createFunction method

Future<FunctionConfiguration> createFunction({
  1. required FunctionCode code,
  2. required String functionName,
  3. required String role,
  4. String? codeSigningConfigArn,
  5. DeadLetterConfig? deadLetterConfig,
  6. String? description,
  7. Environment? environment,
  8. List<FileSystemConfig>? fileSystemConfigs,
  9. String? handler,
  10. ImageConfig? imageConfig,
  11. String? kMSKeyArn,
  12. List<String>? layers,
  13. int? memorySize,
  14. PackageType? packageType,
  15. bool? publish,
  16. Runtime? runtime,
  17. Map<String, String>? tags,
  18. int? timeout,
  19. TracingConfig? tracingConfig,
  20. VpcConfig? vpcConfig,
})

Creates a Lambda function. To create a function, you need a deployment package and an execution role. The deployment package is a .zip file archive or container image that contains your function code. The execution role grants the function permission to use AWS services, such as Amazon CloudWatch Logs for log streaming and AWS X-Ray for request tracing.

When you create a function, Lambda provisions an instance of the function and its supporting resources. If your function connects to a VPC, this process can take a minute or so. During this time, you can't invoke or modify the function. The State, StateReason, and StateReasonCode fields in the response from GetFunctionConfiguration indicate when the function is ready to invoke. For more information, see Function States.

A function has an unpublished version, and can have published versions and aliases. The unpublished version changes when you update your function's code and configuration. A published version is a snapshot of your function code and configuration that can't be changed. An alias is a named resource that maps to a version, and can be changed to map to a different version. Use the Publish parameter to create version 1 of your function from its initial configuration.

The other parameters let you configure version-specific and function-level settings. You can modify version-specific settings later with UpdateFunctionConfiguration. Function-level settings apply to both the unpublished and published versions of the function, and include tags (TagResource) and per-function concurrency limits (PutFunctionConcurrency).

You can use code signing if your deployment package is a .zip file archive. To enable code signing for this function, specify the ARN of a code-signing configuration. When a user attempts to deploy a code package with UpdateFunctionCode, Lambda checks that the code package has a valid signature from a trusted publisher. The code-signing configuration includes set set of signing profiles, which define the trusted publishers for this function.

If another account or an AWS service invokes your function, use AddPermission to grant permission by creating a resource-based IAM policy. You can grant permissions at the function level, on a version, or on an alias.

To invoke your function directly, use Invoke. To invoke your function in response to events in other AWS services, create an event source mapping (CreateEventSourceMapping), or configure a function trigger in the other service. For more information, see Invoking Functions.

May throw ServiceException. May throw InvalidParameterValueException. May throw ResourceNotFoundException. May throw ResourceConflictException. May throw TooManyRequestsException. May throw CodeStorageExceededException. May throw CodeVerificationFailedException. May throw InvalidCodeSignatureException. May throw CodeSigningConfigNotFoundException.

Parameter code : The code for the function.

Parameter functionName : The name of the Lambda function.

Name formats

  • Function name - my-function.
  • Function ARN - arn:aws:lambda:us-west-2:123456789012:function:my-function.
  • Partial ARN - 123456789012:function:my-function.
The length constraint applies only to the full ARN. If you specify only the function name, it is limited to 64 characters in length.

Parameter role : The Amazon Resource Name (ARN) of the function's execution role.

Parameter codeSigningConfigArn : To enable code signing for this function, specify the ARN of a code-signing configuration. A code-signing configuration includes a set of signing profiles, which define the trusted publishers for this function.

Parameter deadLetterConfig : A dead letter queue configuration that specifies the queue or topic where Lambda sends asynchronous events when they fail processing. For more information, see Dead Letter Queues.

Parameter description : A description of the function.

Parameter environment : Environment variables that are accessible from function code during execution.

Parameter fileSystemConfigs : Connection settings for an Amazon EFS file system.

Parameter handler : The name of the method within your code that Lambda calls to execute your function. The format includes the file name. It can also include namespaces and other qualifiers, depending on the runtime. For more information, see Programming Model.

Parameter imageConfig : Configuration values that override the container image Dockerfile.

Parameter kMSKeyArn : The ARN of the AWS Key Management Service (AWS KMS) key that's used to encrypt your function's environment variables. If it's not provided, AWS Lambda uses a default service key.

Parameter layers : A list of function layers to add to the function's execution environment. Specify each layer by its ARN, including the version.

Parameter memorySize : The amount of memory available to the function at runtime. Increasing the function's memory also increases its CPU allocation. The default value is 128 MB. The value can be any multiple of 1 MB.

Parameter packageType : The type of deployment package. Set to Image for container image and set Zip for ZIP archive.

Parameter publish : Set to true to publish the first version of the function during creation.

Parameter runtime : The identifier of the function's runtime.

Parameter tags : A list of tags to apply to the function.

Parameter timeout : The amount of time that Lambda allows a function to run before stopping it. The default is 3 seconds. The maximum allowed value is 900 seconds.

Parameter tracingConfig : Set Mode to Active to sample and trace a subset of incoming requests with AWS X-Ray.

Parameter vpcConfig : For network connectivity to AWS resources in a VPC, specify a list of security groups and subnets in the VPC. When you connect a function to a VPC, it can only access resources and the internet through that VPC. For more information, see VPC Settings.

Implementation

Future<FunctionConfiguration> createFunction({
  required FunctionCode code,
  required String functionName,
  required String role,
  String? codeSigningConfigArn,
  DeadLetterConfig? deadLetterConfig,
  String? description,
  Environment? environment,
  List<FileSystemConfig>? fileSystemConfigs,
  String? handler,
  ImageConfig? imageConfig,
  String? kMSKeyArn,
  List<String>? layers,
  int? memorySize,
  PackageType? packageType,
  bool? publish,
  Runtime? runtime,
  Map<String, String>? tags,
  int? timeout,
  TracingConfig? tracingConfig,
  VpcConfig? vpcConfig,
}) async {
  ArgumentError.checkNotNull(code, 'code');
  ArgumentError.checkNotNull(functionName, 'functionName');
  _s.validateStringLength(
    'functionName',
    functionName,
    1,
    140,
    isRequired: true,
  );
  ArgumentError.checkNotNull(role, 'role');
  _s.validateStringLength(
    'codeSigningConfigArn',
    codeSigningConfigArn,
    0,
    200,
  );
  _s.validateStringLength(
    'description',
    description,
    0,
    256,
  );
  _s.validateStringLength(
    'handler',
    handler,
    0,
    128,
  );
  _s.validateNumRange(
    'memorySize',
    memorySize,
    128,
    10240,
  );
  _s.validateNumRange(
    'timeout',
    timeout,
    1,
    1152921504606846976,
  );
  final $payload = <String, dynamic>{
    'Code': code,
    'FunctionName': functionName,
    'Role': role,
    if (codeSigningConfigArn != null)
      'CodeSigningConfigArn': codeSigningConfigArn,
    if (deadLetterConfig != null) 'DeadLetterConfig': deadLetterConfig,
    if (description != null) 'Description': description,
    if (environment != null) 'Environment': environment,
    if (fileSystemConfigs != null) 'FileSystemConfigs': fileSystemConfigs,
    if (handler != null) 'Handler': handler,
    if (imageConfig != null) 'ImageConfig': imageConfig,
    if (kMSKeyArn != null) 'KMSKeyArn': kMSKeyArn,
    if (layers != null) 'Layers': layers,
    if (memorySize != null) 'MemorySize': memorySize,
    if (packageType != null) 'PackageType': packageType.toValue(),
    if (publish != null) 'Publish': publish,
    if (runtime != null) 'Runtime': runtime.toValue(),
    if (tags != null) 'Tags': tags,
    if (timeout != null) 'Timeout': timeout,
    if (tracingConfig != null) 'TracingConfig': tracingConfig,
    if (vpcConfig != null) 'VpcConfig': vpcConfig,
  };
  final response = await _protocol.send(
    payload: $payload,
    method: 'POST',
    requestUri: '/2015-03-31/functions',
    exceptionFnMap: _exceptionFns,
  );
  return FunctionConfiguration.fromJson(response);
}