AWS Lambda

Lithops with AWS Lambda as serverless compute backend.

Installation

1. Install AWS backend dependencies:

python3 -m pip install lithops[aws]

Configuration

1. Login to Amazon Web Services Console (or signup if you don’t have an account)

2. Navigate to IAM > Policies. Click on Create policy.

3. Select JSON tab and paste the following JSON policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:*",
                "lambda:*",
                "ec2:*",
                "ecr:*",
                "sts:GetCallerIdentity",
                "logs:CreateLogGroup",
                "logs:CreateLogStream",
                "logs:PutLogEvents"
            ],
            "Resource": "*"
        }
    ]
}

4. Click Next: Tags and Next: Review. Fill the policy name field (you can name it lithops-policy or similar) and create the policy.

5. Go back to IAM and navigate to Roles tab. Click Create role.

6. Choose Lambda on the use case list and click Next: Permissions. Select the policy created before (lithops-policy). Click Next: Tags and Next: Review. Type a role name, for example lambdaLithopsExecutionRole. Click on Create Role.

AWS Credential setup

Lithops loads AWS credentials as specified in the boto3 configuration guide.

In summary, you can use one of the following settings:

1. Provide the credentials via the ~/.aws/config file, or set the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

   You can run aws configure command if the AWS CLI is installed to setup the credentials. Then set in the Lithops config file:

   lithops:
       backend: aws_lambda
   
   aws_lambda:
       execution_role: <EXECUTION_ROLE_ARN>
       region: <REGION_NAME>
   

2. Provide the credentials in the aws section of the Lithops config file:

   lithops:
       backend: aws_lambda
   
   aws:
       access_key_id: <AWS_ACCESS_KEY_ID>
       secret_access_key: <AWS_SECRET_ACCESS_KEY>
       region: <REGION_NAME>
   
   aws_lambda:
       execution_role: <EXECUTION_ROLE_ARN>
   

Summary of configuration keys for AWS

AWS

Group	Key	Default	Mandatory	Additional info
aws	region		yes	AWS Region. For example us-east-1
aws	access_key_id		no	Account access key to AWS services. To find them, navigate to My Security Credentials and click Create Access Key if you don’t already have one.
aws	secret_access_key		no	Account secret access key to AWS services. To find them, navigate to My Security Credentials and click Create Access Key if you don’t already have one.
aws	session_token		no	Session token for temporary AWS credentials
aws	account_id		no	*This field will be used if present to retrieve the account ID instead of using AWS STS. The account ID is used to format full image names for container runtimes.

AWS Lambda

Group	Key	Default	Mandatory	Additional info
aws_lambda	execution_role		yes	ARN of the execution role created at step 3. You can find it in the Role page at the Roles list in the IAM section (e.g. arn:aws:iam::1234567890:role/lambdaLithopsExecutionRole
aws_lambda	region		no	Region where Lambda functions will be invoked (e.g. us-east-1). Lithops will use the region set under the aws section if it is not set here
aws_lambda	max_workers	1000	no	Max number of workers per FunctionExecutor()
aws_lambda	worker_processes	1	no	Number of Lithops processes within a given worker. This can be used to parallelize function activations within a worker
aws_lambda	runtime		no	Docker image name
aws_lambda	runtime_memory	256	no	Memory limit in MB. Default 256MB
aws_lambda	runtime_timeout	180	no	Runtime timeout in seconds. Default 3 minutes
aws_lambda	invoke_pool_threads	64	no	Number of concurrent threads used for invocation
aws_lambda	remote_invoker	False	no	Activate the remote invoker feature that uses one cloud function to spawn all the actual map() activations
aws_lambda	architecture	x86_64	no	Runtime architecture. One of x86_64 or arm64
aws_lambda	ephemeral_storage	512	no	Ephemeral storage (/tmp) size in MB (must be between 512 MB and 10240 MB)
aws_lambda	user_tags	{}	no	List of {name: …, value: …} pairs for Lambda instance user tags
aws_lambda	env_vars	{}	no	List of {name: …, value: …} pairs for Lambda instance environment variables
aws_lambda	namespace		no	Virtual namespace. This can be useful to virtually group Lithops function workers. The functions deployed by lithops will be prefixed by this namespace. For example you can set it to differentiate between prod, dev and stage environments.
aws_lambda	runtime_include_function	False	no	If set to true, Lithops will automatically build a new runtime, including the function’s code, instead of transferring it through the storage backend at invocation time. This is useful when the function’s code size is large (in the order of 10s of MB) and the code does not change frequently

Additional configuration

VPC

To connect the Lithops lambda to a VPC, add the following configuration to the aws_lambda configuration section:

aws_lambda:
    execution_role: <EXECUTION_ROLE_ARN>
    region: <REGION_NAME>
    vpc:
        subnets:
            - <SUBNET_ID_1>
            - <SUBNET_ID_2>
            ...
        security_groups:
            - <SECURITY_GROUP_1>
            - <SECURITY_GROUP_2>
                ...

• subnets: A list of VPC subnet IDs.

• security_groups: A list of VPC security groups IDs.

Note: To be able to create network interfaces for Lambda functions, the role created in step 3 has to have permissions to do so, for example by adding the permission EC2FullAccess.

For more information, check out AWS documentation on VPCs.

EFS

To attach EFS volumes to the Lithops lambda, add the following configuration to the aws_lambda configuration section:

aws_lambda:
    execution_role: <EXECUTION_ROLE_ARN>
    region: <REGION_NAME>
    vpc:
        ...
    efs:
        - access_point: <EFS_ACCESS_POINT_1>
          mount_path: <LAMBDA_VOLUME_MOUNT_PATH_1>
        - access_point: <EFS_ACCESS_POINT_2>
          mount_path: <LAMBDA_VOLUME_MOUNT_PATH_2>
            ...

• access_point: The Amazon Resource Name (ARN) of the Amazon EFS access point that provides access to the file system.

• mount_path: The path where the function can access the file system. It must start with /mnt.

Note: to access those volumes, the Lithops lambda has to be connected to the same VPC and subnets as the EFS volumes are mounted to.

For more information, check out AWS documentation on attaching EFS volumes to Lambda.

Test Lithops

Once you have your compute and storage backends configured, you can run a hello world function with:

lithops hello -b aws_lambda -s aws_s3

Viewing the execution logs

You can view the function executions logs in your local machine using the lithops client:

lithops logs poll