AWS Elastic Compute Cloud (EC2)

The AWS EC2 client of Lithops can provide a truely serverless user experience on top of EC2 where Lithops creates new Virtual Machines (VMs) dynamically in runtime and scale Lithops jobs against them. Alternatively Lithops can start and stop an existing VM instances.

AWS

The assumption that you already familiar with AWS, and you have AUTH credentials to your account (HMAC Credentials).

Choose an operating system image for the VM

Any Virtual Machine (VM) need to define the instance’s operating system and version. Lithops support both standard operating system choices provided by the VPC or using pre-defined custom images that already contains all dependencies required by Lithops.

• Option 1: By default, Lithops uses an Ubuntu 22.04 image. In this case, no further action is required and you can continue to the next step. Lithops will install all required dependencies in the VM by itself. Notice this can consume about 3 min to complete all installations.

• Option 2: Alternatively, you can use a pre-built custom image that will greatly improve VM creation time for Lithops jobs. To benefit from this approach, navigate to runtime/aws_ec2, and follow the instructions.

Lithops and the VM consume mode

In this mode, Lithops can start and stop an existing VM, and deploy an entire job to that VM. The partition logic in this scenario is different from the create/reuse modes, since the entire job is executed in the same VM.

Lithops configuration for the consume mode

Edit your lithops config and add the relevant keys:

lithops:
    backend: aws_ec2

aws:
    region : <REGION_NAME>
    access_key_id: <AWS_ACCESS_KEY_ID>
    secret_access_key: <AWS_SECRET_ACCESS_KEY>

aws_ec2:
    exec_mode: consume
    instance_id : <INSTANCE ID OF THE VM>

Summary of configuration keys for AWS

Group	Key	Default	Mandatory	Additional info
aws	region		yes	AWS Region. For example us-east-1
aws	access_key_id		yes	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		yes	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.

EC2 - Consume Mode

Group	Key	Default	Mandatory	Additional info
aws_ec2	instance_id		yes	virtual server instance ID
aws_ec2	region		no	Region name of the VPC. For example us-east-1. Lithops will use the region set under the aws section if it is not set here
aws_ec2	ssh_username	ubuntu	no	Username to access the VM
aws_ec2	ssh_key_filename	~/.ssh/id_rsa	no	Path to the ssh key file provided to create the VM. It will use the default path if not provided
aws_ec2	worker_processes	AUTO	no	Number of Lithops processes within a given worker. This is used to parallelize function activations within the worker. By default it detects the amount of CPUs in the VM
aws_ec2	runtime	python3	no	Runtime name to run the functions. Can be a container image name. If not set Lithops will use the defeuv python3 interpreter of the VM
aws_ec2	auto_dismantle	True	no	If False then the VM is not stopped automatically.
aws_ec2	soft_dismantle_timeout	300	no	Time in seconds to stop the VM instance after a job completed its execution
aws_ec2	hard_dismantle_timeout	3600	no	Time in seconds to stop the VM instance after a job started its execution

Lithops and the VM auto create|reuse mode

In the create mode, Lithops will automatically create new worker VM instances in runtime, scale Lithops job against generated VMs, and automatically delete the VMs when the job is completed. Alternatively, you can set the reuse mode to keep running the started worker VMs, and reuse them for further executions. In the reuse mode, Lithops checks all the available worker VMs and start new workers only if necessary.

Lithops configuration for the auto create mode

Edit your lithops config and add the relevant keys:

lithops:
    backend: aws_ec2

aws:
    access_key_id: <AWS_ACCESS_KEY_ID>
    secret_access_key: <AWS_SECRET_ACCESS_KEY>
    region: <REGION_NAME>

aws_ec2:
    iam_role: <IAM_ROLE_NAME>
    exec_mode: reuse

Summary of configuration keys for AWS

Group	Key	Default	Mandatory	Additional info
aws	region		yes	AWS Region. For example us-east-1
aws	access_key_id		yes	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		yes	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.

EC2 - Create and Reuse Modes

Group	Key	Default	Mandatory	Additional info
aws_ec2	region		yes	Region name, for example: eu-west-1. Lithops will use the region set under the aws section if it is not set here
aws_ec2	iam_role		yes	IAM EC2 role name. You can find it in the IAM Console page. Create a new EC2 role if it does not exist
aws_ec2	vpc_id		no	VPC id. You can find all the available VPCs in the VPC Console page
aws_ec2	subnet_id		no	Subnet id. You can find all the available Subnets in the VPC Console page
aws_ec2	security_group_id		no	Security group ID. You can find the available security groups in the VPC console page. The security group must have ports 22 and 8080 open
aws_ec2	ssh_key_name		no	SSH Key name. You can find the available keys in the EC2 console page. Create a new one or upload your own key if it does not exist
aws_ec2	ssh_username	ubuntu	no	Username to access the VM
aws_ec2	ssh_password		no	Password for accessing the worker VMs. If not provided, it is created randomly
aws_ec2	ssh_key_filename	~/.ssh/id_rsa	no	Path to the ssh key file provided to access the VPC. It will use the default path if not provided
aws_ec2	request_spot_instances	True	no	Request spot instance for worker VMs
aws_ec2	target_ami		no	Virtual machine image id. Default is Ubuntu Server 20.04
aws_ec2	master_instance_type	t2.micro	no	Profile name for the master VM
aws_ec2	worker_instance_type	t2.medium	no	Profile name for the worker VMs
aws_ec2	delete_on_dismantle	True	no	Delete the worker VMs when they are stopped. Master VM is never deleted when stopped
aws_ec2	max_workers	100	no	Max number of workers per FunctionExecutor()
aws_ec2	worker_processes	2	no	Number of Lithops processes within a given worker. This can be used to parallelize function activations within a worker. It is recommendable to set this value to the same number of CPUs of a worker VM.
aws_ec2	runtime	python3	no	Runtime name to run the functions. Can be a container image name. If not set Lithops will use the default python3 interpreter of the VM
aws_ec2	auto_dismantle	True	no	If False then the VM is not stopped automatically.
aws_ec2	soft_dismantle_timeout	300	no	Time in seconds to stop the VM instance after a job completed its execution
aws_ec2	hard_dismantle_timeout	3600	no	Time in seconds to stop the VM instance after a job started its execution
aws_ec2	exec_mode	reuse	no	One of: consume, create or reuse. If set to create, Lithops will automatically create new VMs for each map() call based on the number of elements in iterdata. If set to reuse will try to reuse running workers if exist
aws_ec2	pull_runtime	False	no	If set to True, Lithops will execute the command docker pull <runtime_name> in each VSI before executing the a job (in case of using a docker runtime)
aws_ec2	workers_policy	permissive	no	One of: permissive, strict. If set to strict will force creation of required workers number

Test Lithops

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

lithops hello -b aws_ec2 -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

The master and worker VMs contain the Lithops service logs in /tmp/lithops-root/service.log

You can login to the master VM and get a live ssh connection with:

lithops attach -b aws_ec2