Component: spacelift/worker-pool

This component is responsible for provisioning Spacelift worker pools.

By default, workers are given pull access to the configured ECR, permission to assume the spacelift team role in the identity account (although you must also configure the spacelift team in the identity account to allow the workers to assume the role via trusted_role_arns), and have the following AWS managed IAM policies attached:

• AmazonSSMManagedInstanceCore
• AutoScalingReadOnlyAccess
• AWSXRayDaemonWriteAccess
• CloudWatchAgentServerPolicy

Among other things, this allows workers with SSM agent installed to be accessed via SSM Session Manager.

aws ssm start-session --target <instance-id>

Usage

Stack Level: Regional

Here's an example snippet for how to use this component.

# stacks/catalog/spacelift/worker-pool.yaml
components:
  terraform:
    spacelift/worker-pool:
      settings:
        spacelift:
          administrative: true
          space_name: root
      vars:
        enabled: true
        spacelift_api_endpoint: https://<GITHUBORG>.app.spacelift.io
        spacelift_spaces_tenant_name: "acme"
        spacelift_spaces_environment_name: "gbl"
        spacelift_spaces_stage_name: "root"
        account_map_tenant_name: core
        ecr_environment_name: ue1
        ecr_repo_name: infrastructure
        ecr_stage_name: artifacts
        ecr_tenant_name: core
        # Set a low scaling threshold to ensure new workers are launched as soon as the current one(s) are busy
        cpu_utilization_high_threshold_percent: 10
        cpu_utilization_low_threshold_percent: 5
        default_cooldown: 300
        desired_capacity: null
        health_check_grace_period: 300
        health_check_type: EC2
        infracost_enabled: true
        instance_type: t3.small
        max_size: 3
        min_size: 1
        name: spacelift-worker-pool
        scale_down_cooldown_seconds: 2700
        spacelift_agents_per_node: 1
        wait_for_capacity_timeout: 5m
        block_device_mappings:
          - device_name: "/dev/xvda"
            no_device: null
            virtual_name: null
            ebs:
              delete_on_termination: null
              encrypted: false
              iops: null
              kms_key_id: null
              snapshot_id: null
              volume_size: 100
              volume_type: "gp2"

Impacts on billing

While scaling the workload for Spacelift, keep in mind that each agent connection counts against your quota of self-hosted workers. The number of EC2 instances you have running is not going to affect your Spacelift bill. As an example, if you had 3 EC2 instances in your Spacelift worker pool, and you configured spacelift_agents_per_node to be 3, you would see your Spacelift bill report 9 agents being run. Take care while configuring the worker pool for your Spacelift infrastructure.

Configuration

Docker Image on ECR

Build and tag a Docker image for this repository and push to ECR. Ensure the account where this component is deployed has read-only access to the ECR repository.

API Key

Prior to deployment, the API key must exist in SSM. The key must have admin permissions.

To generate the key, please follow these instructions. Once generated, write the API key ID and secret to the SSM key store at the following locations within the same AWS account and region where the Spacelift worker pool will reside.

Key	SSM Path	Type
API ID	/spacelift/key_id	SecureString
API Key	/spacelift/key_secret	SecureString

HINT: The API key ID is displayed as an upper-case, 16-character alphanumeric value next to the key name in the API key list.

Save the keys using chamber using the correct profile for where Spacelift worker pool is provisioned

AWS_PROFILE=acme-gbl-auto-admin chamber write spacelift key_id 1234567890123456
AWS_PROFILE=acme-gbl-auto-admin chamber write spacelift key_secret abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz

IAM configuration

After provisioning the component, you must give the created instance role permission to assume the Spacelift worker role. This is done by adding iam_role_arn from the output to the trusted_role_arns list for the spacelift role in aws-teams.

Requirements

Name	Version
terraform	>= 1.0.0
aws	>= 4.9.0
cloudinit	>= 2.2.0
spacelift	>= 0.1.2

Providers

Name	Version
aws	>= 4.9.0
cloudinit	>= 2.2.0
spacelift	>= 0.1.2

Modules

Name	Source	Version
account_map	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
autoscale_group	cloudposse/ec2-autoscale-group/aws	0.35.1
ecr	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
iam_label	cloudposse/label/null	0.25.0
iam_roles	../../account-map/modules/iam-roles	n/a
security_group	cloudposse/security-group/aws	2.2.0
spaces	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
this	cloudposse/label/null	0.25.0
vpc	cloudposse/stack-config/yaml//modules/remote-state	1.5.0

Resources

Name	Type
aws_iam_instance_profile.default	resource
aws_iam_policy.default	resource
aws_iam_role.default	resource
spacelift_worker_pool.primary	resource
aws_ami.spacelift	data source
aws_iam_policy_document.assume_role_policy	data source
aws_iam_policy_document.default	data source
aws_partition.current	data source
aws_ssm_parameter.spacelift_key_id	data source
aws_ssm_parameter.spacelift_key_secret	data source
cloudinit_config.config	data source

Inputs

Name	Description	Type	Default	Required
account_map_environment_name	The name of the environment where account_map is provisioned	string	"gbl"	no
account_map_stage_name	The name of the stage where account_map is provisioned	string	"root"	no
account_map_tenant_name	The name of the tenant where account_map is provisioned. If the tenant label is not used, leave this as null.	string	null	no
additional_tag_map	Additional key-value pairs to add to each map in tags_as_list_of_maps. Not added to tags or id. This is for some rare cases where resources want additional configuration of tags and therefore take a list of maps with tag key, value, and additional configuration.	map(string)	{}	no
attributes	ID element. Additional attributes (e.g. workers or cluster) to add to id, in the order they appear in the list. New attributes are appended to the end of the list. The elements of the list are joined by the delimiter and treated as a single ID element.	list(string)	[]	no
aws_config_file	The AWS_CONFIG_FILE used by the worker. Can be overridden by /.spacelift/config.yml.	string	"/etc/aws-config/aws-config-spacelift"	no
aws_profile	The AWS_PROFILE used by the worker. If not specified, "${var.namespace}-identity" will be used. Can be overridden by /.spacelift/config.yml.	string	null	no
block_device_mappings	Specify volumes to attach to the instance besides the volumes specified by the AMI	list(object({ device_name = string no_device = bool virtual_name = string ebs = object({ delete_on_termination = bool encrypted = bool iops = number kms_key_id = string snapshot_id = string volume_size = number volume_type = string }) }))	[]	no
context	Single object for setting entire context at once. See description of individual variables for details. Leave string and numeric variables as null to use default value. Individual variable settings (non-null) override settings in context object, except for attributes, tags, and additional_tag_map, which are merged.	any	{ "additional_tag_map": {}, "attributes": [], "delimiter": null, "descriptor_formats": {}, "enabled": true, "environment": null, "id_length_limit": null, "label_key_case": null, "label_order": [], "label_value_case": null, "labels_as_tags": [ "unset" ], "name": null, "namespace": null, "regex_replace_chars": null, "stage": null, "tags": {}, "tenant": null }	no
cpu_utilization_high_threshold_percent	CPU utilization high threshold	number	n/a	yes
cpu_utilization_low_threshold_percent	CPU utilization low threshold	number	n/a	yes
custom_spacelift_ami	Custom spacelift AMI	bool	false	no
default_cooldown	The amount of time, in seconds, after a scaling activity completes before another scaling activity can start	number	300	no
delimiter	Delimiter to be used between ID elements. Defaults to - (hyphen). Set to "" to use no delimiter at all.	string	null	no
descriptor_formats	Describe additional descriptors to be output in the descriptors output map. Map of maps. Keys are names of descriptors. Values are maps of the form {<br/> format = string<br/> labels = list(string)<br/>} (Type is any so the map values can later be enhanced to provide additional options.) format is a Terraform format string to be passed to the format() function. labels is a list of labels, in order, to pass to format() function. Label values will be normalized before being passed to format() so they will be identical to how they appear in id. Default is {} (descriptors output will be empty).	any	{}	no
desired_capacity	The number of Amazon EC2 instances that should be running in the group, if not set will use min_size as value	number	null	no
ebs_optimized	If true, the launched EC2 instance will be EBS-optimized	bool	false	no
ecr_environment_name	The name of the environment where ecr is provisioned	string	""	no
ecr_region	AWS region that contains the ECR infrastructure repo	string	""	no
ecr_repo_name	ECR repository name	string	n/a	yes
ecr_stage_name	The name of the stage where ecr is provisioned	string	"artifacts"	no
ecr_tenant_name	The name of the tenant where ecr is provisioned. If the tenant label is not used, leave this as null.	string	null	no
enabled	Set to false to prevent the module from creating any resources	bool	null	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	string	null	no
github_netrc_enabled	Whether to create a GitHub .netrc file so Spacelift can clone private GitHub repositories.	bool	false	no
github_netrc_ssm_path_token	If github_netrc is enabled, this is the SSM path to retrieve the GitHub token.	string	"/github/token"	no
github_netrc_ssm_path_user	If github_netrc is enabled, this is the SSM path to retrieve the GitHub user	string	"/github/user"	no
health_check_grace_period	Time (in seconds) after instance comes into service before checking health	number	300	no
health_check_type	Controls how health checking is done. Valid values are EC2 or ELB	string	"EC2"	no
iam_attributes	Additional attributes to add to the IDs of the IAM role and policy	list(string)	[]	no
id_length_limit	Limit id to this many characters (minimum 6). Set to 0 for unlimited length. Set to null for keep the existing setting, which defaults to 0. Does not affect id_full.	number	null	no
infracost_api_token_ssm_path	This is the SSM path to retrieve and set the INFRACOST_API_TOKEN environment variable	string	"/infracost/token"	no
infracost_cli_args	These are the CLI args passed to infracost	string	""	no
infracost_enabled	Whether to enable infracost for Spacelift stacks	bool	false	no
infracost_warn_on_failure	A failure executing Infracost, or a non-zero exit code being returned from the command will cause runs to fail. If this is true, this will only warn instead of failing the stack.	bool	true	no
instance_refresh	The instance refresh definition. If this block is configured, an Instance Refresh will be started when the Auto Scaling Group is updated	object({ strategy = string preferences = object({ instance_warmup = optional(number, null) min_healthy_percentage = optional(number, null) skip_matching = optional(bool, null) auto_rollback = optional(bool, null) }) triggers = optional(list(string), []) })	null	no
instance_type	EC2 instance type to use for workers	string	"r5n.large"	no
label_key_case	Controls the letter case of the tags keys (label names) for tags generated by this module. Does not affect keys of tags passed in via the tags input. Possible values: lower, title, upper. Default value: title.	string	null	no
label_order	The order in which the labels (ID elements) appear in the id. Defaults to ["namespace", "environment", "stage", "name", "attributes"]. You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.	list(string)	null	no
label_value_case	Controls the letter case of ID elements (labels) as included in id, set as tag values, and output by this module individually. Does not affect values of tags passed in via the tags input. Possible values: lower, title, upper and none (no transformation). Set this to title and set delimiter to "" to yield Pascal Case IDs. Default value: lower.	string	null	no
labels_as_tags	Set of labels (ID elements) to include as tags in the tags output. Default is to include all labels. Tags with empty values will not be included in the tags output. Set to [] to suppress all generated tags. Notes: The value of the name tag, if included, will be the id, not the name. Unlike other null-label inputs, the initial setting of labels_as_tags cannot be changed in later chained modules. Attempts to change it will be silently ignored.	set(string)	[ "default" ]	no
launch_template_version	Launch template version to use for workers	string	"$Latest"	no
max_size	The maximum size of the autoscale group	number	n/a	yes
min_size	The minimum size of the autoscale group	number	n/a	yes
mixed_instances_policy	Policy to use a mixed group of on-demand/spot of different types. Launch template is automatically generated. https://www.terraform.io/docs/providers/aws/r/autoscaling_group.html#mixed_instances_policy-1	object({ instances_distribution = object({ on_demand_allocation_strategy = string on_demand_base_capacity = number on_demand_percentage_above_base_capacity = number spot_allocation_strategy = string spot_instance_pools = number spot_max_price = string }) override = list(object({ instance_type = string weighted_capacity = number })) })	null	no
name	ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'. This is the only ID element not also included as a tag. The "name" tag is set to the full id string. There is no tag with the value of the name input.	string	null	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	string	null	no
regex_replace_chars	Terraform regular expression (regex) string. Characters matching the regex will be removed from the ID elements. If not set, "/[^a-zA-Z0-9-]/" is used to remove all characters other than hyphens, letters and digits.	string	null	no
region	AWS Region	string	n/a	yes
scale_down_cooldown_seconds	The amount of time, in seconds, after a scaling activity completes and before the next scaling activity can start	number	300	no
space_name	The name of the Space to create the worker pool in	string	"root"	no
spacelift_agents_per_node	Number of Spacelift agents to run on one worker node. NOTE: This affects billable units. Spacelift charges per agent.	number	1	no
spacelift_ami_id	AMI ID of Spacelift worker pool image	string	null	no
spacelift_api_endpoint	The Spacelift API endpoint URL (e.g. https://example.app.spacelift.io)	string	n/a	yes
spacelift_aws_account_id	AWS Account ID owned by Spacelift	string	"643313122712"	no
spacelift_domain_name	Top-level domain name to use for pulling the launcher binary	string	"spacelift.io"	no
spacelift_runner_image	URL of ECR image to use for Spacelift	string	""	no
spacelift_spaces_component_name	The name of the spacelift spaces component	string	"spacelift/spaces"	no
spacelift_spaces_environment_name	The environment name of the spacelift spaces component	string	null	no
spacelift_spaces_stage_name	The stage name of the spacelift spaces component	string	null	no
spacelift_spaces_tenant_name	The tenant name of the spacelift spaces component	string	null	no
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	string	null	no
tags	Additional tags (e.g. {'BusinessUnit': 'XYZ'}). Neither the tag keys nor the tag values will be modified by this module.	map(string)	{}	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	string	null	no
termination_policies	A list of policies to decide how the instances in the auto scale group should be terminated. The allowed values are OldestInstance, NewestInstance, OldestLaunchConfiguration, ClosestToNextInstanceHour, Default	list(string)	[ "OldestLaunchConfiguration" ]	no
wait_for_capacity_timeout	A maximum duration that Terraform should wait for ASG instances to be healthy before timing out. (See also Waiting for Capacity below.) Setting this to '0' causes Terraform to skip all Capacity Waiting behavior	string	n/a	yes

Outputs

Name	Description
autoscaling_group_arn	The ARN for this AutoScaling Group
autoscaling_group_default_cooldown	Time between a scaling activity and the succeeding scaling activity
autoscaling_group_health_check_grace_period	Time after instance comes into service before checking health
autoscaling_group_health_check_type	EC2 or ELB. Controls how health checking is done
autoscaling_group_id	The autoscaling group id
autoscaling_group_max_size	The maximum size of the autoscale group
autoscaling_group_min_size	The minimum size of the autoscale group
autoscaling_group_name	The autoscaling group name
iam_role_arn	Spacelift IAM Role ARN
iam_role_id	Spacelift IAM Role ID
iam_role_name	Spacelift IAM Role name
launch_template_arn	The ARN of the launch template
launch_template_id	The ID of the launch template
security_group_arn	Spacelift Security Group ARN
security_group_id	Spacelift Security Group ID
security_group_name	Spacelift Security Group Name
worker_pool_id	Spacelift worker pool ID
worker_pool_name	Spacelift worker pool name

References

• cloudposse/terraform-spacelift-cloud-infrastructure-automation - Cloud Posse's related upstream component
• cloudposse/terraform-aws-components - Cloud Posse's upstream component