables. You can use them to: • Reference different Lambda function aliases or versions • Pass configuration values to your backend • Reference different HTTP endpoints per stage
4. Stage Settings: Each stage can be configured with: • Caching: Enable/disable and set cache capacity (0.5GB to 237GB) • Throttling: Set rate limits and burst limits per stage • CloudWatch Logging: Configure logging levels and metrics • X-Ray Tracing: Enable distributed tracing
5. Canary Deployments: You can configure a percentage of traffic to be routed to a canary deployment within a stage for testing new versions safely.
Stage Variables in Practice
Stage variables are referenced using the syntax: ${stageVariables.variableName}
Common use cases include: • Pointing to different Lambda aliases: arn:aws:lambda:region:account:function:myFunction:${stageVariables.lambdaAlias} • Configuring different database endpoints per environment • Setting feature flags
Exam Tips: Answering Questions on API Gateway Stages
1. Remember the URL Structure: Questions may ask about constructing invoke URLs. The stage name is always part of the base path.
2. Stage Variables vs Environment Variables: Stage variables are specific to API Gateway and passed at runtime. Do not confuse them with Lambda environment variables.
3. Caching is Per-Stage: If a question mentions API caching, remember it is configured at the stage level, not the API level.
4. Throttling Hierarchy: Account-level limits apply first, then stage-level, then method-level. Questions about rate limiting often test this hierarchy.
5. Canary Deployments: When asked about gradual rollouts or testing new API versions with minimal risk, canary deployments within stages is the answer.
6. Deployment Required: Any changes to your API must be deployed to a stage before they take effect. This is a common exam topic.
7. Stage Variables and Lambda: Stage variables can reference Lambda aliases, enabling you to point dev stage to $LATEST and prod to a specific version.
8. Export Capabilities: Stages can export API definitions in OpenAPI/Swagger format - useful for documentation questions.
9. Rollback Scenario: To rollback, you deploy a previous deployment to the stage. Each deployment is immutable.
10. CloudWatch Integration: Logging and metrics are configured per stage. Detailed metrics and access logging are common exam topics.