mirror of
https://github.com/swift-server/swift-aws-lambda-runtime.git
synced 2026-05-03 07:22:27 +00:00
Sébastien Stormacq
dee635267b
Change Examples, README, and doc to refer to https://github.org/awslabs instead of https://github.org/swift-server --------- Co-authored-by: Sebastien Stormacq <stormacq@amazon.lu>
90 lines
4.0 KiB
Markdown
90 lines
4.0 KiB
Markdown
# Hello JSON
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This is a simple example of an AWS Lambda function that takes a JSON structure as an input parameter and returns a JSON structure as a response.
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The runtime takes care of decoding the input and encoding the output.
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## Code
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The code defines `HelloRequest` and `HelloResponse` data structures to represent the input and output payloads. These structures are typically shared with a client project, such as an iOS application.
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The code creates a `LambdaRuntime` struct. In it's simplest form, the initializer takes a function as an argument. The function is the handler that will be invoked when an event triggers the Lambda function.
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The handler is `(event: HelloRequest, context: LambdaContext)`. The function takes two arguments:
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- the event argument is a `HelloRequest`. It is the parameter passed when invoking the function.
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- the context argument is a `Lambda Context`. It is a description of the runtime context.
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The function return value will be encoded to a `HelloResponse` as your Lambda function response.
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## Build & Package
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To build & archive the package, type the following commands.
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```bash
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swift package archive --allow-network-connections docker
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```
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If there is no error, there is a ZIP file ready to deploy.
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The ZIP file is located at `.build/plugins/AWSLambdaPackager/outputs/AWSLambdaPackager/HelloJSON/HelloJSON.zip`
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## Deploy
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Here is how to deploy using the `aws` command line.
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```bash
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# Replace with your AWS Account ID
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AWS_ACCOUNT_ID=012345678901
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aws lambda create-function \
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--function-name HelloJSON \
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--zip-file fileb://.build/plugins/AWSLambdaPackager/outputs/AWSLambdaPackager/HelloJSON/HelloJSON.zip \
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--runtime provided.al2 \
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--handler provided \
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--architectures arm64 \
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--role arn:aws:iam::${AWS_ACCOUNT_ID}:role/lambda_basic_execution
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```
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The `--architectures` flag is only required when you build the binary on an Apple Silicon machine (Apple M1 or more recent). It defaults to `x64`.
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Be sure to define the `AWS_ACCOUNT_ID` environment variable with your actual AWS account ID (for example: 012345678901).
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## Invoke your Lambda function
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To invoke the Lambda function, use this `aws` command line.
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```bash
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aws lambda invoke \
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--function-name HelloJSON \
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--payload $(echo '{ "name" : "Seb", "age" : 50 }' | base64) \
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out.txt && cat out.txt && rm out.txt
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```
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Note that the payload is expected to be a valid JSON string.
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This should output the following result.
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```
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{
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"StatusCode": 200,
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"ExecutedVersion": "$LATEST"
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}
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{"greetings":"Hello Seb. You look younger than your age."}
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```
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## Undeploy
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When done testing, you can delete the Lambda function with this command.
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```bash
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aws lambda delete-function --function-name HelloJSON
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```
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## ⚠️ Security and Reliability Notice
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These are example applications for demonstration purposes. When deploying such infrastructure in production environments, we strongly encourage you to follow these best practices for improved security and resiliency:
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- Enable access logging on API Gateway ([documentation](https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-logging.html))
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- Ensure that AWS Lambda function is configured for function-level concurrent execution limit ([concurrency documentation](https://docs.aws.amazon.com/lambda/latest/dg/lambda-concurrency.html), [configuration guide](https://docs.aws.amazon.com/lambda/latest/dg/configuration-concurrency.html))
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- Check encryption settings for Lambda environment variables ([documentation](https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars-encryption.html))
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- Ensure that AWS Lambda function is configured for a Dead Letter Queue (DLQ) ([documentation](https://docs.aws.amazon.com/lambda/latest/dg/invocation-async-retain-records.html#invocation-dlq))
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- Ensure that AWS Lambda function is configured inside a VPC when it needs to access private resources ([documentation](https://docs.aws.amazon.com/lambda/latest/dg/configuration-vpc.html), [code example](https://github.com/awslabs/swift-aws-lambda-runtime/tree/main/Examples/ServiceLifecycle%2BPostgres)) |