* Add backend plugin changes
* Fix totp backend plugin tests
* Fix logical/plugin InvalidateKey test
* Fix plugin catalog CRUD test, fix NoopBackend
* Clean up commented code block
* Fix system backend mount test
* Set plugin_name to omitempty, fix handleMountTable config parsing
* Clean up comments, keep shim connections alive until cleanup
* Include pluginClient, disallow LookupPlugin call from within a plugin
* Add wrapper around backendPluginClient for proper cleanup
* Add logger shim tests
* Add logger, storage, and system shim tests
* Use pointer receivers for system view shim
* Use plugin name if no path is provided on mount
* Enable plugins for auth backends
* Add backend type attribute, move builtin/plugin/package
* Fix merge conflict
* Fix missing plugin name in mount config
* Add integration tests on enabling auth backend plugins
* Remove dependency cycle on mock-plugin
* Add passthrough backend plugin, use logical.BackendType to determine lease generation
* Remove vault package dependency on passthrough package
* Add basic impl test for passthrough plugin
* Incorporate feedback; set b.backend after shims creation on backendPluginServer
* Fix totp plugin test
* Add plugin backends docs
* Fix tests
* Fix builtin/plugin tests
* Remove flatten from PluginRunner fields
* Move mock plugin to logical/plugin, remove totp and passthrough plugins
* Move pluginMap into newPluginClient
* Do not create storage RPC connection on HandleRequest and HandleExistenceCheck
* Change shim logger's Fatal to no-op
* Change BackendType to uint32, match UX backend types
* Change framework.Backend Setup signature
* Add Setup func to logical.Backend interface
* Move OptionallyEnableMlock call into plugin.Serve, update docs and comments
* Remove commented var in plugin package
* RegisterLicense on logical.Backend interface (#3017)
* Add RegisterLicense to logical.Backend interface
* Update RegisterLicense to use callback func on framework.Backend
* Refactor framework.Backend.RegisterLicense
* plugin: Prevent plugin.SystemViewClient.ResponseWrapData from getting JWTs
* plugin: Revert BackendType to remove TypePassthrough and related references
* Fix typo in plugin backends docs
1) Use the new LeaseExtend
2) Use default values controlled by mount tuning/system defaults instead
of a random hard coded value
3) Remove grace periods
Currently permissions are not revoked, which can lead revocation to not
actually work properly. This attempts to revoke all permissions and only
then drop the role.
Fixes issue #699
