Module: iam-s3-user
Terraform module to provision a basic IAM user with permissions to access S3 resources, e.g. to give the user read/write/delete access to the objects in an S3 bucket.
Suitable for CI/CD systems (e.g. TravisCI, CircleCI) or systems which are external to AWS that cannot leverage AWS IAM Instance Profiles or AWS OIDC.
By default, IAM users, groups, and roles have no access to AWS resources. IAM policies are the means by which privileges are granted to users, groups, or roles. It is recommended that IAM policies be applied directly to groups and roles but not users. This module intentionally attaches an IAM policy directly to the user and does not use groups
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 module outputs are stored in plaintext in the Terraform state file.
Usage
This example will create an IAM user and allow read access to all objects in the S3 bucket examplebucket
module "s3_user" {
source = "cloudposse/iam-s3-user/aws"
# Cloud Posse recommends pinning every module to a specific version
# version = "x.x.x"
namespace = "eg"
stage = "test"
name = "app"
s3_actions = ["s3:GetObject"]
s3_resources = "arn:aws:s3:::examplebucket/*"
}
Variables
Required Variables
s3_resources(list(string)) requiredS3 resources to apply the actions specified in the policy
Optional Variables
create_iam_access_key(bool) optionalSet
trueto create an IAM Access Key for the user.
To rotate the key, setfalseto delete it and then back totrueto create a new key.
Best practice is to never create a key and instead authenticate with OIDC or some other mechanism
that does not require long-lived bearer tokens.Default value:
trueforce_destroy(bool) optionalDestroy even if it has non-Terraform-managed IAM access keys, login profiles or MFA devices
Default value:
falsepath(string) optionalPath in which to create the user
Default value:
"/"permissions_boundary(string) optionalPermissions Boundary ARN to attach to our created user
Default value:
nulls3_actions(list(string)) optionalActions to allow in the policy
Default value:
[
"s3:GetObject"
]ssm_base_path(string) optionalThe base path for SSM parameters where secrets are stored
Default value:
"/s3_user/"ssm_enabled(bool) optionalSet
trueto store secrets in SSM Parameter Store,
falseto store secrets in Terraform state as outputs.
Since Terraform state would contain the secrets in plaintext,
use of SSM Parameter Store is recommended.Default value:
false
Context Variables
The following variables are defined in the context.tf file of this module and part of the terraform-null-label pattern.
context.tf file of this module and part of the terraform-null-label pattern.additional_tag_map(map(string)) optionalAdditional key-value pairs to add to each map in
tags_as_list_of_maps. Not added totagsorid.
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)) optionalID element. Additional attributes (e.g.
workersorcluster) to add toid,
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 thedelimiter
and treated as a single ID element.Required: No
Default value:
[ ]context(any) optionalSingle object for setting entire context at once.
See description of individual variables for details.
Leave string and numeric variables asnullto 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) optionalDelimiter to be used between ID elements.
Defaults to-(hyphen). Set to""to use no delimiter at all.Required: No
Default value:
nulldescriptor_formats(any) optionalDescribe additional descriptors to be output in the
descriptorsoutput map.
Map of maps. Keys are names of descriptors. Values are maps of the form
\{<br/> format = string<br/> labels = list(string)<br/> \}
(Type isanyso the map values can later be enhanced to provide additional options.)
formatis a Terraform format string to be passed to theformat()function.
labelsis a list of labels, in order, to pass toformat()function.
Label values will be normalized before being passed toformat()so they will be
identical to how they appear inid.
Default is{}(descriptorsoutput will be empty).Required: No
Default value:
{ }enabled(bool) optionalSet to false to prevent the module from creating any resources
Required: NoDefault value:
nullenvironment(string) optionalID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'
Required: NoDefault value:
nullid_length_limit(number) optionalLimit
idto this many characters (minimum 6).
Set to0for unlimited length.
Set tonullfor keep the existing setting, which defaults to0.
Does not affectid_full.Required: No
Default value:
nulllabel_key_case(string) optionalControls the letter case of the
tagskeys (label names) for tags generated by this module.
Does not affect keys of tags passed in via thetagsinput.
Possible values:lower,title,upper.
Default value:title.Required: No
Default value:
nulllabel_order(list(string)) optionalThe 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:
nulllabel_value_case(string) optionalControls 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 thetagsinput.
Possible values:lower,title,upperandnone(no transformation).
Set this totitleand setdelimiterto""to yield Pascal Case IDs.
Default value:lower.Required: No
Default value:
nulllabels_as_tags(set(string)) optionalSet of labels (ID elements) to include as tags in the
tagsoutput.
Default is to include all labels.
Tags with empty values will not be included in thetagsoutput.
Set to[]to suppress all generated tags.
Notes:
The value of thenametag, if included, will be theid, not thename.
Unlike othernull-labelinputs, the initial setting oflabels_as_tagscannot be
changed in later chained modules. Attempts to change it will be silently ignored.Required: No
Default value:
[
"default"
]name(string) optionalID element. Usually the component or solution name, e.g. 'app' or 'jenkins'.
This is the only ID element not also included as atag.
The "name" tag is set to the fullidstring. There is no tag with the value of thenameinput.Required: No
Default value:
nullnamespace(string) optionalID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique
Required: NoDefault value:
nullregex_replace_chars(string) optionalTerraform 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:
nullstage(string) optionalID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'
Required: NoDefault value:
nulltags(map(string)) optionalAdditional 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) optionalID element (Rarely used, not included by default). A customer identifier, indicating who this instance of a resource is for
Required: NoDefault value:
null
Outputs
access_key_idAccess Key ID
access_key_id_ssm_pathThe SSM Path under which the S3 User's access key ID is stored
secret_access_keySecret Access Key. This will be written to the state file in plain-text
secret_access_key_ssm_pathThe SSM Path under which the S3 User's secret access key is stored
user_arnThe ARN assigned by AWS for the user
user_nameNormalized IAM user name
user_unique_idThe user unique ID assigned by AWS
Dependencies
Requirements
terraform, version:>= 0.13.0aws, version:>= 2.0
Providers
aws, version:>= 2.0
Modules
| Name | Version | Source | Description |
|---|---|---|---|
s3_user | 1.2.1 | cloudposse/iam-system-user/aws | n/a |
this | 0.25.0 | cloudposse/label/null | n/a |
Resources
The following resources are used by this module:
aws_iam_user_policy.default(resource)
Data Sources
The following data sources are used by this module:
aws_iam_policy_document.default(data source)