# Understand Docker plugins You can extend the capabilities of the Docker Engine by loading third-party plugins. ## Types of plugins Plugins extend Docker's functionality. They come in specific types. For example, a [volume plugin](/extend/plugins_volume) might enable Docker volumes to persist across multiple Docker hosts. Currently Docker supports volume and network driver plugins. In the future it will support additional plugin types. ## Installing a plugin Follow the instructions in the plugin's documentation. ## Finding a plugin The following plugins exist: * The [Blockbridge plugin](https://github.com/blockbridge/blockbridge-docker-volume) is a volume plugin that provides access to an extensible set of container-based persistent storage options. It supports single and multi-host Docker environments with features that include tenant isolation, automated provisioning, encryption, secure deletion, snapshots and QoS. * The [Flocker plugin](https://clusterhq.com/docker-plugin/) is a volume plugin which provides multi-host portable volumes for Docker, enabling you to run databases and other stateful containers and move them around across a cluster of machines. * The [GlusterFS plugin](https://github.com/calavera/docker-volume-glusterfs) is another volume plugin that provides multi-host volumes management for Docker using GlusterFS. * The [Keywhiz plugin](https://github.com/calavera/docker-volume-keywhiz) is a plugin that provides credentials and secret management using Keywhiz as a central repository. * The [REX-Ray plugin](https://github.com/emccode/rexraycli) is a volume plugin which is written in Go and provides advanced storage functionality for many platforms including EC2, OpenStack, XtremIO, and ScaleIO. ## Troubleshooting a plugin If you are having problems with Docker after loading a plugin, ask the authors of the plugin for help. The Docker team may not be able to assist you. ## Writing a plugin If you are interested in writing a plugin for Docker, or seeing how they work under the hood, see the [docker plugins reference](/extend/plugin_api).