aws-lambda.md

description
This page provides the technical details of the AWS Lambda policy

AWS Lambda

Overview

The AWS Lambda policy can be used to request a Lambda instead of or in addition to the backend.

By default, the Lambda is called in addition to the backend, meaning the consumer will not receive the response from the Lambda.

Functional and implementation information for the aws-lambda policy is organized into the following sections:

• Examples
• Configuration
• Errors
• Changelogs

Examples

{% hint style="warning" %} This policy can only be applied to v2 APIs. It cannot be applied to v4 message APIs or v4 proxy APIs. {% endhint %}

{% tabs %} {% tab title="Proxy API example" %} Sample policy configuration:

"configuration": {
    "variables": [
      {
        "name": "lambdaResponse",
        "value": "{#jsonPath(#lambdaResponse.content, '$')}"
      }
    ],
    "secretKey": "secretKey",
    "accessKey":"accessKey",
    "payload": "{ \"key\": \"value\" }",
    "scope": "REQUEST",
    "function": "lambda-example",
    "region": "us-east-1",
    "sendToConsumer": true,
    "endpoint": "http://aws-lambda-url/function"
}

{% endtab %} {% endtabs %}

Configuration

Phases

The phases checked below are supported by the aws-lambda policy:

v2 Phases	Compatible?	v4 Phases	Compatible?
onRequest	true	onRequest	false
onResponse	true	onResponse	false
onRequestContent	true	onMessageRequest	false
onResponseContent	true	onMessageResponse	false

Options

You can configure the aws-lambda policy with the following options:

Property	Required	Description	Type	Default
scope	true	The scope on which apply the policy	string	REQUEST
region	true	The AWS region	string	us-east-1
accessKey	false	AWS Access Key	string	-
secretKey	false	AWS Secret Key	string	-
function	true	The name of the AWS Lambda function to call	string	-
payload	false	Payload of the request to AWS Lambda function	string	-
variables	false	The variables to set in the execution context when retrieving content of HTTP call (support EL)	List of variables	-
sendToConsumer	false	Check this option if you want to send the response of the lambda to the initial consumer without going to the final upstream (endpoints) selected by the gateway.	boolean	false

Errors

HTTP status code	Message
500	Request processing broken

You can override the default response provided by the policy with the response templates feature. These templates must be defined at the API level with the APIM Console Proxy > Response Templates function.

The error keys sent by this policy are as follows:

Key	Default status	Parameters
AWS_LAMBDA_INVALID_RESPONSE	500	-
AWS_LAMBDA_INVALID_STATUS_CODE	400	-

Changelogs

{% @github-files/github-code-block url="https://github.com/gravitee-io/gravitee-policy-json-xml/blob/master/CHANGELOG.md" %}