Deploy KMS Encrypted Bucket

Application Scenario

Object Storage Service (OBS) is a highly available, highly reliable, high-performance, secure, and low-cost object storage service provided by Huawei Cloud. OBS provides massive, secure, highly reliable, and low-cost data storage capabilities, supporting multiple storage types, including standard storage, infrequent access storage, archive storage, etc., meeting storage requirements for different business scenarios.

OBS KMS encrypted buckets are an important security feature of the OBS service, used to provide server-side encryption protection for storage buckets. Through KMS (Key Management Service) encryption, enterprises can ensure that data stored in OBS is encrypted and protected, meeting data security and compliance requirements. KMS encryption supports multiple encryption algorithms, provides key management and rotation functions, providing enterprise-level data security protection for enterprises. This best practice will introduce how to use Terraform to automatically deploy OBS KMS encrypted buckets, including KMS key creation and OBS bucket configuration.

Related Resources/Data Sources

This best practice involves the following main resources and data sources:

Resources

• KMS Key Resource (huaweicloud_kms_key)

• OBS Bucket Resource (huaweicloud_obs_bucket)

Resource/Data Source Dependencies

huaweicloud_kms_key.test
    └── huaweicloud_obs_bucket.test

Operation Steps

1. Script Preparation

Prepare the TF file (e.g., main.tf) in the specified workspace for writing the current best practice script, ensuring that it (or other TF files in the same directory) contains the provider version declaration and Huawei Cloud authentication information required for deploying resources. Refer to the "Preparation Before Deploying Huawei Cloud Resources" document for configuration introduction.

2. Create KMS Key

Add the following script to the TF file (e.g., main.tf) to instruct Terraform to create a KMS key resource:

variable "bucket_encryption" {
  description = "Whether OBS bucket encryption is enabled"
  type        = bool
  default     = true
}

variable "bucket_encryption_key_id" {
  description = "OBS bucket encryption key ID"
  type        = string
  default     = ""
  nullable    = false
}

variable "key_alias" {
  description = "KMS key alias"
  type        = string
  default     = ""
  nullable    = false

  validation {
    condition     = var.key_alias != "" && var.bucket_encryption && var.bucket_encryption_key_id == ""
    error_message = "key_alias must be set when bucket_encryption is true and bucket_encryption_key_id is not set."
  }
}

variable "key_usage" {
  description = "KMS key usage"
  type        = string
  default     = "ENCRYPT_DECRYPT"
}

# Create a KMS key resource under the specified region (if the region parameter is omitted, it defaults to the region specified in the current provider block)
resource "huaweicloud_kms_key" "test" {
  count = var.bucket_encryption && var.bucket_encryption_key_id == "" ? 1 : 0

  key_alias = var.key_alias
  key_usage = var.key_usage
}

Parameter Description:

• key_alias: Key alias, assigned by referencing the input variable key_alias

• key_usage: Key usage, assigned by referencing the input variable key_usage

• count: Conditional creation, creates when encryption is enabled and key ID is not specified

3. Create OBS Bucket

Add the following script to the TF file (e.g., main.tf) to instruct Terraform to create an OBS bucket resource:

variable "bucket_name" {
  description = "OBS bucket name"
  type        = string
}

variable "bucket_storage_class" {
  description = "OBS bucket storage class"
  type        = string
  default     = "STANDARD"
}

variable "bucket_acl" {
  description = "OBS bucket access control list"
  type        = string
  default     = "private"
}

variable "bucket_sse_algorithm" {
  description = "OBS bucket server-side encryption algorithm"
  type        = string
  default     = "kms"
}

variable "bucket_force_destroy" {
  description = "Whether OBS bucket force destroy is enabled"
  type        = bool
  default     = true
}

variable "bucket_tags" {
  description = "OBS bucket tags"
  type        = map(string)
  default     = {}
}

# Create an OBS bucket resource under the specified region (if the region parameter is omitted, it defaults to the region specified in the current provider block)
resource "huaweicloud_obs_bucket" "test" {
  bucket        = var.bucket_name
  storage_class = var.bucket_storage_class
  acl           = var.bucket_acl
  encryption    = var.bucket_encryption
  sse_algorithm = var.bucket_encryption ? var.bucket_sse_algorithm : null
  kms_key_id    = var.bucket_encryption ? var.bucket_encryption_key_id != "" ? var.bucket_encryption_key_id : huaweicloud_kms_key.test[0].id : null
  force_destroy = var.bucket_force_destroy
  tags          = var.bucket_tags

  lifecycle {
    ignore_changes = [
      sse_algorithm
    ]
  }
}

Parameter Description:

• bucket: Bucket name, assigned by referencing the input variable bucket_name

• storage_class: Storage class, assigned by referencing the input variable bucket_storage_class

• acl: Access control list, assigned by referencing the input variable bucket_acl

• encryption: Whether encryption is enabled, assigned by referencing the input variable bucket_encryption

• sse_algorithm: Server-side encryption algorithm, uses kms algorithm when encryption is enabled

• kms_key_id: KMS key ID, prioritizes using input variable, uses created KMS key if empty

• force_destroy: Force destroy, assigned by referencing the input variable bucket_force_destroy

• tags: Tags, assigned by referencing the input variable bucket_tags

4. Preset Input Parameters Required for Resource Deployment (Optional)

In this practice, some resources and data sources use input variables to assign values to configuration content. These input parameters need to be manually entered during subsequent deployments. At the same time, Terraform provides a method to preset these configurations through tfvars files, which can avoid repeated input during each execution.

Create a terraform.tfvars file in the working directory with the following example content:

# Authentication information
region_name = "cn-north-4"
access_key  = "your-access-key"
secret_key  = "your-secret-key"

# KMS key configuration
key_alias   = "tf-test-obs-key"
key_usage   = "ENCRYPT_DECRYPT"

# OBS bucket configuration
bucket_name        = "tf-test-obs-bucket"
bucket_storage_class = "STANDARD"
bucket_acl         = "private"
bucket_encryption  = true
bucket_sse_algorithm = "kms"
bucket_force_destroy = true
bucket_tags        = {
  environment = "test"
  created_by  = "terraform"
}

Usage:

1. Save the above content as terraform.tfvars file in the working directory (this file name allows users to automatically import the content of this tfvars file when executing terraform commands; for other names, .auto needs to be added before tfvars, such as variables.auto.tfvars)

2. Modify parameter values as needed

3. When executing terraform plan or terraform apply, Terraform will automatically read the variable values from this file

In addition to using terraform.tfvars file, variable values can also be set in the following ways:

1. Command line parameters: terraform apply -var="bucket_name=my-bucket" -var="key_alias=my-key"

2. Environment variables: export TF_VAR_bucket_name=my-bucket

3. Custom named variable files: terraform apply -var-file="custom.tfvars"

Note: If the same variable is set in multiple ways, Terraform will use the variable value according to the following priority: command line parameters > variable files > environment variables > default values.

5. Initialize and Apply Terraform Configuration

After completing the above script configuration, execute the following steps to create resources:

1. Run terraform init to initialize the environment

2. Run terraform plan to view the resource creation plan

3. After confirming the resource plan is correct, run terraform apply to start creating KMS encrypted buckets

4. Run terraform show to view the created KMS encrypted buckets

Reference Information

• Huawei Cloud OBS Product Documentation

• Huawei Cloud Provider Documentation

• Best Practice Source Code Reference For OBS KMS Encrypted Bucket