MySQL/MariaDB database secrets engine

MySQL is one of the supported plugins for the database secrets engine. This plugin generates database credentials dynamically based on configured roles for the MySQL database, and also supports Static Roles.

This plugin has a few different instances built into vault, each instance is for a slightly different MySQL driver. The only difference between these plugins is the length of usernames generated by the plugin as different versions of mysql accept different lengths. The available plugins are:

• mysql-database-plugin
• mysql-aurora-database-plugin
• mysql-rds-database-plugin
• mysql-legacy-database-plugin

See the database secrets engine docs for more information about setting up the database secrets engine.

Capabilities

Setup

1. Enable the database secrets engine if it is not already enabled:

   $ vault secrets enable database
   Success! Enabled the database secrets engine at: database/
   

   By default, the secrets engine will enable at the name of the engine. To enable the secrets engine at a different path, use the -path argument.

2. Configure Vault with the proper plugin and connection information:

   $ vault write database/config/my-mysql-database \
       plugin_name=mysql-database-plugin \
       connection_url="{{username}}:{{password}}@tcp(127.0.0.1:3306)/" \
       allowed_roles="my-role" \
       username="vaultuser" \
       password="vaultpass"
   

3. Configure a role that maps a name in Vault to an SQL statement to execute to create the database credential:

   $ vault write database/roles/my-role \
       db_name=my-mysql-database \
       creation_statements="CREATE USER '{{name}}'@'%' IDENTIFIED BY '{{password}}';GRANT SELECT ON *.* TO '{{name}}'@'%';" \
       default_ttl="1h" \
       max_ttl="24h"
   Success! Data written to: database/roles/my-role
   

Usage

After the secrets engine is configured and a user/machine has a Vault token with the proper permission, it can generate credentials.

1. Generate a new credential by reading from the /creds endpoint with the name of the role:

   $ vault read database/creds/my-role
   Key                Value
   ---                -----
   lease_id           database/creds/my-role/2f6a614c-4aa2-7b19-24b9-ad944a8d4de6
   lease_duration     1h
   lease_renewable    true
   password           yY-57n3X5UQhxnmFRP3f
   username           v_vaultuser_my-role_crBWVqVh2Hc1
   

Client x509 certificate authentication

This plugin supports using MySQL's x509 Client-side Certificate Authentication

To use this authentication mechanism, configure the plugin:

$ vault write database/config/my-mysql-database \
    plugin_name=mysql-database-plugin \
    allowed_roles="my-role" \
    connection_url="user:password@tcp(localhost:3306)/test" \
    tls_certificate_key=@/path/to/client.pem \
    tls_ca=@/path/to/client.ca

Note: tls_certificate_key and tls_ca map to ssl-cert (combined with ssl-key) and ssl-ca configuration options from MySQL with the exception that the Vault parameters are the contents of those files, not filenames. As such, the two options are independent of each other. See the MySQL Connection Options for more information.

Examples

Using wildcards in grant statements

MySQL supports using wildcards in grant statements. These are sometimes needed by applications which expect access to a large number of databases inside MySQL. This can be realized by using a wildcard in the grant statement. For example if you want the user created by Vault to have access to all databases starting with fooapp_ you could use the following creation statement:

CREATE USER '{{name}}'@'%' IDENTIFIED BY '{{password}}'; GRANT SELECT ON `fooapp\_%`.* TO '{{name}}'@'%';

MySQL expects the part in which the wildcards are to be placed inside backticks. If you want to add this creation statement to Vault via the Vault CLI you cannot simply paste the above statement on the CLI because the shell will interpret the text between the backticks as something that must be executed. The easiest way to get around this is to encode the creation statement as Base64 and feed this to Vault. For example:

$ vault write database/roles/my-role \
    db_name=mysql \
    creation_statements="Q1JFQVRFIFVTRVIgJ3t7bmFtZX19J0AnJScgSURFTlRJRklFRCBCWSAne3twYXNzd29yZH19JzsgR1JBTlQgU0VMRUNUIE9OIGBmb29hcHBcXyVgLiogVE8gJ3t7bmFtZX19J0AnJSc7" \
    default_ttl="1h" \
    max_ttl="24h"

Rotating root credentials in MySQL 5.6

The default root rotation setup for MySQL uses the ALTER USER syntax present in MySQL 5.7 and up. For MySQL 5.6, the root rotation statements must be configured to use the old SET PASSWORD syntax. For example:

$ vault write database/config/my-mysql-database \
    plugin_name=mysql-database-plugin \
    connection_url="{{username}}:{{password}}@tcp(127.0.0.1:3306)/" \
    root_rotation_statements="SET PASSWORD = PASSWORD('{{password}}')" \
    allowed_roles="my-role" \
    username="root" \
    password="mysql"

For a guide in root credential rotation, see Database Root Credential Rotation.

API

The full list of configurable options can be seen in the MySQL database plugin API page.

For more information on the database secrets engine's HTTP API please see the Database secrets engine API page.

Authenticating to Cloud DBs via IAM

Google Cloud

Aside from IAM roles denoted by Google's CloudSQL documentation, the following SQL privileges are needed by the service account's DB user for minimum functionality with Vault. Additional privileges may be needed depending on the SQL configured on the database roles.

-- Enable service account to create users within DB
GRANT SELECT, CREATE, CREATE USER ON <database>.<object> TO "test-user"@"%" WITH GRANT OPTION;

Setup

1. Enable the database secrets engine if it is not already enabled:

   $ vault secrets enable database
   Success! Enabled the database secrets engine at: database/
   

   By default, the secrets engine will enable at the name of the engine. To enable the secrets engine at a different path, use the -path argument.

2. Configure Vault with the proper plugin and connection information. Here you can explicitly enable GCP IAM authentication and use Application Default Credentials to authenticate.

   Note: For Google Cloud IAM, the Protocol is cloudsql-mysql instead of tcp.

   $ vault write database/config/my-mysql-database \
       plugin_name="mysql-database-plugin" \
       allowed_roles="my-role" \
       connection_url="user@cloudsql-mysql(project:region:instance)/mysql" \
       auth_type="gcp_iam"
   

   You can also configure the connection and authenticate by directly passing in the service account credentials as an encoded JSON string:

   $ vault write database/config/my-mysql-database \
       plugin_name="mysql-database-plugin" \
       allowed_roles="my-role" \
       connection_url="user@cloudsql-mysql(project:region:instance)/mysql" \
       auth_type="gcp_iam" \
       service_account_json="@my_credentials.json"
   

3. Configure a new role in Vault but override the default revocation statements so Vault will drop the user instead:

      $ vault write database/roles/my-role \
          db_name=my-mysql-database \
          creation_statements="CREATE USER '{{name}}'@'%' IDENTIFIED BY '{{password}}';GRANT SELECT ON *.* TO '{{name}}'@'%';" \
          revocation_statements="DROP USER '{{name}}'@'%';" \
          default_ttl="1h" \
          max_ttl="24h"
   

4. When you finish configuring the new role, generate credentials as before:

      $ vault read database/creds/my-role
      Key                Value
      ---                -----
      lease_id           database/creds/my-role/2f6b629f-7ah2-7b19-24b9-ad879a8d4bf2
      lease_duration     1h
      lease_renewable    true
      password           vY-57n3X5UQhxnmGTK7g
      username           v_vaultuser_my-role_frBYNfYh3Kw3