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Module: s3-bucket

This module creates an S3 bucket with support for versioning, lifecycles, object locks, replication, encryption, ACL, bucket object policies, and static website hosting.

For backward compatibility, it sets the S3 bucket ACL to private and the s3_object_ownership to ObjectWriter. Moving forward, setting s3_object_ownership to BucketOwnerEnforced is recommended, and doing so automatically disables the ACL.

This module blocks public access to the bucket by default. See block_public_acls, block_public_policy, ignore_public_acls, and restrict_public_buckets to change the settings. See AWS documentation for more details.

This module can optionally create an IAM User with access to the S3 bucket. This is inherently insecure in that to enable anyone to become the User, access keys must be generated, and anything generated by Terraform is stored unencrypted in the Terraform state. See the Terraform documentation for more details

The best way to grant access to the bucket is to grant one or more IAM Roles access to the bucket via privileged_principal_arns. This IAM Role can be assumed by EC2 instances via their Instance Profile, or Kubernetes (EKS) services using IRSA. Entities outside of AWS can assume the Role via OIDC. (See this example of connecting GitHub to enable GitHub actions to assume AWS IAM roles, or use this Cloud Posse component if you are already using the Cloud Posse reference architecture.)

If neither of those approaches work, then as a last resort you can set user_enabled = true and this module will provision a basic IAM user with permissions to access the bucket. We do not recommend creating IAM users this way for any other purpose.

If an IAM user is created, the IAM user name is constructed using terraform-null-label and some input is required. The simplest input is name. By default the name will be converted to lower case and all non-alphanumeric characters except for hyphen will be removed. See the documentation for terraform-null-label to learn how to override these defaults if desired.

If an AWS Access Key is created, it is stored either in SSM Parameter Store or is provided as a module output, but not both. Using SSM Parameter Store is recommended because that will keep the secret from being easily accessible via Terraform remote state lookup, but the key will still be stored unencrypted in the Terraform state in any case.

Usage

Using BucketOwnerEnforced

module "s3_bucket" {
source = "cloudposse/s3-bucket/aws"
# Cloud Posse recommends pinning every module to a specific version
# version = "x.x.x"
name = "app"
stage = "test"
namespace = "eg"

s3_object_ownership = "BucketOwnerEnforced"
enabled = true
user_enabled = false
versioning_enabled = false

privileged_principal_actions = ["s3:GetObject", "s3:ListBucket", "s3:GetBucketLocation"]
privileged_principal_arns = [
{
(local.deployment_iam_role_arn) = [""]
},
{
(local.additional_deployment_iam_role_arn) = ["prefix1/", "prefix2/"]
}
]
}

Configuring S3 storage lifecycle:

locals {
lifecycle_configuration_rules = [{
enabled = true # bool
id = "v2rule"

abort_incomplete_multipart_upload_days = 1 # number

filter_and = null
expiration = {
days = 120 # integer > 0
}
noncurrent_version_expiration = {
newer_noncurrent_versions = 3 # integer > 0
noncurrent_days = 60 # integer >= 0
}
transition = [{
days = 30 # integer >= 0
storage_class = "STANDARD_IA" # string/enum, one of GLACIER, STANDARD_IA, ONEZONE_IA, INTELLIGENT_TIERING, DEEP_ARCHIVE, GLACIER_IR.
},
{
days = 60 # integer >= 0
storage_class = "ONEZONE_IA" # string/enum, one of GLACIER, STANDARD_IA, ONEZONE_IA, INTELLIGENT_TIERING, DEEP_ARCHIVE, GLACIER_IR.
}]
noncurrent_version_transition = [{
newer_noncurrent_versions = 3 # integer >= 0
noncurrent_days = 30 # integer >= 0
storage_class = "ONEZONE_IA" # string/enum, one of GLACIER, STANDARD_IA, ONEZONE_IA, INTELLIGENT_TIERING, DEEP_ARCHIVE, GLACIER_IR.
}]
}]
}

Allowing specific principal ARNs to perform actions on the bucket:

module "s3_bucket" {
source = "cloudposse/s3-bucket/aws"
# Cloud Posse recommends pinning every module to a specific version
# version = "x.x.x"
s3_object_ownership = "BucketOwnerEnforced"
enabled = true
user_enabled = true
versioning_enabled = false
allowed_bucket_actions = ["s3:GetObject", "s3:ListBucket", "s3:GetBucketLocation"]
name = "app"
stage = "test"
namespace = "eg"

privileged_principal_arns = [
{
"arn:aws:iam::123456789012:role/principal1" = ["prefix1/", "prefix2/"]
}, {
"arn:aws:iam::123456789012:role/principal2" = [""]
}]
privileged_principal_actions = [
"s3:PutObject",
"s3:PutObjectAcl",
"s3:GetObject",
"s3:DeleteObject",
"s3:ListBucket",
"s3:ListBucketMultipartUploads",
"s3:GetBucketLocation",
"s3:AbortMultipartUpload"
]
}

Variables

Required Variables

Optional Variables

access_key_enabled (bool) optional

Set to true to create an IAM Access Key for the created IAM user


Default value: true

acl (string) optional

The canned ACL to apply.
Deprecated by AWS in favor of bucket policies.
Automatically disabled if s3_object_ownership is set to "BucketOwnerEnforced".
Defaults to "private" for backwards compatibility, but we recommend setting s3_object_ownership to "BucketOwnerEnforced" instead.



Default value: "private"

allow_encrypted_uploads_only (bool) optional

Set to true to prevent uploads of unencrypted objects to S3 bucket


Default value: false

allow_ssl_requests_only (bool) optional

Set to true to require requests to use Secure Socket Layer (HTTPS/SSL). This will explicitly deny access to HTTP requests


Default value: false

allowed_bucket_actions (list(string)) optional

List of actions the user is permitted to perform on the S3 bucket


Default value:

[
"s3:PutObject",
"s3:PutObjectAcl",
"s3:GetObject",
"s3:DeleteObject",
"s3:ListBucket",
"s3:ListBucketMultipartUploads",
"s3:GetBucketLocation",
"s3:AbortMultipartUpload"
]
availability_zone_id (string) optional

The ID of the availability zone.


Default value: ""

block_public_acls (bool) optional

Set to false to disable the blocking of new public access lists on the bucket


Default value: true

block_public_policy (bool) optional

Set to false to disable the blocking of new public policies on the bucket


Default value: true

bucket_key_enabled (bool) optional

Set this to true to use Amazon S3 Bucket Keys for SSE-KMS, which may or may not reduce the number of AWS KMS requests.
For more information, see: https://docs.aws.amazon.com/AmazonS3/latest/userguide/bucket-key.html



Default value: false

bucket_name (string) optional

Bucket name. If provided, the bucket will be created with this name instead of generating the name from the context


Default value: null

cors_configuration optional

Specifies the allowed headers, methods, origins and exposed headers when using CORS on this bucket


Type:

list(object({
id = optional(string)
allowed_headers = optional(list(string))
allowed_methods = optional(list(string))
allowed_origins = optional(list(string))
expose_headers = optional(list(string))
max_age_seconds = optional(number)
}))

Default value: [ ]

create_s3_directory_bucket (bool) optional

Control the creation of the S3 directory bucket. Set to true to create the bucket, false to skip.


Default value: false

event_notification_details optional

S3 event notification details


Type:

object({
enabled = bool
eventbridge = optional(bool, false)
lambda_list = optional(list(object({
lambda_function_arn = string
events = optional(list(string), ["s3:ObjectCreated:*"])
filter_prefix = string
filter_suffix = string
})), [])

queue_list = optional(list(object({
queue_arn = string
events = optional(list(string), ["s3:ObjectCreated:*"])
})), [])

topic_list = optional(list(object({
topic_arn = string
events = optional(list(string), ["s3:ObjectCreated:*"])
})), [])
})

Default value:

{
"enabled": false
}
expected_bucket_owner (string) optional

Account ID of the expected bucket owner.
More information: https://docs.aws.amazon.com/AmazonS3/latest/userguide/bucket-owner-condition.html



Default value: null

force_destroy (bool) optional

When true, permits a non-empty S3 bucket to be deleted by first deleting all objects in the bucket.
THESE OBJECTS ARE NOT RECOVERABLE even if they were versioned and stored in Glacier.



Default value: false

grants optional

A list of policy grants for the bucket, taking a list of permissions.
Conflicts with acl. Set acl to null to use this.
Deprecated by AWS in favor of bucket policies.
Automatically disabled if s3_object_ownership is set to "BucketOwnerEnforced".



Type:

list(object({
id = string
type = string
permissions = list(string)
uri = string
}))

Default value: [ ]

ignore_public_acls (bool) optional

Set to false to disable the ignoring of public access lists on the bucket


Default value: true

kms_master_key_arn (string) optional

The AWS KMS master key ARN used for the SSE-KMS encryption. This can only be used when you set the value of sse_algorithm as aws:kms. The default aws/s3 AWS KMS master key is used if this element is absent while the sse_algorithm is aws:kms


Default value: ""

lifecycle_configuration_rules optional

A list of lifecycle V2 rules


Type:

list(object({
enabled = optional(bool, true)
id = string

abort_incomplete_multipart_upload_days = optional(number)

# `filter_and` is the `and` configuration block inside the `filter` configuration.
# This is the only place you should specify a prefix.
filter_and = optional(object({
object_size_greater_than = optional(number) # integer >= 0
object_size_less_than = optional(number) # integer >= 1
prefix = optional(string)
tags = optional(map(string), {})
}))
expiration = optional(object({
date = optional(string) # string, RFC3339 time format, GMT
days = optional(number) # integer > 0
expired_object_delete_marker = optional(bool)
}))
noncurrent_version_expiration = optional(object({
newer_noncurrent_versions = optional(number) # integer > 0
noncurrent_days = optional(number) # integer >= 0
}))
transition = optional(list(object({
date = optional(string) # string, RFC3339 time format, GMT
days = optional(number) # integer > 0
storage_class = optional(string)
# string/enum, one of GLACIER, STANDARD_IA, ONEZONE_IA, INTELLIGENT_TIERING, DEEP_ARCHIVE, GLACIER_IR.
})), [])

noncurrent_version_transition = optional(list(object({
newer_noncurrent_versions = optional(number) # integer >= 0
noncurrent_days = optional(number) # integer >= 0
storage_class = optional(string)
# string/enum, one of GLACIER, STANDARD_IA, ONEZONE_IA, INTELLIGENT_TIERING, DEEP_ARCHIVE, GLACIER_IR.
})), [])
}))

Default value: [ ]

lifecycle_rule_ids (list(string)) optional

DEPRECATED (use lifecycle_configuration_rules): A list of IDs to assign to corresponding lifecycle_rules


Default value: [ ]

lifecycle_rules optional

DEPRECATED (use lifecycle_configuration_rules): A list of lifecycle rules


Type:

list(object({
prefix = string
enabled = bool
tags = map(string)

enable_glacier_transition = bool
enable_deeparchive_transition = bool
enable_standard_ia_transition = bool
enable_current_object_expiration = bool
enable_noncurrent_version_expiration = bool

abort_incomplete_multipart_upload_days = number
noncurrent_version_glacier_transition_days = number
noncurrent_version_deeparchive_transition_days = number
noncurrent_version_expiration_days = number

standard_transition_days = number
glacier_transition_days = number
deeparchive_transition_days = number
expiration_days = number
}))

Default value: null

logging optional

Bucket access logging configuration. Empty list for no logging, list of 1 to enable logging.


Type:

list(object({
bucket_name = string
prefix = string
}))

Default value: [ ]

minimum_tls_version (string) optional

Set the minimum TLS version for in-transit traffic


Default value: null

object_lock_configuration optional

A configuration for S3 object locking. With S3 Object Lock, you can store objects using a write once, read many (WORM) model. Object Lock can help prevent objects from being deleted or overwritten for a fixed amount of time or indefinitely.


Type:

object({
mode = string # Valid values are GOVERNANCE and COMPLIANCE.
days = number
years = number
})

Default value: null

privileged_principal_actions (list(string)) optional

List of actions to permit privileged_principal_arns to perform on bucket and bucket prefixes (see privileged_principal_arns)


Default value: [ ]

privileged_principal_arns (list(map(list(string)))) optional

List of maps. Each map has a key, an IAM Principal ARN, whose associated value is
a list of S3 path prefixes to grant privileged_principal_actions permissions for that principal,
in addition to the bucket itself, which is automatically included. Prefixes should not begin with '/'.



Default value: [ ]

replication_rules (list(any)) optional

DEPRECATED (use s3_replication_rules): Specifies the replication rules for S3 bucket replication if enabled. You must also set s3_replication_enabled to true.


Default value: null

restrict_public_buckets (bool) optional

Set to false to disable the restricting of making the bucket public


Default value: true

s3_object_ownership (string) optional

Specifies the S3 object ownership control.
Valid values are ObjectWriter, BucketOwnerPreferred, and 'BucketOwnerEnforced'.
Defaults to "ObjectWriter" for backwards compatibility, but we recommend setting "BucketOwnerEnforced" instead.



Default value: "ObjectWriter"

s3_replica_bucket_arn (string) optional

A single S3 bucket ARN to use for all replication rules.
Note: The destination bucket can be specified in the replication rule itself
(which allows for multiple destinations), in which case it will take precedence over this variable.



Default value: ""

s3_replication_enabled (bool) optional

Set this to true and specify s3_replication_rules to enable replication. versioning_enabled must also be true.


Default value: false

s3_replication_permissions_boundary_arn (string) optional

Permissions boundary ARN for the created IAM replication role.


Default value: null

s3_replication_rules optional

Specifies the replication rules for S3 bucket replication if enabled. You must also set s3_replication_enabled to true.


Type:

list(object({
id = optional(string)
priority = optional(number)
prefix = optional(string)
status = optional(string, "Enabled")
# delete_marker_replication { status } had been flattened for convenience
delete_marker_replication_status = optional(string, "Disabled")
# Add the configuration as it appears in the resource, for consistency
# this nested version takes precedence if both are provided.
delete_marker_replication = optional(object({
status = string
}))

# destination_bucket is specified here rather than inside the destination object because before optional
# attributes, it made it easier to work with the Terraform type system and create a list of consistent type.
# It is preserved for backward compatibility, but the nested version takes priority if both are provided.
destination_bucket = optional(string) # destination bucket ARN, overrides s3_replica_bucket_arn

destination = object({
bucket = optional(string) # destination bucket ARN, overrides s3_replica_bucket_arn
storage_class = optional(string, "STANDARD")
# replica_kms_key_id at this level is for backward compatibility, and is overridden by the one in `encryption_configuration`
replica_kms_key_id = optional(string, "")
encryption_configuration = optional(object({
replica_kms_key_id = string
}))
access_control_translation = optional(object({
owner = string
}))
# account_id is for backward compatibility, overridden by account
account_id = optional(string)
account = optional(string)
# For convenience, specifying either metrics or replication_time enables both
metrics = optional(object({
event_threshold = optional(object({
minutes = optional(number, 15) # Currently 15 is the only valid number
}), { minutes = 15 })
status = optional(string, "Enabled")
}), { status = "Disabled" })
# To preserve backward compatibility, Replication Time Control (RTC) is automatically enabled
# when metrics are enabled. To enable metrics without RTC, you must explicitly configure
# replication_time.status = "Disabled".
replication_time = optional(object({
time = optional(object({
minutes = optional(number, 15) # Currently 15 is the only valid number
}), { minutes = 15 })
status = optional(string)
}))
})

source_selection_criteria = optional(object({
replica_modifications = optional(object({
status = string # Either Enabled or Disabled
}))
sse_kms_encrypted_objects = optional(object({
status = optional(string)
}))
}))
# filter.prefix overrides top level prefix
filter = optional(object({
prefix = optional(string)
tags = optional(map(string), {})
}))
}))

Default value: null

s3_replication_source_roles (list(string)) optional

Cross-account IAM Role ARNs that will be allowed to perform S3 replication to this bucket (for replication within the same AWS account, it's not necessary to adjust the bucket policy).


Default value: [ ]

s3_request_payment_configuration optional

S3 request payment configuration


Type:

object({
enabled = bool
expected_bucket_owner = optional(string)
payer = string
})

Default value:

{
"enabled": false,
"payer": "BucketOwner"
}
source_ip_allow_list (list(string)) optional

List of IP addresses to allow to perform all actions to the bucket


Default value: [ ]

source_policy_documents (list(string)) optional

List of IAM policy documents (in JSON) that are merged together into the exported document.
Statements defined in source_policy_documents must have unique SIDs.
Statement having SIDs that match policy SIDs generated by this module will override them.



Default value: [ ]

sse_algorithm (string) optional

The server-side encryption algorithm to use. Valid values are AES256 and aws:kms


Default value: "AES256"

ssm_base_path (string) optional

The base path for SSM parameters where created IAM user's access key is stored


Default value: "/s3_user/"

store_access_key_in_ssm (bool) optional

Set to true to store the created IAM user's access key in SSM Parameter Store,
false to store them in Terraform state as outputs.
Since Terraform state would contain the secrets in plaintext,
use of SSM Parameter Store is recommended.



Default value: false

transfer_acceleration_enabled (bool) optional

Set this to true to enable S3 Transfer Acceleration for the bucket.
Note: When this is set to false Terraform does not perform drift detection
and will not disable Transfer Acceleration if it was enabled outside of Terraform.
To disable it via Terraform, you must set this to true and then to false.
Note: not all regions support Transfer Acceleration.



Default value: false

user_enabled (bool) optional

Set to true to create an IAM user with permission to access the bucket


Default value: false

user_permissions_boundary_arn (string) optional

Permission boundary ARN for the IAM user created to access the bucket.


Default value: null

versioning_enabled (bool) optional

A state of versioning. Versioning is a means of keeping multiple variants of an object in the same bucket


Default value: true

website_configuration optional

Specifies the static website hosting configuration object


Type:

list(object({
index_document = string
error_document = string
routing_rules = list(object({
condition = object({
http_error_code_returned_equals = string
key_prefix_equals = string
})
redirect = object({
host_name = string
http_redirect_code = string
protocol = string
replace_key_prefix_with = string
replace_key_with = string
})
}))
}))

Default value: [ ]

website_redirect_all_requests_to optional

If provided, all website requests will be redirected to the specified host name and protocol


Type:

list(object({
host_name = string
protocol = string
}))

Default value: [ ]

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

access_key_id

The access key ID, if var.user_enabled && var.access_key_enabled.
While sensitive, it does not need to be kept secret, so this is output regardless of var.store_access_key_in_ssm.


access_key_id_ssm_path

The SSM Path under which the S3 User's access key ID is stored

bucket_arn

Bucket ARN

bucket_domain_name

FQDN of bucket

bucket_id

Bucket Name (aka ID)

bucket_region

Bucket region

bucket_regional_domain_name

The bucket region-specific domain name

bucket_website_domain

The bucket website domain, if website is enabled

bucket_website_endpoint

The bucket website endpoint, if website is enabled

enabled

Is module enabled

replication_role_arn

The ARN of the replication IAM Role

secret_access_key

The secret access key will be output if created and not stored in SSM. However, the secret access key, if created,
will be written to the Terraform state file unencrypted, regardless of any other settings.
See the Terraform documentation for more details.


secret_access_key_ssm_path

The SSM Path under which the S3 User's secret access key is stored

user_arn

The ARN assigned by AWS for the user

user_enabled

Is user creation enabled

user_name

Normalized IAM user name

user_unique_id

The user unique ID assigned by AWS

Dependencies

Requirements

  • terraform, version: >= 1.3.0
  • aws, version: >= 4.9.0
  • time, version: >= 0.7

Providers

  • aws, version: >= 4.9.0
  • time, version: >= 0.7

Modules

NameVersionSourceDescription
s3_user1.2.0cloudposse/iam-s3-user/awsn/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: