--- layout: "docs" page_title: "DynamoDB - Storage Backends - Configuration" sidebar_title: "DynamoDB" sidebar_current: "docs-configuration-storage-dynamodb" description: |- The DynamoDB storage backend is used to persist Vault's data in DynamoDB table. --- # DynamoDB Storage Backend The DynamoDB storage backend is used to persist Vault's data in [DynamoDB][dynamodb] table. - **High Availability** – the DynamoDB storage backend supports high availability. Because DynamoDB uses the time on the Vault node to implement the session lifetimes on its locks, significant clock skew across Vault nodes could cause contention issues on the lock. - **Community Supported** – the DynamoDB storage backend is supported by the community. While it has undergone review by HashiCorp employees, they may not be as knowledgeable about the technology. If you encounter problems with this storage backend, you could be referred to the original author for support. ```hcl storage "dynamodb" { ha_enabled = "true" region = "us-west-2" table = "vault-data" } ``` For more information about the read/write capacity of DynamoDB tables, please see the [official AWS DynamoDB documentation][dynamodb-rw-capacity]. ## DynamoDB Parameters - `endpoint` `(string: "")` – Specifies an alternative, AWS compatible, DynamoDB endpoint. This can also be provided via the environment variable `AWS_DYNAMODB_ENDPOINT`. - `ha_enabled` `(string: "false")` – Specifies whether this backend should be used to run Vault in high availability mode. Valid values are "true" or "false". This can also be provided via the environment variable `DYNAMODB_HA_ENABLED`. - `max_parallel` `(string: "128")` – Specifies the maximum number of concurrent requests. - `region` `(string "us-east-1")` – Specifies the AWS region. This can also be provided via the environment variable `AWS_DEFAULT_REGION`. - `read_capacity` `(int: 5)` – Specifies the maximum number of reads consumed per second on the table, for use if Vault creates the DynamoDB table. This has no effect if the `table` already exists. This can also be provided via the environment variable `AWS_DYNAMODB_READ_CAPACITY`. - `table` `(string: "vault-dynamodb-backend")` – Specifies the name of the DynamoDB table in which to store Vault data. If the specified table does not yet exist, it will be created during initialization. This can also be provided via the environment variable `AWS_DYNAMODB_TABLE`. See the information on the table schema below. - `write_capacity` `(int: 5)` – Specifies the maximum number of writes performed per second on the table, for use if Vault creates the DynamoDB table. This value has no effect if the `table` already exists. This can also be provided via the environment variable `AWS_DYNAMODB_WRITE_CAPACITY`. The following settings are used for authenticating to AWS. If you are running your Vault server on an EC2 instance, you can also make use of the EC2 instance profile service to provide the credentials Vault will use to make DynamoDB API calls. Leaving the `access_key` and `secret_key` fields empty will cause Vault to attempt to retrieve credentials from the AWS metadata service. - `access_key` `(string: )` – Specifies the AWS access key. This can also be provided via the environment variable `AWS_ACCESS_KEY_ID`. - `secret_key` `(string: )` – Specifies the AWS secret key. This can also be provided via the environment variable `AWS_SECRET_ACCESS_KEY`. - `session_token` `(string: "")` – Specifies the AWS session token. This can also be provided via the environment variable `AWS_SESSION_TOKEN`. ## Required AWS Permissions The governing policy for the IAM user or EC2 instance profile that Vault uses to access DynamoDB must contain the following permissions for Vault to perform the required operations on the DynamoDB table: ```javascript "Statement": [ { "Action": [ "dynamodb:DescribeLimits", "dynamodb:DescribeTimeToLive", "dynamodb:ListTagsOfResource", "dynamodb:DescribeReservedCapacityOfferings", "dynamodb:DescribeReservedCapacity", "dynamodb:ListTables", "dynamodb:BatchGetItem", "dynamodb:BatchWriteItem", "dynamodb:CreateTable", "dynamodb:DeleteItem", "dynamodb:GetItem", "dynamodb:GetRecords", "dynamodb:PutItem", "dynamodb:Query", "dynamodb:UpdateItem", "dynamodb:Scan", "dynamodb:DescribeTable" ], "Effect": "Allow", "Resource": [ "arn:aws:dynamodb:us-east-1:... dynamodb table ARN" ] }, ``` ## Table Schema If you are going to create the DynamoDB table prior to the execution and initialization of Vault, you will need to create a table with these attributes: * Primary partition key: "Path", a string * Primary sort key: "Key", a string You might create the table via Terraform, with a configuration similar to this: ``` resource "aws_dynamodb_table" "dynamodb-table" { name = "${var.dynamoTable}" read_capacity = 1 write_capacity = 1 hash_key = "Path" range_key = "Key" attribute [ { name = "Path" type = "S" }, { name = "Key" type = "S" } ] tags { Name = "vault-dynamodb-table" Environment = "prod" } } ``` If a table with the configured name already exists, Vault will not modify it - and the Vault configuration values of `read_capacity` and `write_capacity` have no effect. If the table does not already exist, Vault will try to create it, with read and write capacities set to the values of `read_capacity` and `write_capacity` respectively. ## DynamoDB Examples of Vault Configuration ### Custom Table and Read-Write Capacity This example shows using a custom table name and read/write capacity. ```hcl storage "dynamodb" { table = "my-vault-data" read_capacity = 10 write_capacity = 15 } ``` ### Enabling High Availability This example show enabling high availability for the DynamoDB storage backend. ```hcl api_addr = "https://vault-leader.my-company.internal" storage "dynamodb" { ha_enabled = "true" ... } ``` [dynamodb]: https://aws.amazon.com/dynamodb/ [dynamodb-rw-capacity]: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.html#ProvisionedThroughput