Use CreateFunction with an AWS SDK or CLI

The following code examples show how to use CreateFunction.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example:

• Get started with functions

.NET

AWS SDK for .NET

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

    /// <summary>
    /// Creates a new Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the function.</param>
    /// <param name="s3Bucket">The Amazon Simple Storage Service (Amazon S3)
    /// bucket where the zip file containing the code is located.</param>
    /// <param name="s3Key">The Amazon S3 key of the zip file.</param>
    /// <param name="role">The Amazon Resource Name (ARN) of a role with the
    /// appropriate Lambda permissions.</param>
    /// <param name="handler">The name of the handler function.</param>
    /// <returns>The Amazon Resource Name (ARN) of the newly created
    /// Lambda function.</returns>
    public async Task<string> CreateLambdaFunctionAsync(
        string functionName,
        string s3Bucket,
        string s3Key,
        string role,
        string handler)
    {
        // Defines the location for the function code.
        // S3Bucket - The S3 bucket where the file containing
        //            the source code is stored.
        // S3Key    - The name of the file containing the code.
        var functionCode = new FunctionCode
        {
            S3Bucket = s3Bucket,
            S3Key = s3Key,
        };

        var createFunctionRequest = new CreateFunctionRequest
        {
            FunctionName = functionName,
            Description = "Created by the Lambda .NET API",
            Code = functionCode,
            Handler = handler,
            Runtime = Runtime.Dotnet6,
            Role = role,
        };

        var reponse = await _lambdaService.CreateFunctionAsync(createFunctionRequest);
        return reponse.FunctionArn;
    }

• For API details, see CreateFunction in AWS SDK for .NET API Reference.

C++

SDK for C++

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::CreateFunctionRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        request.SetDescription(LAMBDA_DESCRIPTION); // Optional.
#if USE_CPP_LAMBDA_FUNCTION
        request.SetRuntime(Aws::Lambda::Model::Runtime::provided_al2);
        request.SetTimeout(15);
        request.SetMemorySize(128);

        // Assume the AWS Lambda function was built in Docker with same architecture
        // as this code.
#if  defined(__x86_64__)
        request.SetArchitectures({Aws::Lambda::Model::Architecture::x86_64});
#elif defined(__aarch64__)
        request.SetArchitectures({Aws::Lambda::Model::Architecture::arm64});
#else
#error "Unimplemented architecture"
#endif // defined(architecture)
#else
        request.SetRuntime(Aws::Lambda::Model::Runtime::python3_8);
#endif
        request.SetRole(roleArn);
        request.SetHandler(LAMBDA_HANDLER_NAME);
        request.SetPublish(true);
        Aws::Lambda::Model::FunctionCode code;
        std::ifstream ifstream(INCREMENT_LAMBDA_CODE.c_str(),
                               std::ios_base::in | std::ios_base::binary);
        if (!ifstream.is_open()) {
            std::cerr << "Error opening file " << INCREMENT_LAMBDA_CODE << "." << std::endl;

#if USE_CPP_LAMBDA_FUNCTION
            std::cerr
                    << "The cpp Lambda function must be built following the instructions in the cpp_lambda/README.md file. "
                    << std::endl;
#endif
            deleteIamRole(clientConfig);
            return false;
        }

        Aws::StringStream buffer;
        buffer << ifstream.rdbuf();

        code.SetZipFile(Aws::Utils::ByteBuffer((unsigned char *) buffer.str().c_str(),
                                               buffer.str().length()));
        request.SetCode(code);

        Aws::Lambda::Model::CreateFunctionOutcome outcome = client.CreateFunction(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda function was successfully created. " << seconds
                      << " seconds elapsed." << std::endl;
            break;
        }

        else {
            std::cerr << "Error with CreateFunction. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            deleteIamRole(clientConfig);
            return false;
        }

• For API details, see CreateFunction in AWS SDK for C++ API Reference.

CLI

AWS CLI

To create a Lambda function

The following create-function example creates a Lambda function named my-function.

aws lambda create-function \
    --function-name my-function \
    --runtime nodejs18.x \
    --zip-file fileb://my-function.zip \
    --handler my-function.handler \
    --role arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-tges6bf4

Contents of my-function.zip:

This file is a deployment package that contains your function code and any dependencies.

Output:

{
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "PFn4S+er27qk+UuZSTKEQfNKG/XNn7QJs90mJgq6oH8=",
    "FunctionName": "my-function",
    "CodeSize": 308,
    "RevisionId": "873282ed-4cd3-4dc8-a069-d0c647e470c6",
    "MemorySize": 128,
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
    "Version": "$LATEST",
    "Role": "arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-zgur6bf4",
    "Timeout": 3,
    "LastModified": "2023-10-14T22:26:11.234+0000",
    "Handler": "my-function.handler",
    "Runtime": "nodejs18.x",
    "Description": ""
}

For more information, see AWS Lambda Function Configuration in the AWS Lambda Developer Guide.

• For API details, see CreateFunction in AWS CLI Command Reference.

Go

SDK for Go V2

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// CreateFunction creates a new Lambda function from code contained in the zipPackage
// buffer. The specified handlerName must match the name of the file and function
// contained in the uploaded code. The role specified by iamRoleArn is assumed by
// Lambda and grants specific permissions.
// When the function already exists, types.StateActive is returned.
// When the function is created, a lambda.FunctionActiveV2Waiter is used to wait until the
// function is active.
func (wrapper FunctionWrapper) CreateFunction(functionName string, handlerName string,
	iamRoleArn *string, zipPackage *bytes.Buffer) types.State {
	var state types.State
	_, err := wrapper.LambdaClient.CreateFunction(context.TODO(), &lambda.CreateFunctionInput{
		Code:         &types.FunctionCode{ZipFile: zipPackage.Bytes()},
		FunctionName: aws.String(functionName),
		Role:         iamRoleArn,
		Handler:      aws.String(handlerName),
		Publish:      true,
		Runtime:      types.RuntimePython38,
	})
	if err != nil {
		var resConflict *types.ResourceConflictException
		if errors.As(err, &resConflict) {
			log.Printf("Function %v already exists.\n", functionName)
			state = types.StateActive
		} else {
			log.Panicf("Couldn't create function %v. Here's why: %v\n", functionName, err)
		}
	} else {
		waiter := lambda.NewFunctionActiveV2Waiter(wrapper.LambdaClient)
		funcOutput, err := waiter.WaitForOutput(context.TODO(), &lambda.GetFunctionInput{
			FunctionName: aws.String(functionName)}, 1*time.Minute)
		if err != nil {
			log.Panicf("Couldn't wait for function %v to be active. Here's why: %v\n", functionName, err)
		} else {
			state = funcOutput.Configuration.State
		}
	}
	return state
}

• For API details, see CreateFunction in AWS SDK for Go API Reference.

Java

SDK for Java 2.x

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

import software.amazon.awssdk.core.SdkBytes;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.lambda.LambdaClient;
import software.amazon.awssdk.services.lambda.model.CreateFunctionRequest;
import software.amazon.awssdk.services.lambda.model.FunctionCode;
import software.amazon.awssdk.services.lambda.model.CreateFunctionResponse;
import software.amazon.awssdk.services.lambda.model.GetFunctionRequest;
import software.amazon.awssdk.services.lambda.model.GetFunctionResponse;
import software.amazon.awssdk.services.lambda.model.LambdaException;
import software.amazon.awssdk.services.lambda.model.Runtime;
import software.amazon.awssdk.services.lambda.waiters.LambdaWaiter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

/**
 * This code example requires a ZIP or JAR that represents the code of the
 * Lambda function.
 * If you do not have a ZIP or JAR, please refer to the following document:
 *
 * https://github.com/aws-doc-sdk-examples/tree/master/javav2/usecases/creating_workflows_stepfunctions
 *
 * Also, set up your development environment, including your credentials.
 *
 * For information, see this documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */

public class CreateFunction {
    public static void main(String[] args) {

        final String usage = """

                Usage:
                    <functionName> <filePath> <role> <handler>\s

                Where:
                    functionName - The name of the Lambda function.\s
                    filePath - The path to the ZIP or JAR where the code is located.\s
                    role - The role ARN that has Lambda permissions.\s
                    handler - The fully qualified method name (for example, example.Handler::handleRequest). \s
                """;

        if (args.length != 4) {
            System.out.println(usage);
            System.exit(1);
        }

        String functionName = args[0];
        String filePath = args[1];
        String role = args[2];
        String handler = args[3];
        Region region = Region.US_WEST_2;
        LambdaClient awsLambda = LambdaClient.builder()
                .region(region)
                .build();

        createLambdaFunction(awsLambda, functionName, filePath, role, handler);
        awsLambda.close();
    }

    public static void createLambdaFunction(LambdaClient awsLambda,
            String functionName,
            String filePath,
            String role,
            String handler) {

        try {
            LambdaWaiter waiter = awsLambda.waiter();
            InputStream is = new FileInputStream(filePath);
            SdkBytes fileToUpload = SdkBytes.fromInputStream(is);

            FunctionCode code = FunctionCode.builder()
                    .zipFile(fileToUpload)
                    .build();

            CreateFunctionRequest functionRequest = CreateFunctionRequest.builder()
                    .functionName(functionName)
                    .description("Created by the Lambda Java API")
                    .code(code)
                    .handler(handler)
                    .runtime(Runtime.JAVA8)
                    .role(role)
                    .build();

            // Create a Lambda function using a waiter.
            CreateFunctionResponse functionResponse = awsLambda.createFunction(functionRequest);
            GetFunctionRequest getFunctionRequest = GetFunctionRequest.builder()
                    .functionName(functionName)
                    .build();
            WaiterResponse<GetFunctionResponse> waiterResponse = waiter.waitUntilFunctionExists(getFunctionRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            System.out.println("The function ARN is " + functionResponse.functionArn());

        } catch (LambdaException | FileNotFoundException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}

• For API details, see CreateFunction in AWS SDK for Java 2.x API Reference.

JavaScript

SDK for JavaScript (v3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

const createFunction = async (funcName, roleArn) => {
  const client = new LambdaClient({});
  const code = await readFile(`${dirname}../functions/${funcName}.zip`);

  const command = new CreateFunctionCommand({
    Code: { ZipFile: code },
    FunctionName: funcName,
    Role: roleArn,
    Architectures: [Architecture.arm64],
    Handler: "index.handler", // Required when sending a .zip file
    PackageType: PackageType.Zip, // Required when sending a .zip file
    Runtime: Runtime.nodejs16x, // Required when sending a .zip file
  });

  return client.send(command);
};

• For API details, see CreateFunction in AWS SDK for JavaScript API Reference.

Kotlin

SDK for Kotlin

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

suspend fun createNewFunction(
    myFunctionName: String,
    s3BucketName: String,
    myS3Key: String,
    myHandler: String,
    myRole: String,
): String? {
    val functionCode =
        FunctionCode {
            s3Bucket = s3BucketName
            s3Key = myS3Key
        }

    val request =
        CreateFunctionRequest {
            functionName = myFunctionName
            code = functionCode
            description = "Created by the Lambda Kotlin API"
            handler = myHandler
            role = myRole
            runtime = Runtime.Java8
        }

    LambdaClient { region = "us-west-2" }.use { awsLambda ->
        val functionResponse = awsLambda.createFunction(request)
        awsLambda.waitUntilFunctionActive {
            functionName = myFunctionName
        }
        return functionResponse.functionArn
    }
}

• For API details, see CreateFunction in AWS SDK for Kotlin API reference.

PHP

SDK for PHP

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

    public function createFunction($functionName, $role, $bucketName, $handler)
    {
        //This assumes the Lambda function is in an S3 bucket.
        return $this->customWaiter(function () use ($functionName, $role, $bucketName, $handler) {
            return $this->lambdaClient->createFunction([
                'Code' => [
                    'S3Bucket' => $bucketName,
                    'S3Key' => $functionName,
                ],
                'FunctionName' => $functionName,
                'Role' => $role['Arn'],
                'Runtime' => 'python3.9',
                'Handler' => "$handler.lambda_handler",
            ]);
        });
    }

• For API details, see CreateFunction in AWS SDK for PHP API Reference.

PowerShell

Tools for PowerShell

Example 1: This example creates a new C# (dotnetcore1.0 runtime) function named MyFunction in AWS Lambda, providing the compiled binaries for the function from a zip file on the local file system (relative or absolute paths may be used). C# Lambda functions specify the handler for the function using the designation AssemblyName::Namespace.ClassName::MethodName. You should replace the assembly name (without .dll suffix), namespace, class name and method name parts of the handler spec appropriately. The new function will have environment variables 'envvar1' and 'envvar2' set up from the provided values.

Publish-LMFunction -Description "My C# Lambda Function" `
        -FunctionName MyFunction `
        -ZipFilename .\MyFunctionBinaries.zip `
        -Handler "AssemblyName::Namespace.ClassName::MethodName" `
        -Role "arn:aws:iam::123456789012:role/LambdaFullExecRole" `
        -Runtime dotnetcore1.0 `
        -Environment_Variable @{ "envvar1"="value";"envvar2"="value" }

Output:

CodeSha256       : /NgBMd...gq71I=
CodeSize         : 214784
DeadLetterConfig :
Description      : My C# Lambda Function
Environment      : Amazon.Lambda.Model.EnvironmentResponse
FunctionArn      : arn:aws:lambda:us-west-2:123456789012:function:ToUpper
FunctionName     : MyFunction
Handler          : AssemblyName::Namespace.ClassName::MethodName
KMSKeyArn        :
LastModified     : 2016-12-29T23:50:14.207+0000
MemorySize       : 128
Role             : arn:aws:iam::123456789012:role/LambdaFullExecRole
Runtime          : dotnetcore1.0
Timeout          : 3
Version          : $LATEST
VpcConfig        :

Example 2: This example is similar to the previous one except the function binaries are first uploaded to an Amazon S3 bucket (which must be in the same region as the intended Lambda function) and the resulting S3 object is then referenced when creating the function.

Write-S3Object -BucketName mybucket -Key MyFunctionBinaries.zip -File .\MyFunctionBinaries.zip    
Publish-LMFunction -Description "My C# Lambda Function" `
        -FunctionName MyFunction `
        -BucketName mybucket `
        -Key MyFunctionBinaries.zip `
        -Handler "AssemblyName::Namespace.ClassName::MethodName" `
        -Role "arn:aws:iam::123456789012:role/LambdaFullExecRole" `
        -Runtime dotnetcore1.0 `
        -Environment_Variable @{ "envvar1"="value";"envvar2"="value" }

• For API details, see CreateFunction in AWS Tools for PowerShell Cmdlet Reference.

Python

SDK for Python (Boto3)

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def create_function(
        self, function_name, handler_name, iam_role, deployment_package
    ):
        """
        Deploys a Lambda function.

        :param function_name: The name of the Lambda function.
        :param handler_name: The fully qualified name of the handler function. This
                             must include the file name and the function name.
        :param iam_role: The IAM role to use for the function.
        :param deployment_package: The deployment package that contains the function
                                   code in .zip format.
        :return: The Amazon Resource Name (ARN) of the newly created function.
        """
        try:
            response = self.lambda_client.create_function(
                FunctionName=function_name,
                Description="AWS Lambda doc example",
                Runtime="python3.8",
                Role=iam_role.arn,
                Handler=handler_name,
                Code={"ZipFile": deployment_package},
                Publish=True,
            )
            function_arn = response["FunctionArn"]
            waiter = self.lambda_client.get_waiter("function_active_v2")
            waiter.wait(FunctionName=function_name)
            logger.info(
                "Created function '%s' with ARN: '%s'.",
                function_name,
                response["FunctionArn"],
            )
        except ClientError:
            logger.error("Couldn't create function %s.", function_name)
            raise
        else:
            return function_arn

• For API details, see CreateFunction in AWS SDK for Python (Boto3) API Reference.

Ruby

SDK for Ruby

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

class LambdaWrapper
  attr_accessor :lambda_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Deploys a Lambda function.
  #
  # @param function_name: The name of the Lambda function.
  # @param handler_name: The fully qualified name of the handler function. This
  #                      must include the file name and the function name.
  # @param role_arn: The IAM role to use for the function.
  # @param deployment_package: The deployment package that contains the function
  #                            code in .zip format.
  # @return: The Amazon Resource Name (ARN) of the newly created function.
  def create_function(function_name, handler_name, role_arn, deployment_package)
    response = @lambda_client.create_function({
                                                role: role_arn.to_s,
                                                function_name: function_name,
                                                handler: handler_name,
                                                runtime: "ruby2.7",
                                                code: {
                                                  zip_file: deployment_package
                                                },
                                                environment: {
                                                  variables: {
                                                    "LOG_LEVEL" => "info"
                                                  }
                                                }
                                              })
    @lambda_client.wait_until(:function_active_v2, { function_name: function_name}) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
    response
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error creating #{function_name}:\n #{e.message}")
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
  end

• For API details, see CreateFunction in AWS SDK for Ruby API Reference.

Rust

SDK for Rust

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

    /**
     * Create a function, uploading from a zip file.
     */
    pub async fn create_function(&self, zip_file: PathBuf) -> Result<String, anyhow::Error> {
        let code = self.prepare_function(zip_file, None).await?;

        let key = code.s3_key().unwrap().to_string();

        let role = self.create_role().await.map_err(|e| anyhow!(e))?;

        info!("Created iam role, waiting 15s for it to become active");
        tokio::time::sleep(Duration::from_secs(15)).await;

        info!("Creating lambda function {}", self.lambda_name);
        let _ = self
            .lambda_client
            .create_function()
            .function_name(self.lambda_name.clone())
            .code(code)
            .role(role.arn())
            .runtime(aws_sdk_lambda::types::Runtime::Providedal2)
            .handler("_unused")
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        self.lambda_client
            .publish_version()
            .function_name(self.lambda_name.clone())
            .send()
            .await?;

        Ok(key)
    }

    /**
     * Upload function code from a path to a zip file.
     * The zip file must have an AL2 Linux-compatible binary called `bootstrap`.
     * The easiest way to create such a zip is to use `cargo lambda build --output-format Zip`.
     */
    async fn prepare_function(
        &self,
        zip_file: PathBuf,
        key: Option<String>,
    ) -> Result<FunctionCode, anyhow::Error> {
        let body = ByteStream::from_path(zip_file).await?;

        let key = key.unwrap_or_else(|| format!("{}_code", self.lambda_name));

        info!("Uploading function code to s3://{}/{}", self.bucket, key);
        let _ = self
            .s3_client
            .put_object()
            .bucket(self.bucket.clone())
            .key(key.clone())
            .body(body)
            .send()
            .await?;

        Ok(FunctionCode::builder()
            .s3_bucket(self.bucket.clone())
            .s3_key(key)
            .build())
    }

• For API details, see CreateFunction in AWS SDK for Rust API reference.

SAP ABAP

SDK for SAP ABAP

Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository.

    TRY.
        lo_lmd->createfunction(
            iv_functionname = iv_function_name
            iv_runtime = `python3.9`
            iv_role = iv_role_arn
            iv_handler = iv_handler
            io_code = io_zip_file
            iv_description = 'AWS Lambda code example'
        ).
        MESSAGE 'Lambda function created.' TYPE 'I'.
      CATCH /aws1/cx_lmdcodesigningcfgno00.
        MESSAGE 'Code signing configuration does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodestorageexcdex.
        MESSAGE 'Maximum total code size per account exceeded.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodeverification00.
        MESSAGE 'Code signature failed one or more validation checks for signature mismatch or expiration.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvalidcodesigex.
        MESSAGE 'Code signature failed the integrity check.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.

• For API details, see CreateFunction in AWS SDK for SAP ABAP API reference.