Backend plugin system (#2874)

* 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

command/auth_enable.go

@@ -14,11 +14,12 @@ type AuthEnableCommand struct {
 }
 
 func (c *AuthEnableCommand) Run(args []string) int {
-	var description, path string
+	var description, path, pluginName string
 	var local bool
 	flags := c.Meta.FlagSet("auth-enable", meta.FlagSetDefault)
 	flags.StringVar(&description, "description", "", "")
 	flags.StringVar(&path, "path", "", "")
+	flags.StringVar(&pluginName, "plugin-name", "", "")
 	flags.BoolVar(&local, "local", false, "")
 	flags.Usage = func() { c.Ui.Error(c.Help()) }
 	if err := flags.Parse(args); err != nil {
@@ -36,8 +37,13 @@ func (c *AuthEnableCommand) Run(args []string) int {
 	authType := args[0]
 
 	// If no path is specified, we default the path to the backend type
+	// or use the plugin name if it's a plugin backend
 	if path == "" {
-		path = authType
+		if authType == "plugin" {
+			path = pluginName
+		} else {
+			path = authType
+		}
 	}
 
 	client, err := c.Client()
@@ -50,6 +56,7 @@ func (c *AuthEnableCommand) Run(args []string) int {
 	if err := client.Sys().EnableAuthWithOptions(path, &api.EnableAuthOptions{
 		Type:        authType,
 		Description: description,
+		PluginName:  pluginName,
 		Local:       local,
 	}); err != nil {
 		c.Ui.Error(fmt.Sprintf(
@@ -89,6 +96,9 @@ Auth Enable Options:
                           to the type of the mount. This will make the auth
                           provider available at "/auth/<path>"
 
+  -plugin-name            Name of the auth plugin to use based from the name 
+                          in the plugin catalog.
+
   -local                  Mark the mount as a local mount. Local mounts
                           are not replicated nor (if a secondary)
                           removed by replication.