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Component: eks/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"

Requirements

Name Version
terraform >= 1.3.0
aws >= 4.9.0
helm >= 2.0
kubernetes >= 2.22.0

Providers

Name Version
aws >= 4.9.0
kubernetes >= 2.22.0

Modules

Name Source Version
efs cloudposse/stack-config/yaml//modules/remote-state 1.5.0
eks cloudposse/stack-config/yaml//modules/remote-state 1.5.0
iam_roles ../../account-map/modules/iam-roles n/a
this cloudposse/label/null 0.25.0

Resources

Name Type
kubernetes_storage_class_v1.ebs resource
kubernetes_storage_class_v1.efs resource
aws_eks_cluster_auth.eks data source

Inputs

Name Description Type Default Required
additional_tag_map 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.		 map(string) {} no
attributes 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.		 list(string) [] no
context 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.		 any 
{
  "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
}
 no
delimiter Delimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.		 string null no
descriptor_formats 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).		 any {} no
ebs_storage_classes A map of storage class name to EBS parameters to create 
map(object({
    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
  }))
 {} no
efs_storage_classes A map of storage class name to EFS parameters to create 
map(object({
    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")
  }))
 {} no
eks_component_name The name of the EKS component for the cluster in which to create the storage classes string "eks/cluster" no
enabled Set to false to prevent the module from creating any resources bool null no
environment ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT' string null no
helm_manifest_experiment_enabled Enable storing of the rendered manifest for helm_release so the full diff of what is changing can been seen in the plan bool false no
id_length_limit 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.		 number null no
kube_data_auth_enabled 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.		 bool false no
kube_exec_auth_aws_profile The AWS config profile for aws eks get-token to use string "" no
kube_exec_auth_aws_profile_enabled If true, pass kube_exec_auth_aws_profile as the profile to aws eks get-token bool false no
kube_exec_auth_enabled 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.		 bool true no
kube_exec_auth_role_arn The role ARN for aws eks get-token to use string "" no
kube_exec_auth_role_arn_enabled If true, pass kube_exec_auth_role_arn as the role ARN to aws eks get-token bool true no
kubeconfig_context Context to choose from the Kubernetes kube config file string "" no
kubeconfig_exec_auth_api_version The Kubernetes API version of the credentials returned by the exec auth plugin string "client.authentication.k8s.io/v1beta1" no
kubeconfig_file The Kubernetes provider config_path setting to use when kubeconfig_file_enabled is true string "" no
kubeconfig_file_enabled If true, configure the Kubernetes provider with kubeconfig_file and use that kubeconfig file for authenticating to the EKS cluster bool false no
label_key_case 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.		 string null no
label_order 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.		 list(string) null no
label_value_case 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.		 string null no
labels_as_tags 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.		 set(string) 
[
  "default"
]
 no
name 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.		 string null no
namespace ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique string null no
regex_replace_chars 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.		 string null no
region AWS Region. string n/a yes
stage ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release' string null no
tags Additional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.		 map(string) {} no
tenant ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for string null no

Outputs

Name Description
storage_classes Storage classes created by this module

Related How-to Guides

References