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Plugin system

OpenBao supports 3 types of plugins; auth methods, secret engines, and database plugins. This concept allows both built-in and external plugins to be treated like building blocks. Any plugin can exist at multiple different mount paths. Different versions of a plugin may be at each location, with each version differing from OpenBao's version.

A plugin is uniquely identified by its type (one of secret, auth, or database), name (e.g. kv), and version (e.g v1.0.0). An empty version implies either the built-in plugin or the single unversioned plugin that can be registered.

See Plugin Upgrade Procedure for details on how to upgrade a built-in plugin in-place.

Built-In plugins​

Built-in plugins are shipped with OpenBao, often for commonly used integrations, and can be used without any prerequisite steps.

External plugins​

External plugins are not shipped with OpenBao and require additional operator intervention to run.

To run an external plugin, a binary of the plugin is required. Plugin binaries can be obtained from releases.hashicorp.com or they can be built from source.

OpenBao's external plugins are completely separate, standalone applications that OpenBao executes and communicates with over RPC. Each time an OpenBao secret engine, auth method, or database plugin is mounted, a new process is spawned. However, plugins can be made to implement plugin multiplexing to improve performance. Plugin multiplexing allows plugin processes to be reused across all mounts of a given type.

info

NOTE: See the OpenBao Integrations page to find a curated collection of official, partner, and community OpenBao plugins.

Plugin versioning​

OpenBao supports managing, running and upgrading plugins using semantic version information.

The plugin catalog optionally supports specifying a semantic version when registering an external plugin. Multiple versions of a plugin can be registered in the catalog simultaneously, and a version can be selected when mounting a plugin or tuning an existing mount in-place.

If no version is specified when creating a new mount, the following precedence is used for any available plugins whose type and name match:

  • The plugin registered with no version
  • The plugin with the most recent semantic version among any registered versions
  • The plugin built into OpenBao

Built-In versions​

OpenBao will report a version for built-in plugins to indicate what version of the plugin code got built into OpenBao as a dependency. For example:

$ bao plugin list secret
Name                Version
----                -------
kubernetes      v0.5.0+builtin
kv              v0.15.0+builtin
ldap            v1.14.8+builtin.openbao
openldap        v0.11.1+builtin
pki             v1.14.8+builtin.openbao
rabbitmq        v1.14.8+builtin.openbao
ssh             v1.14.8+builtin.openbao
totp            v1.14.8+builtin.openbao
transit         v1.14.8+builtin.openbao

Here, OpenBao has a dependency on v0.15.0 of the openbao-plugin-secrets-kv repo, and the openbao metadata identifier for pki indicates that plugin's code was within the OpenBao repo. For plugins within the OpenBao repo, OpenBao's own major, minor, and patch versions are used to form the plugin version.

The builtin metadata identifier is reserved and cannot be used when registering external plugins.