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Module: step-functions

Terraform module to provision AWS Step Functions.

Usage​

For a complete example, see examples/complete

For automated tests of the complete example using bats and Terratest (which tests and deploys the example on AWS), see test.

  locals {
    enabled = module.this.enabled

    logging_configuration = {
      include_execution_data = true
      level                  = "ALL"
    }

    # https://docs.aws.amazon.com/step-functions/latest/dg/concepts-amazon-states-language.html
    # https://docs.aws.amazon.com/step-functions/latest/dg/connect-parameters.html
    definition = {
      "Comment" = "Test Step Function"
      "StartAt" = "Hello"
      "States" = {
        "Hello" = {
          "Type"   = "Pass"
          "Result" = "Hello"
          "Next"   = "World"
        },
        "World" = {
          "Type"   = "Pass"
          "Result" = "World"
          "Next"   = "Send message to SQS"
        },
        # https://docs.aws.amazon.com/step-functions/latest/dg/connect-sqs.html
        "Send message to SQS" = {
          "Type"     = "Task"
          "Resource" = "arn:aws:states:::sqs:sendMessage"
          "Parameters" = {
            "QueueUrl"    = local.enabled ? aws_sqs_queue.default[0].url : ""
            "MessageBody" = "Hello World"
          }
          "Next" = "Publish to SNS"
        }
        # https://docs.aws.amazon.com/step-functions/latest/dg/connect-sns.html
        "Publish to SNS" = {
          "Type"     = "Task",
          "Resource" = "arn:aws:states:::sns:publish"
          "Parameters" = {
            "TopicArn" = module.sns.sns_topic_arn
            "Message"  = "Hello World"
          }
          "End" = true
        }
      }
    }

    iam_policies = {
      # https://docs.aws.amazon.com/step-functions/latest/dg/sns-iam.html
      "SnsAllowPublish" = {
        effect = "Allow"
        actions = [
          "sns:Publish"
        ]
        resources = [
          module.sns.sns_topic_arn
        ]
      }

      # https://docs.aws.amazon.com/step-functions/latest/dg/sqs-iam.html
      "SqsAllowSendMessage" = {
        effect = "Allow"
        actions = [
          "sqs:SendMessage"
        ]
        resources = [
          local.enabled ? aws_sqs_queue.default[0].arn : ""
        ]
      }
    }
  }

  module "step_function" {
    source = "cloudposse/step-functions/aws"
    # Cloud Posse recommends pinning every module to a specific version
    version = "x.x.x"

    type                                   = "EXPRESS"
    tracing_enabled                        = true
    logging_configuration                  = local.logging_configuration
    definition                             = local.definition
    iam_policies                           = local.iam_policies

    context = module.this.context
  }

  module "sns" {
    source  = "cloudposse/sns-topic/aws"
    version = "0.20.2"

    sqs_dlq_enabled    = true
    fifo_topic         = true
    fifo_queue_enabled = true

    context = module.this.context
  }

  resource "aws_sqs_queue" "default" {
    count = local.enabled ? 1 : 0

    name                       = module.this.id
    fifo_queue                 = false
    visibility_timeout_seconds = 30
    message_retention_seconds  = 86400
    max_message_size           = 2048
    delay_seconds              = 90
    receive_wait_time_seconds  = 10

    tags = module.this.tags
  }

Variables​

Required Variables​

definition (any) required

The Amazon States Language definition for the Step Function. Refer to https://docs.aws.amazon.com/step-functions/latest/dg/concepts-amazon-states-language.html for more details

Optional Variables​

cloudwatch_log_group_kms_key_id (string) optional

The ARN of the KMS Key to use when encrypting log data


Default value: null

cloudwatch_log_group_name (string) optional

Name of Cloudwatch Logs Group to use. If not provided, a name will be generated from the context


Default value: null

cloudwatch_log_group_retention_in_days (number) optional

Specifies the number of days to retain log events in the Log Group. Possible values are: 1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1827, and 3653


Default value: null

existing_aws_cloudwatch_log_group_arn (string) optional

The Amazon Resource Name (ARN) of the existing CloudWatch Log Group to use for the Step Function. If not provided, a new CloudWatch Log Group will be created


Default value: null

existing_iam_role_arn (string) optional

The Amazon Resource Name (ARN) of the existing IAM role to use for the Step Function. If not provided, a new IAM role will be created


Default value: null

iam_policies optional

IAM policies to attach to the created IAM role for the Step Function. The map keys will be used as the policy SIDs


Type:

map(object({
effect        = string
actions       = optional(list(string))
not_actions   = optional(list(string))
resources     = optional(list(string))
not_resources = optional(list(string))
principals = optional(list(object({
  type        = string
  identifiers = list(string)
})))
not_principals = optional(list(object({
  type        = string
  identifiers = list(string)
})))
condition = optional(list(object({
  test     = string
  variable = string
  values   = list(string)
})))
}))

Default value: { }

logging_configuration optional

Defines what execution history events are logged and where they are logged


Type:

object({
log_destination        = optional(string)
include_execution_data = bool
level                  = string
})

Default value:

{
  "include_execution_data": false,
  "level": "OFF"
}
role_description (string) optional

Description of the created IAM role


Default value: null

role_force_detach_policies (bool) optional

Specifies to force detaching any policies the created IAM role has before destroying it


Default value: true

role_name (string) optional

Name of the created IAM role. If not provided, a name will be generated from the context


Default value: null

role_path (string) optional

Path of the created IAM role


Default value: null

role_permissions_boundary (string) optional

The ARN of the policy that is used to set the permissions boundary for the created IAM role


Default value: null

step_function_name (string) optional

The name of the Step Function. If not provided, a name will be generated from the context


Default value: null

tracing_enabled (bool) optional

When set to true, AWS X-Ray tracing is enabled. Make sure the State Machine has the correct IAM policies for logging


Default value: false

type (string) optional

Determines whether a Standard or Express state machine is created. The default is STANDARD. Valid Values: STANDARD, EXPRESS


Default value: "STANDARD"

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​

role_arn

The ARN of the IAM role created for the Step Function

role_name

The name of the IAM role created for the Step Function

state_machine_arn

State machine ARN

state_machine_creation_date

State machine creation date

state_machine_id

State machine ID

state_machine_status

State machine status

Dependencies​

Requirements​

  • terraform, version: >= 1.3.0
  • aws, version: >= 4.0

Providers​

  • aws, version: >= 4.0

Modules​

NameVersionSourceDescription
logs_label0.25.0cloudposse/label/nulln/a
this0.25.0cloudposse/label/nulln/a

Resources​

The following resources are used by this module:

Data Sources​

The following data sources are used by this module: