worker-pool-asg

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.

Variables

Required Variables

cpu_utilization_high_threshold_percent (number) required: CPU utilization high threshold
cpu_utilization_low_threshold_percent (number) required: CPU utilization low threshold
ecr_repo_name (string) required: ECR repository name
max_size (number) required: The maximum size of the autoscale group
min_size (number) required: The minimum size of the autoscale group
region (string) required: AWS Region
spacelift_api_endpoint (string) required: The Spacelift API endpoint URL (e.g. https://example.app.spacelift.io)
wait_for_capacity_timeout (string) required: 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

Optional Variables

account_map_environment_name (string) optional

The name of the environment where account_map is provisioned

Default value: "gbl"

account_map_stage_name (string) optional

The name of the stage where account_map is provisioned

Default value: "root"

account_map_tenant_name (string) optional

The name of the tenant where account_map is provisioned.

If the tenant label is not used, leave this as null.

Default value: null

architecture (list(string)) optional

OS architecture of the EC2 instance AMI

Default value:

[
  "x86_64"
]

aws_config_file (string) optional

The AWS_CONFIG_FILE used by the worker. Can be overridden by /.spacelift/config.yml.

Default value: "/etc/aws-config/aws-config-spacelift"

aws_profile (string) optional

The AWS_PROFILE used by the worker. If not specified, "${var.namespace}-identity" will be used.
Can be overridden by /.spacelift/config.yml.

Default value: null

block_device_mappings optional

Specify volumes to attach to the instance besides the volumes specified by the AMI

Type:

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
})
}))

Default value: [ ]

custom_spacelift_ami (bool) optional

Custom spacelift AMI

Default value: false

default_cooldown (number) optional

The amount of time, in seconds, after a scaling activity completes before another scaling activity can start

Default value: 300

desired_capacity (number) optional

The number of Amazon EC2 instances that should be running in the group, if not set will use min_size as value

Default value: null

ebs_optimized (bool) optional

If true, the launched EC2 instance will be EBS-optimized

Default value: false

ecr_environment_name (string) optional

The name of the environment where ecr is provisioned

Default value: ""

ecr_region (string) optional

AWS region that contains the ECR infrastructure repo

Default value: ""

ecr_stage_name (string) optional

The name of the stage where ecr is provisioned

Default value: "artifacts"

ecr_tenant_name (string) optional

The name of the tenant where ecr is provisioned.

If the tenant label is not used, leave this as null.

Default value: null

github_netrc_enabled (bool) optional

Whether to create a GitHub .netrc file so Spacelift can clone private GitHub repositories.

Default value: false

github_netrc_ssm_path_token (string) optional

If github_netrc is enabled, this is the SSM path to retrieve the GitHub token.

Default value: "/github/token"

github_netrc_ssm_path_user (string) optional

If github_netrc is enabled, this is the SSM path to retrieve the GitHub user

Default value: "/github/user"

health_check_grace_period (number) optional

Time (in seconds) after instance comes into service before checking health

Default value: 300

health_check_type (string) optional

Controls how health checking is done. Valid values are EC2 or ELB

Default value: "EC2"

iam_attributes (list(string)) optional

Additional attributes to add to the IDs of the IAM role and policy

Default value: [ ]

infracost_api_token_ssm_path (string) optional

This is the SSM path to retrieve and set the INFRACOST_API_TOKEN environment variable

Default value: "/infracost/token"

infracost_cli_args (string) optional

These are the CLI args passed to infracost

Default value: ""

infracost_enabled (bool) optional

Whether to enable infracost for Spacelift stacks

Default value: false

infracost_warn_on_failure (bool) optional

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.

Default value: true

instance_lifetime (number) optional

Number of seconds after which the instance will be terminated. The default is set to 14 days.

Default value: 1209600

instance_refresh optional

The instance refresh definition. If this block is configured, an Instance Refresh will be started when the Auto Scaling Group is updated

Type:

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), [])
})

Default value: null

instance_type (string) optional

EC2 instance type to use for workers

Default value: "r5n.large"

launch_template_version (string) optional

Launch template version to use for workers. Note that instance refresh settings are IGNORED unless template version is empty

Default value: "$Latest"

mixed_instances_policy optional

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

Type:

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
}))
})

Default value: null

scale_down_cooldown_seconds (number) optional

The amount of time, in seconds, after a scaling activity completes and before the next scaling activity can start

Default value: 300

space_name (string) optional

The name of the Space to create the worker pool in

Default value: "root"

spacelift_agents_per_node (number) optional

Number of Spacelift agents to run on one worker node. NOTE: This affects billable units. Spacelift charges per agent.

Default value: 1

spacelift_ami_id (string) optional

AMI ID of Spacelift worker pool image

Default value: null

spacelift_aws_account_id (string) optional

AWS Account ID owned by Spacelift

Default value: "643313122712"

spacelift_domain_name (string) optional

Top-level domain name to use for pulling the launcher binary

Default value: "spacelift.io"

spacelift_runner_image (string) optional

URL of ECR image to use for Spacelift

Default value: ""

spacelift_spaces_component_name (string) optional

The name of the spacelift spaces component

Default value: "spacelift/spaces"

spacelift_spaces_environment_name (string) optional

The environment name of the spacelift spaces component

Default value: null

spacelift_spaces_stage_name (string) optional

The stage name of the spacelift spaces component

Default value: null

spacelift_spaces_tenant_name (string) optional

The tenant name of the spacelift spaces component

Default value: null

termination_policies (list(string)) optional

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

Default value:

[
  "OldestLaunchConfiguration"
]

Context Variables

The following variables are defined in the context.tf file of this module and part of the terraform-null-label pattern.

additional_tag_map (map(string)) optional

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.

Required: No

Default value: { }

attributes (list(string)) optional

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.

Required: No

Default value: [ ]

context (any) optional

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.

Required: No

Default value:

{
  "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
}

delimiter (string) optional

Delimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.

Required: No

Default value: null

descriptor_formats (any) optional

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).

Required: No

Default value: { }

enabled (bool) optional

Set to false to prevent the module from creating any resources
Required: No

Default value: null

environment (string) optional

ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'
Required: No

Default value: null

id_length_limit (number) optional

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.

Required: No

Default value: null

label_key_case (string) optional

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.

Required: No

Default value: null

label_order (list(string)) optional

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.

Required: No

Default value: null

label_value_case (string) optional

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.

Required: No

Default value: null

labels_as_tags (set(string)) optional

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.

Required: No

Default value:

[
  "default"
]

name (string) optional

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.

Required: No

Default value: null

namespace (string) optional

ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique
Required: No

Default value: null

regex_replace_chars (string) optional

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.

Required: No

Default value: null

stage (string) optional

ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'
Required: No

Default value: null

tags (map(string)) optional

Additional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.

Required: No

Default value: { }

tenant (string) optional

ID element (Rarely used, not included by default). A customer identifier, indicating who this instance of a resource is for
Required: No

Default value: null

Outputs

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

Dependencies

Requirements

terraform, version: >= 1.0.0
aws, version: >= 4.9.0
cloudinit, version: >= 2.2.0
spacelift, version: >= 0.1.2

Providers

aws, version: >= 4.9.0
cloudinit, version: >= 2.2.0
spacelift, version: >= 0.1.2

Modules

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

Resources

The following resources are used by this module:

aws_iam_instance_profile.default (resource)
aws_iam_policy.default (resource)
aws_iam_role.default (resource)
spacelift_worker_pool.primary (resource)

Data Sources

The following data sources are used by this module:

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)

References

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

Usage​

Impacts on billing​

Configuration​

Docker Image on ECR​

API Key​

IAM configuration​

Variables​

Required Variables​

Optional Variables​

Context Variables​

Outputs​

Dependencies​

Requirements​

Providers​

Modules​

Resources​

Data Sources​

References​

Usage

Impacts on billing

Configuration

Docker Image on ECR

API Key

IAM configuration

Variables

Required Variables

Optional Variables

Context Variables

Outputs

Dependencies

Requirements

Providers

Modules

Resources

Data Sources

References