Add support for Lambda (#76)

README.md

@@ -15,6 +15,7 @@ At the moment, this library provides the following:
 -   `SSM`: allows to retrieve a parameter from AWS Systems Manager
 -   `Kinesis`: allows to list streams, create streams, put records, list shards, get shard iterators, and get records from AWS Kinesis.
 -   `EventBridge`: allows to put events to AWS EventBridge.
+-   `Lambda`: allows to invoke functions in AWS Lambda.
 -   `V4 signature`: allows to sign requests to amazon AWS services
 -   `KinesisClient`: allows all APIs for Kinesis available by AWS.
 
@@ -375,6 +376,34 @@ export default async function () {
 }
 ```
 
+### Lambda
+
+Consult the `LambdaClient` [dedicated k6 documentation page](https://k6.io/docs/javascript-api/jslib/aws/lambdaclient) for more details on its methods and how to use it.
+
+```javascript
+import { AWSConfig, LambdaClient } from 'https://jslib.k6.io/aws/0.11.0/lambda.js'
+import { check } from 'k6';
+
+const awsConfig = new AWSConfig({
+    region: __ENV.AWS_REGION,
+    accessKeyId: __ENV.AWS_ACCESS_KEY_ID,
+    secretAccessKey: __ENV.AWS_SECRET_ACCESS_KEY,
+    sessionToken: __ENV.AWS_SESSION_TOKEN,
+})
+
+const lambdaClient = new LambdaClient(awsConfig)
+
+export default async function () {
+    const response = await lambdaClient.invoke('add-numbers', JSON.stringify({x: 1, y: 2}))
+
+    check(response, {
+        'status is 200': (r) => r.statusCode === 200,
+        'payload is 3': (r) => r.payload === 3,
+    })
+}
+
+```
+
 ## Development
 
 ### Contributing

build/lambda.js.LICENSE.txt

@@ -0,0 +1 @@
+/*! regenerator-runtime -- Copyright (c) 2014-present, Facebook, Inc. -- license (MIT): https://github.com/facebook/regenerator/blob/main/LICENSE */

examples/lambda.js

@@ -0,0 +1,20 @@
+import { AWSConfig, LambdaClient } from '../build/lambda.js'
+import { check } from 'k6';
+
+const awsConfig = new AWSConfig({
+    region: __ENV.AWS_REGION,
+    accessKeyId: __ENV.AWS_ACCESS_KEY_ID,
+    secretAccessKey: __ENV.AWS_SECRET_ACCESS_KEY,
+    sessionToken: __ENV.AWS_SESSION_TOKEN,
+})
+
+const lambdaClient = new LambdaClient(awsConfig)
+
+export default async function () {
+    const response = await lambdaClient.invoke('add-numbers', JSON.stringify({x: 1, y: 2}))
+
+    check(response, {
+        'status is 200': (r) => r.statusCode === 200,
+        'payload is 3': (r) => r.payload === 3,
+    })
+}

localstack/init/ready.d/lambda.sh

@@ -1,21 +1,18 @@
 #!/bin/bash
 
-FUNCTION_NAME="test-jslib-aws-lambda"
+testdata_folder="/etc/localstack/init/testdata/lambda"
+zip_dir=/tmp/lambda
+mkdir -p "$zip_dir"
 
-# Create a dummy lambda function responding with a static string "Hello World!"
-cat >index.js <<EOF
-exports.handler = async function(event, context) {
-    return "Hello World!";
-}
-EOF
+for file in "$testdata_folder"/*; do
+  function_name=$(basename "$file")
+  function_zip="$zip_dir/$function_name.zip"
+  (cd "$file" || exit; zip "$function_zip" ./*)
 
-# Create a zip file containing the lambda function
-zip lambda.zip index.js
-
-# Create a dummy lambda function responding with a static string "Hello World!"
-awslocal lambda create-function \
-    --function-name "$FUNCTION_NAME" \
-    --runtime nodejs18.x \
-    --handler index.handler \
-    --zip-file fileb://lambda.zip \
-    --role arn:aws:iam::123456789012:role/irrelevant
+  awslocal lambda create-function \
+      --function-name "$function_name" \
+      --runtime nodejs18.x \
+      --zip-file "fileb://$function_zip" \
+      --handler index.handler \
+      --role arn:aws:iam::000000000000:role/lambda-role
+done

localstack/init/testdata/lambda/test-fail/index.js

@@ -0,0 +1,3 @@
+exports.handler = async (event) => {
+    throw new Error(event)
+};

localstack/init/testdata/lambda/test-product/index.js

@@ -0,0 +1,4 @@
+exports.handler = async (event) => {
+    console.log('received event:', JSON.stringify(event));
+    return event.a * event.b
+};

src/index.ts

@@ -18,3 +18,4 @@ export {
 export { SQSClient } from './sqs'
 export { KinesisClient } from './internal/kinesis'
 export { EventBridgeClient } from './internal/event-bridge'
+export { LambdaClient, LambdaInvocationError } from './lambda'

src/internal/error.ts

@@ -1,4 +1,5 @@
 import { parseHTML } from 'k6/html'
+import { Response } from 'k6/http'
 
 /**
  * Base class to derive errors from
@@ -35,4 +36,15 @@ export class AWSError extends Error {
         const doc = parseHTML(xmlDocument)
         return new AWSError(doc.find('Message').text(), doc.find('Code').text())
     }
+
+    static parse(response: Response): AWSError {
+        if (response.headers['Content-Type'] === 'application/json') {
+            const error = response.json() as any;
+            const message = error.Message || error.message || error.__type || 'An error occurred on the server side';
+            const code = response.headers['X-Amzn-Errortype'] || error.__type
+            return new AWSError(message, code)
+        } else {
+            return AWSError.parseXML(response.body as string);
+        }
+    }
 }

src/internal/lambda.ts

@@ -1,22 +1,21 @@
 import http, { RefinedResponse, ResponseType } from 'k6/http'
+import encoding from 'k6/encoding';
 
 import { AWSClient } from './client'
 import { AWSConfig } from './config'
 import { AWSError } from './error'
-import { JSONObject } from './json'
 import { InvalidSignatureError, SignatureV4 } from './signature'
 import { AMZ_TARGET_HEADER } from './constants'
-import { HTTPHeaders, HTTPMethod } from './http'
+import { HTTPHeaders, HTTPMethod, QueryParameterBag } from './http'
+
 
 /**
  * Class allowing to interact with Amazon AWS's Lambda service
  */
 export class LambdaClient extends AWSClient {
-    method: HTTPMethod
-
-    commonHeaders: HTTPHeaders
-
-    signature: SignatureV4
+    private readonly signature: SignatureV4
+    private readonly commonHeaders: HTTPHeaders
+    private readonly method: HTTPMethod
 
     constructor(awsConfig: AWSConfig) {
         super(awsConfig, 'lambda')
@@ -42,134 +41,120 @@ export class LambdaClient extends AWSClient {
     /**
      * Invoke an AWS Lambda function
      *
-     * @param {InvokeInput} input - The input for the PutEvents operation.
-     * @throws {LambdaServiceError}
-     * @throws {InvalidSignatureError}
+     * @param {string} name - The name of the function
+     * @param {string} payload - The payload to send to function
+     * @param {InvocationOptions} options - Additional options to customize invocation
+     *
+     * @throws {LambdaInvocationError}
      */
-    async invoke(input: InvokeInput) {
-        const qualifier = input.Qualifier ? `?Qualifier=${input.Qualifier}` : ''
+    async invoke(
+        name: string,
+        payload: string,
+        options: InvocationOptions = {}
+    ): Promise<InvocationResponse> {
+        const query: QueryParameterBag = {};
+        const invocationType = options.invocationType || 'RequestResponse'
         const headers = {
             ...this.commonHeaders,
-            [AMZ_TARGET_HEADER]: `AWSLambda.${input.InvocationType}`,
-            'X-Amz-Invocation-Type': input.InvocationType,
-            'X-Amz-Log-Type': input.LogType || 'None',
-        };
-
-        if (input.ClientContext) {
-            headers['X-Amz-Client-Context'] = input.ClientContext
+            [AMZ_TARGET_HEADER]: `AWSLambda.${invocationType}`,
+            'X-Amz-Invocation-Type': invocationType,
+            'X-Amz-Log-Type': options.logType || 'None'
+        }
+        if (options.clientContext) {
+            headers['X-Amz-Client-Context'] = options.clientContext
+        }
+        if (options.qualifier) {
+            query['Qualifier'] = options.qualifier;
         }
 
         const signedRequest = this.signature.sign(
             {
                 method: this.method,
                 endpoint: this.endpoint,
-                path: `/2015-03-31/functions/${input.FunctionName}/invocations${qualifier}`,
+                path: `/2015-03-31/functions/${name}/invocations`,
+                query,
                 headers,
-                body: JSON.stringify(input.Payload ?? ''),
+                body: payload || ''
             },
             {}
         )
 
         const res = await http.asyncRequest(this.method, signedRequest.url, signedRequest.body, {
             headers: signedRequest.headers,
         })
-        this._handle_error(LambdaOperation.Invoke, res)
-
-        if(input.InvocationType === 'Event') {
-            return
+        this._handle_error(res)
+
+        const logResult = res.headers['X-Amz-Log-Result']
+        const response = {
+            executedVersion: res.headers['X-Amz-Executed-Version'],
+            logResult: logResult ? encoding.b64decode(logResult, 'std', 's') : undefined,
+            statusCode: res.status,
+            payload: res.body as string
         }
 
-        return res.json()
+        const functionError = res.headers['X-Amz-Function-Error']
+        if (functionError) {
+            throw new LambdaInvocationError(functionError, response)
+        } else {
+            return response
+        }
     }
 
-    _handle_error(
-        operation: LambdaOperation,
+    private _handle_error(
         response: RefinedResponse<ResponseType | undefined>
     ) {
-        const errorCode = response.error_code
-        if (errorCode === 0) {
-            return
-        }
+        const errorCode: number = response.error_code
+        const errorMessage: string = response.error
 
-        const error = response.json() as JSONObject
-        if (errorCode >= 1400 && errorCode <= 1499) {
-            // In the event of certain errors, the message is not set.
-            // Also, note the inconsistency in casing...
-            const errorMessage: string =
-                (error.Message as string) || (error.message as string) || (error.__type as string)
-
-            // Handle specifically the case of an invalid signature
-            if (error.__type === 'InvalidSignatureException') {
-                throw new InvalidSignatureError(errorMessage, error.__type)
-            }
-
-            // Otherwise throw a standard service error
-            throw new LambdaServiceError(errorMessage, error.__type as string, operation)
+        if (errorMessage == '' && errorCode === 0) {
+            return
         }
 
-        if (errorCode === 1500) {
-            throw new LambdaServiceError(
-                'An error occured on the server side',
-                'InternalServiceError',
-                operation
-            )
+        const awsError = AWSError.parse(response)
+        switch (awsError.code) {
+            case 'AuthorizationHeaderMalformed':
+            case 'InvalidSignatureException':
+                throw new InvalidSignatureError(awsError.message, awsError.code)
+            default:
+                throw awsError
         }
     }
 }
 
-enum LambdaOperation {
-    Invoke = 'Invoke',
-}
+export class LambdaInvocationError extends Error {
+    response: InvocationResponse
 
+    constructor(message: string, response: InvocationResponse) {
+        super(`${message}: ${response.payload}`)
+        this.response = response
+    }
+}
 
-/**
- * Represents the input for an Invoke operation.
- */
-interface InvokeInput {
-    /**
-     * The name of the Lambda function, version, or alias.
-     *
-     * Supported names formats:
-     *   - Function name: `my-function` (name-only), `my-function:v1` (with alias).
-     *   - Function ARM: `arn:aws:lambda:us-west-2:123456789012:function:my-function`.
-     *   - Partial ARN: `123456789012:function:my-function`.
-     */
-    FunctionName: string
+interface InvocationOptions {
     /**
      * Defines whether the function is invoked synchronously or asynchronously.
      * - `RequestResponse` (default): Invoke the function synchronously.
      * - `Event`: Invoke the function asynchronously.
      * - `DryRun`: Validate parameter values and verify that the user or role has permission to invoke the function.
      */
-    InvocationType: 'RequestResponse' | 'Event' | 'DryRun'
+    invocationType?: 'RequestResponse' | 'Event' | 'DryRun';
     /**
      * Set to `Tail` to include the execution log in the response. Applies to synchronously invoked functions only.
      */
-    LogType?: 'None' | 'Tail'
+    logType?: 'None' | 'Tail';
     /**
      * Up to 3,583 bytes of base64-encoded data about the invoking client to pass to the function in the context object.
      */
-    ClientContext?: string
+    clientContext?: string;
     /**
      * Specify a version or alias to invoke a published version of the function.
      */
-    Qualifier?: string
-    Payload?: string
+    qualifier?: string;
 }
 
-export class LambdaServiceError extends AWSError {
-    operation: LambdaOperation
-
-    /**
-     * Constructs a LambdaServiceError
-     *
-     * @param  {string} message - human readable error message
-     * @param  {string} code - A unique short code representing the error that was emitted
-     * @param  {string} operation - Name of the failed Operation
-     */
-    constructor(message: string, code: string, operation: LambdaOperation) {
-        super(message, code)
-        this.name = 'LambdaServiceError'
-        this.operation = operation
-    }
-}
+interface InvocationResponse {
+    statusCode: number;
+    executedVersion?: string;
+    logResult?: string;
+    payload?: string;
+}

src/lambda.ts

@@ -2,6 +2,6 @@
 export { AWSConfig, InvalidAWSConfigError } from './internal/config'
 export { InvalidSignatureError } from './internal/signature'
 export {
-    LambdaServiceError,
+    LambdaInvocationError,
     LambdaClient
 } from './internal/lambda'