Add usePrivateIP for cloudsql postgresql instances

changelog/26828.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+secrets/database: Add support for GCP CloudSQL private IP's.
+```

plugins/database/mysql/connection_producer.go

@@ -322,7 +322,7 @@ func (c *mySQLConnectionProducer) rewriteProtocolForGCP(inDSN string) (string, e
 }
 
 func registerDriverMySQL(driverName, credentials string) (cleanup func() error, err error) {
-	opts, err := connutil.GetCloudSQLAuthOptions(credentials)
+	opts, err := connutil.GetCloudSQLAuthOptions(credentials, false)
 	if err != nil {
 		return nil, err
 	}

sdk/database/helper/connutil/cloudsql.go

@@ -27,13 +27,13 @@ func (c *SQLConnectionProducer) getCloudSQLDriverType() (string, error) {
 	return driverType, nil
 }
 
-func (c *SQLConnectionProducer) registerDrivers(driverName string, credentials string) (func() error, error) {
+func (c *SQLConnectionProducer) registerDrivers(driverName string, credentials string, usePrivateIP bool) (func() error, error) {
 	typ, err := c.getCloudSQLDriverType()
 	if err != nil {
 		return nil, err
 	}
 
-	opts, err := GetCloudSQLAuthOptions(credentials)
+	opts, err := GetCloudSQLAuthOptions(credentials, usePrivateIP)
 	if err != nil {
 		return nil, err
 	}
@@ -49,13 +49,17 @@ func (c *SQLConnectionProducer) registerDrivers(driverName string, credentials s
 
 // GetCloudSQLAuthOptions takes a credentials JSON and returns
 // a set of GCP CloudSQL options - always WithIAMAUthN, and then the appropriate file/JSON option.
-func GetCloudSQLAuthOptions(credentials string) ([]cloudsqlconn.Option, error) {
+func GetCloudSQLAuthOptions(credentials string, usePrivateIP bool) ([]cloudsqlconn.Option, error) {
 	opts := []cloudsqlconn.Option{cloudsqlconn.WithIAMAuthN()}
 
 	if credentials != "" {
 		opts = append(opts, cloudsqlconn.WithCredentialsJSON([]byte(credentials)))
 	}
 
+	if usePrivateIP {
+		opts = append(opts, cloudsqlconn.WithDefaultDialOptions(cloudsqlconn.WithPrivateIP()))
+	}
+
 	return opts, nil
 }
 

sdk/database/helper/connutil/sql.go

@@ -40,6 +40,7 @@ type SQLConnectionProducer struct {
 	AuthType                 string      `json:"auth_type" mapstructure:"auth_type" structs:"auth_type"`
 	ServiceAccountJSON       string      `json:"service_account_json" mapstructure:"service_account_json" structs:"service_account_json"`
 	DisableEscaping          bool        `json:"disable_escaping" mapstructure:"disable_escaping" structs:"disable_escaping"`
+	usePrivateIP             bool        `json:"use_private_ip" mapstructure:"use_private_ip" structs:"use_private_ip"`
 
 	// cloud options here - cloudDriverName is globally unique, but only needs to be retained for the lifetime
 	// of driver registration, not across plugin restarts.
@@ -140,7 +141,7 @@ func (c *SQLConnectionProducer) Init(ctx context.Context, conf map[string]interf
 		// however, the driver might store a credentials file, in which case the state stored by the driver is in
 		// fact critical to the proper function of the connection. So it needs to be registered here inside the
 		// ConnectionProducer init.
-		dialerCleanup, err := c.registerDrivers(c.cloudDriverName, c.ServiceAccountJSON)
+		dialerCleanup, err := c.registerDrivers(c.cloudDriverName, c.ServiceAccountJSON, c.usePrivateIp)
 		if err != nil {
 			return nil, err
 		}

website/content/api-docs/secret/databases/postgresql.mdx

@@ -58,6 +58,9 @@ has a number of parameters to further configure a connection.
 - `service_account_json` `(string: "")` - JSON encoded credentials for a GCP Service Account to use
   for IAM authentication. Requires `auth_type` to be `gcp_iam`.
 
+- `use_private_ip` `(boolean: false)` - Enables the option to connect to CloudSQL Instances with Private IP.
+   Requires `auth_type` to be `gcp_iam`.
+
 - `username_template` `(string)` - [Template](/vault/docs/concepts/username-templating) describing how
   dynamic usernames are generated.
 

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

@@ -128,6 +128,7 @@ ALTER USER "<YOUR DB USERNAME>" WITH CREATEROLE;
         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"
     ```
 
@@ -139,6 +140,7 @@ ALTER USER "<YOUR DB USERNAME>" WITH CREATEROLE;
         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"
     ```