External plugins are the components in Vault that can be implemented separately from Vault's built-in plugins. These plugins can be either authentication or secrets engines.
api_addr must be set in order for the plugin process to
establish communication with the Vault server during mount time. If the storage
backend has HA enabled and supports automatic host address detection (e.g.
Consul), Vault will automatically attempt to determine the
api_addr as well.
Detailed information regarding the plugin system can be found in the internals documentation.
Before an external plugin can be mounted, it needs to be registered in the plugin catalog to ensure the plugin invoked by Vault is authentic and maintains integrity:
$ vault plugin register -sha256=<SHA256 Hex value of the plugin binary> \ secret \ # type passthrough-plugin Success! Registered plugin: passthrough-plugin
After the plugin is registered, it can be mounted by specifying the registered plugin name:
$ vault secrets enable -path=my-secrets passthrough-plugin Success! Enabled the passthrough-plugin secrets engine at: my-secrets/
Listing secrets engines will display secrets engines that are mounted as plugins:
$ vault secrets list Path Type Accessor Plugin Default TTL Max TTL Force No Cache Replication Behavior Description my-secrets/ plugin plugin_deb84140 passthrough-plugin system system false replicated
Disabling an external plugins is identical to disabling a built-in plugin:
$ vault secrets disable my-secrets
Upgrade instructions can be found in the Upgrading Plugins - Guides page.