Add plugin features

builtin/logical/database/dbs/credentialsproducer.go

@@ -11,7 +11,7 @@ import (
 type CredentialsProducer interface {
 	GenerateUsername(displayName string) (string, error)
 	GeneratePassword() (string, error)
-	GenerateExpiration(ttl time.Duration) string
+	GenerateExpiration(ttl time.Duration) (string, error)
 }
 
 // sqlCredentialsProducer impliments CredentialsProducer and provides a generic credentials producer for most sql database types.
@@ -46,10 +46,10 @@ func (scp *sqlCredentialsProducer) GeneratePassword() (string, error) {
 	return password, nil
 }
 
-func (scp *sqlCredentialsProducer) GenerateExpiration(ttl time.Duration) string {
+func (scp *sqlCredentialsProducer) GenerateExpiration(ttl time.Duration) (string, error) {
 	return time.Now().
 		Add(ttl).
-		Format("2006-01-02 15:04:05-0700")
+		Format("2006-01-02 15:04:05-0700"), nil
 }
 
 type cassandraCredentialsProducer struct{}
@@ -74,6 +74,6 @@ func (ccp *cassandraCredentialsProducer) GeneratePassword() (string, error) {
 	return password, nil
 }
 
-func (ccp *cassandraCredentialsProducer) GenerateExpiration(ttl time.Duration) string {
+func (ccp *cassandraCredentialsProducer) GenerateExpiration(ttl time.Duration) (string, error) {
-	return ""
+	return "", nil
 }

builtin/logical/database/dbs/db.go

@@ -13,6 +13,7 @@ const (
 	postgreSQLTypeName = "postgres"
 	mySQLTypeName      = "mysql"
 	cassandraTypeName  = "cassandra"
+	pluginTypeName     = "plugin"
 )
 
 var (
@@ -71,6 +72,18 @@ func Factory(conf *DatabaseConfig) (DatabaseType, error) {
 			ConnectionProducer:  connProducer,
 			CredentialsProducer: credsProducer,
 		}, nil
+
+	case pluginTypeName:
+		if conf.PluginCommand == "" {
+			return nil, errors.New("ERROR")
+		}
+
+		db, err := newPluginClient(conf.PluginCommand)
+		if err != nil {
+			return nil, err
+		}
+
+		return db, nil
 	}
 
 	return nil, ErrUnsupportedDatabaseType
@@ -82,7 +95,7 @@ type DatabaseType interface {
 	RenewUser(statements Statements, username, expiration string) error
 	RevokeUser(statements Statements, username string) error
 
-	ConnectionProducer
+	Close()
 	CredentialsProducer
 }
 
@@ -92,6 +105,7 @@ type DatabaseConfig struct {
 	MaxOpenConnections    int                    `json:"max_open_connections" structs:"max_open_connections" mapstructure:"max_open_connections"`
 	MaxIdleConnections    int                    `json:"max_idle_connections" structs:"max_idle_connections" mapstructure:"max_idle_connections"`
 	MaxConnectionLifetime time.Duration          `json:"max_connection_lifetime" structs:"max_connection_lifetime" mapstructure:"max_connection_lifetime"`
+	PluginCommand         string                 `json:"plugin_command" structs:"plugin_command" mapstructure:"plugin_command"`
 }
 
 // Statments set in role creation and passed into the database type's functions.

builtin/logical/database/path_config_connection.go

@@ -111,6 +111,12 @@ reduced to the same size.`,
 				Description: `Maximum amount of time a connection may be reused;
 				a zero or negative value reuses connections forever.`,
 			},
+
+			"plugin_command": &framework.FieldSchema{
+				Type: framework.TypeString,
+				Description: `Maximum amount of time a connection may be reused;
+				a zero or negative value reuses connections forever.`,
+			},
 		},
 
 		Callbacks: map[logical.Operation]framework.OperationFunc{
@@ -146,6 +152,9 @@ func (b *databaseBackend) pathConnectionRead(req *logical.Request, data *framewo
 
 func (b *databaseBackend) pathConnectionWrite(req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
 	connType := data.Get("connection_type").(string)
+	if connType == "" {
+		return logical.ErrorResponse("connection_type not set"), nil
+	}
 
 	maxOpenConns := data.Get("max_open_connections").(int)
 	if maxOpenConns == 0 {
@@ -173,6 +182,7 @@ func (b *databaseBackend) pathConnectionWrite(req *logical.Request, data *framew
 		MaxOpenConnections:    maxOpenConns,
 		MaxIdleConnections:    maxIdleConns,
 		MaxConnectionLifetime: maxConnLifetime,
+		PluginCommand:         data.Get("plugin_command").(string),
 	}
 
 	name := data.Get("name").(string)

builtin/logical/database/path_role_create.go

@@ -65,7 +65,10 @@ func (b *databaseBackend) pathRoleCreateRead(req *logical.Request, data *framewo
 		return nil, err
 	}
 
-	expiration := db.GenerateExpiration(role.DefaultTTL)
+	expiration, err := db.GenerateExpiration(role.DefaultTTL)
+	if err != nil {
+		return nil, err
+	}
 
 	err = db.CreateUser(role.Statements, username, password, expiration)
 	if err != nil {