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storage-class

This component is responsible for provisioning StorageClasses in an EKS cluster. See the list of guides and references linked at the bottom of this README for more information.

A StorageClass provides part of the configuration for a PersistentVolumeClaim, which copies the configuration when it is created. Thus, you can delete a StorageClass without affecting existing PersistentVolumeClaims, and changes to a StorageClass do not propagate to existing PersistentVolumeClaims.

Usage​

Stack Level: Regional, per cluster

This component can create storage classes backed by EBS or EFS, and is intended to be used with the corresponding EKS add-ons aws-ebs-csi-driver and aws-efs-csi-driver respectively. In the case of EFS, this component also requires that you have provisioned an EFS filesystem in the same region as your cluster, and expects you have used the efs (previously eks/efs) component to do so. The EFS storage classes will get the file system ID from the EFS component's output.

Note: Default Storage Class​

Exactly one StorageClass can be designated as the default StorageClass for a cluster. This default StorageClass is then used by PersistentVolumeClaims that do not specify a storage class.

Prior to Kubernetes 1.26, if more than one StorageClass is marked as default, a PersistentVolumeClaim without storageClassName explicitly specified cannot be created. In Kubernetes 1.26 and later, if more than one StorageClass is marked as default, the last one created will be used, which means you can get by with just ignoring the default "gp2" StorageClass that EKS creates for you.

EKS always creates a default storage class for the cluster, typically an EBS backed class named gp2. Find out what the default storage class is for your cluster by running this command:

# You only need to run `set-cluster` when you are changing target clusters
set-cluster <cluster-name> admin # replace admin with other role name if desired
kubectl get storageclass

This will list the available storage classes, with the default one marked with (default) next to its name.

If you want to change the default, you can unset the existing default manually, like this:

SC_NAME=gp2 # Replace with the name of the storage class you want to unset as default
# You only need to run `set-cluster` when you are changing target clusters
set-cluster <cluster-name> admin # replace admin with other role name if desired
kubectl patch storageclass $SC_NAME -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'

Or you can import the existing default storage class into Terraform and manage or delete it entirely, like this:

SC_NAME=gp2 # Replace with the name of the storage class you want to unset as default
atmos terraform import eks/storage-class 'kubernetes_storage_class_v1.ebs["'${SC_NAME}'"]' $SC_NAME -s=core-usw2-dev

View the parameters of a storage class by running this command:

SC_NAME=gp2 # Replace with the name of the storage class you want to view
# You only need to run `set-cluster` when you are changing target clusters
set-cluster <cluster-name> admin # replace admin with other role name if desired
kubectl get storageclass $SC_NAME -o yaml

You can then match that configuration, except that you cannot omit allow_volume_exansion.

ebs_storage_classes:
  gp2:
    make_default_storage_class: true
    include_tags: false
    # Preserve values originally set by eks/cluster.
    # Set to "" to omit.
    provisioner: kubernetes.io/aws-ebs
    parameters:
      type: gp2
      encrypted: ""

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

eks/storage-class:
  vars:
    ebs_storage_classes:
      gp2:
        make_default_storage_class: false
        include_tags: false
        # Preserve values originally set by eks/cluster.
        # Set to "" to omit.
        provisioner: kubernetes.io/aws-ebs
        parameters:
          type: gp2
          encrypted: ""
      gp3:
        make_default_storage_class: true
        parameters:
          type: gp3
    efs_storage_classes:
      efs-sc:
        make_default_storage_class: false
        efs_component_name: "efs" # Replace with the name of the EFS component, previously "eks/efs"

Variables​

Required Variables​

region (string) required

AWS Region.

Optional Variables​

ebs_storage_classes optional

A map of storage class name to EBS parameters to create


Type:

map(object({
enabled                    = optional(bool, true)
make_default_storage_class = optional(bool, false)
include_tags               = optional(bool, true) # If true, StorageClass will set our tags on created EBS volumes
labels                     = optional(map(string), null)
reclaim_policy             = optional(string, "Delete")
volume_binding_mode        = optional(string, "WaitForFirstConsumer")
mount_options              = optional(list(string), null)
# Allowed topologies are poorly documented, and poorly implemented.
# According to the API spec https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.26/#storageclass-v1-storage-k8s-io
# it should be a list of objects with a `matchLabelExpressions` key, which is a list of objects with `key` and `values` keys.
# However, the Terraform resource only allows a single object in a matchLabelExpressions block, not a list,
# the EBS driver appears to only allow a single matchLabelExpressions block, and it is entirely unclear
# what should happen if either of the lists has more than one element.
# So we simplify it here to be singletons, not lists, and allow for a future change to the resource to support lists,
# and a future replacement for this flattened object which can maintain backward compatibility.
allowed_topologies_match_label_expressions = optional(object({
  key    = optional(string, "topology.ebs.csi.aws.com/zone")
  values = list(string)
}), null)
allow_volume_expansion = optional(bool, true)
# parameters, see https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/docs/parameters.md
parameters = object({
  fstype                     = optional(string, "ext4") # "csi.storage.k8s.io/fstype"
  type                       = optional(string, "gp3")
  iopsPerGB                  = optional(string, null)
  allowAutoIOPSPerGBIncrease = optional(string, null) # "true" or "false"
  iops                       = optional(string, null)
  throughput                 = optional(string, null)

  encrypted    = optional(string, "true")
  kmsKeyId     = optional(string, null) # ARN of the KMS key to use for encryption. If not specified, the default key is used.
  blockExpress = optional(string, null) # "true" or "false"
  blockSize    = optional(string, null)
})
provisioner = optional(string, "ebs.csi.aws.com")

# TODO: support tags
# https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/docs/tagging.md
}))

Default value: { }

efs_storage_classes optional

A map of storage class name to EFS parameters to create


Type:

map(object({
enabled                    = optional(bool, true)
make_default_storage_class = optional(bool, false)
labels                     = optional(map(string), null)
efs_component_name         = optional(string, "eks/efs")
reclaim_policy             = optional(string, "Delete")
volume_binding_mode        = optional(string, "Immediate")
# Mount options are poorly documented.
# TLS is now the default and need not be specified. https://github.com/kubernetes-sigs/aws-efs-csi-driver/tree/master/docs#encryption-in-transit
# Other options include `lookupcache` and `iam`.
mount_options = optional(list(string), null)
parameters = optional(object({
  basePath         = optional(string, "/efs_controller")
  directoryPerms   = optional(string, "700")
  provisioningMode = optional(string, "efs-ap")
  gidRangeStart    = optional(string, null)
  gidRangeEnd      = optional(string, null)
  # Support for cross-account EFS mounts
  # See https://github.com/kubernetes-sigs/aws-efs-csi-driver/tree/master/examples/kubernetes/cross_account_mount
  # and for gritty details on secrets: https://kubernetes-csi.github.io/docs/secrets-and-credentials-storage-class.html
  az                           = optional(string, null)
  provisioner-secret-name      = optional(string, null) # "csi.storage.k8s.io/provisioner-secret-name"
  provisioner-secret-namespace = optional(string, null) # "csi.storage.k8s.io/provisioner-secret-namespace"
}), {})
provisioner = optional(string, "efs.csi.aws.com")
}))

Default value: { }

eks_component_name (string) optional

The name of the EKS component for the cluster in which to create the storage classes


Default value: "eks/cluster"

helm_manifest_experiment_enabled (bool) optional

Enable storing of the rendered manifest for helm_release so the full diff of what is changing can been seen in the plan


Default value: false

kube_data_auth_enabled (bool) optional

If true, use an aws_eks_cluster_auth data source to authenticate to the EKS cluster.
Disabled by kubeconfig_file_enabled or kube_exec_auth_enabled.



Default value: false

kube_exec_auth_aws_profile (string) optional

The AWS config profile for aws eks get-token to use


Default value: ""

kube_exec_auth_aws_profile_enabled (bool) optional

If true, pass kube_exec_auth_aws_profile as the profile to aws eks get-token


Default value: false

kube_exec_auth_enabled (bool) optional

If true, use the Kubernetes provider exec feature to execute aws eks get-token to authenticate to the EKS cluster.
Disabled by kubeconfig_file_enabled, overrides kube_data_auth_enabled.



Default value: true

kube_exec_auth_role_arn (string) optional

The role ARN for aws eks get-token to use


Default value: ""

kube_exec_auth_role_arn_enabled (bool) optional

If true, pass kube_exec_auth_role_arn as the role ARN to aws eks get-token


Default value: true

kubeconfig_context (string) optional

Context to choose from the Kubernetes config file.
If supplied, kubeconfig_context_format will be ignored.



Default value: ""

kubeconfig_context_format (string) optional

A format string to use for creating the kubectl context name when
kubeconfig_file_enabled is true and kubeconfig_context is not supplied.
Must include a single %s which will be replaced with the cluster name.



Default value: ""

kubeconfig_exec_auth_api_version (string) optional

The Kubernetes API version of the credentials returned by the exec auth plugin


Default value: "client.authentication.k8s.io/v1beta1"

kubeconfig_file (string) optional

The Kubernetes provider config_path setting to use when kubeconfig_file_enabled is true


Default value: ""

kubeconfig_file_enabled (bool) optional

If true, configure the Kubernetes provider with kubeconfig_file and use that kubeconfig file for authenticating to the EKS cluster


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.

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​

storage_classes

Storage classes created by this module

Dependencies​

Requirements​

  • terraform, version: >= 1.3.0
  • aws, version: >= 4.9.0
  • helm, version: >= 2.0
  • kubernetes, version: >= 2.22.0

Providers​

  • aws, version: >= 4.9.0
  • kubernetes, version: >= 2.22.0

Modules​

NameVersionSourceDescription
efs1.5.0cloudposse/stack-config/yaml//modules/remote-staten/a
eks1.5.0cloudposse/stack-config/yaml//modules/remote-staten/a
iam_roleslatest../../account-map/modules/iam-rolesn/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:

References​