vault/website/content/docs/secrets/databases/postgresql.mdx

---
layout: docs
page_title: PostgreSQL - Database - Secrets Engines
description: |-
  PostgreSQL is one of the supported plugins for the database secrets engine.
  This plugin generates database credentials dynamically based on configured
  roles for the PostgreSQL database.
---

# PostgreSQL database secrets engine

PostgreSQL is one of the supported plugins for the database secrets engine. This
plugin generates database credentials dynamically based on configured roles for
the PostgreSQL database, and also supports [Static
Roles](/vault/docs/secrets/databases#static-roles).

See the [database secrets engine](/vault/docs/secrets/databases) docs for
more information about setting up the database secrets engine.

The PostgreSQL secrets engine uses [pgx][pgxlib], the same database library as the
[PostgreSQL storage backend](/vault/docs/configuration/storage/postgresql). Connection string
options, including SSL options, can be found in the [pgx][pgxlib] and
[PostgreSQL connection string][pg_conn_docs] documentation.

## Capabilities

| Plugin Name                  | Root Credential Rotation | Dynamic Roles | Static Roles | Username Customization | Credential Types             |
| ---------------------------- | ------------------------ | ------------- | ------------ | ---------------------- | ---------------------------- |
| `postgresql-database-plugin` | Yes                      | Yes           | Yes          | Yes (1.7+)             | password, gcp_iam            |

## Setup

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

    ```shell-session
    $ 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.

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

    ```shell-session
    $ vault write database/config/my-postgresql-database \
        plugin_name="postgresql-database-plugin" \
        allowed_roles="my-role" \
        connection_url="postgresql://{{username}}:{{password}}@localhost:5432/database-name" \
        username="vaultuser" \
        password="vaultpass" \
        password_authentication="scram-sha-256"
    ```

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

    ```shell-session
    $ vault write database/roles/my-role \
        db_name="my-postgresql-database" \
        creation_statements="CREATE ROLE \"{{name}}\" WITH LOGIN PASSWORD '{{password}}' VALID UNTIL '{{expiration}}'; \
            GRANT SELECT ON ALL TABLES IN SCHEMA public 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:

    ```shell-session
    $ 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           SsnoaA-8Tv4t34f41baD
    username           v-vaultuse-my-role-x
    ```

## Rootless Configuration and Password Rotation for Static Roles

<EnterpriseAlert product="vault" />

The PostgreSQL secrets engine supports using Static Roles and its password rotation mechanisms with a Rootless
DB connection configuration. In this workflow, a static DB user can be onboarded onto Vault's static role rotation
mechanism without the need of privileged root accounts to configure the connection. Instead of using a single root
connection, multiple dedicated connections to the DB are made for each static role. This workflow does not support
dynamic roles/credentials.

~> Note: It is **highly recommended** that the DB users being onboarded as static roles
have the minimum set of privileges. Each static role will open a new connection into the DB.
Granting minimum privileges to the DB users being onboarded ensures that multiple
highly-privileged connections to an external system are not being made.

~> Note: Out-of-band password rotations will cause Vault to be out of sync with the state of
the DB user, and will require manually updating the user's password in the external PostgreSQL
DB in order to resolve any errors encountered during rotation.

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

    ```shell-session
    $ 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.

1.  Configure connection to DB without root credentials and enable the rootless
    workflow by setting the `self_managed` parameter:

    ```shell-session
    $ vault write database/config/my-postgresql-database \
        plugin_name="postgresql-database-plugin" \
        allowed_roles="my-role" \
        connection_url="postgresql://{{username}}:{{password}}@localhost:5432/database-name" \
        self_managed=true
    ```

1.  Configure a static role that creates a dedicated connection to a user in the DB with
    the `self_managed_password` parameter:

    ```shell-session
    $ vault write database/static-roles/my-static-role \
      db_name="my-postgresql-database" \
      username="staticuser" \
      self_managed_password="password" \
      rotation_period="1h"
    ```

1.  Read static credentials:

    ```shell-session
    $ vault read database/static-creds/static-test
    Key                    Value
    ---                    -----
    last_vault_rotation    2024-09-11T14:15:13.764783-07:00
    password               XZY42BVc-UO5bMsbgxrW
    rotation_period        1h
    ttl                    59m55s
    username               staticuser
    ```

## Client x509 certificate authentication

This plugin supports using PostgreSQl's [x509 Client-side Certificate Authentication](https://www.postgresql.org/docs/16/libpq-ssl.html#LIBPQ-SSL-CLIENTCERT).

To use this authentication mechanism, configure the plugin to consume the
PEM-encoded TLS data inline from a file on disk by prefixing with the "@"
symbol. This is useful in environments where you do not have direct access to
the machine that is hosting the Vault server. For example:

```shell-session
$ vault write database/config/my-postgresql-database \
    plugin_name="postgresql-database-plugin" \
    allowed_roles="my-role" \
    connection_url="postgresql://{{username}}:{{password}}@localhost:5432/database-name?sslmode=verify-full" \
    username="vaultuser" \
    private_key=@/path/to/client.key \
    tls_certificate=@/path/to/client.pem \
    tls_ca=@/path/to/client.ca
```

Note: `private_key`, `tls_certificate`, and `tls_ca` map to [`sslkey`][sslkey_docs],
[`sslcert`][sslcert_docs], and [`sslrootcert`][sslrootcert_docs] configuration
options from PostgreSQL with the exception that the Vault parameters are the
contents of those files, not filenames.

[sslkey_docs]: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY
[sslcert_docs]: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT
[sslrootcert_docs]: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT

Alternatively, you can configure certificate authentication in environments
where the TLS certificate data is present on the machine that is running the
Vault server process. Set `sslmode` to be any of the applicable values as
outlined in the PostgreSQL documentation and set the SSL credentials in the
`sslrootcert`, `sslcert` and `sslkey` connection parameters as paths to files.
For example:

```shell-session
$ export SSL="sslmode=verify-full&sslrootcert=/path/to/ca.pem&sslcert=/path/to/client.pem&sslkey=/path/to/client.key"
$ vault write database/config/my-postgresql-database \
    plugin_name="postgresql-database-plugin" \
    allowed_roles="my-role" \
    connection_url="postgresql://{{username}}:{{password}}@localhost:5432/database-name?sslmode=verify-full&${SSL}" \
    username="vaultuser"
```

## API

The full list of configurable options can be seen in the [PostgreSQL database
plugin API](/vault/api-docs/secret/databases/postgresql) page.

For more information on the database secrets engine's HTTP API please see the
[Database secrets engine API](/vault/api-docs/secret/databases) page.

[pgxlib]: https://pkg.go.dev/github.com/jackc/pgx/stdlib
[pg_conn_docs]: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING

## Authenticating to Cloud DBs via IAM

### Google Cloud

Aside from IAM roles denoted by [Google's CloudSQL documentation](https://cloud.google.com/sql/docs/postgres/add-manage-iam-users#creating-a-database-user),
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.

```sql
-- Enable service account to create roles within DB
ALTER USER "<YOUR DB USERNAME>" WITH CREATEROLE;
```

### Setup

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

    ```shell-session
    $ 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.

1.  Configure Vault with the proper plugin and connection information. Here you can explicitly enable GCP IAM authentication
    and use [Application Default Credentials](https://cloud.google.com/docs/authentication/provide-credentials-adc#how-to) to authenticate:

    ```shell-session
    $ vault write database/config/my-postgresql-database \
        plugin_name="postgresql-database-plugin" \
        allowed_roles="my-role" \
        connection_url="host=project:us-west1:mydb user=test-user@project.iam dbname=postgres sslmode=disable" \
        use_private_ip="false" \
        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:

    ```shell-session
    $ vault write database/config/my-postgresql-database \
        plugin_name="postgresql-database-plugin" \
        allowed_roles="my-role" \
        connection_url="host=project:region:instance user=test-user@project.iam dbname=postgres sslmode=disable" \
        use_private_ip="false" \
        auth_type="gcp_iam" \
        service_account_json="@my_credentials.json"
    ```

Once the connection has been configured and IAM authentication is complete, the steps to set up a role and generate
credentials are the same as the ones listed above.