Plugins: Refactor Plugin Management (#40477)

* add core plugin flow

* add instrumentation

* move func

* remove cruft

* support external backend plugins

* refactor + clean up

* remove comments

* refactor loader

* simplify core plugin path arg

* cleanup loggers

* move signature validator to plugins package

* fix sig packaging

* cleanup plugin model

* remove unnecessary plugin field

* add start+stop for pm

* fix failures

* add decommissioned state

* export fields just to get things flowing

* fix comments

* set static routes

* make image loading idempotent

* merge with backend plugin manager

* re-use funcs

* reorder imports + remove unnecessary interface

* add some TODOs + remove unused func

* remove unused instrumentation func

* simplify client usage

* remove import alias

* re-use backendplugin.Plugin interface

* re order funcs

* improve var name

* fix log statements

* refactor data model

* add logic for dupe check during loading

* cleanup state setting

* refactor loader

* cleanup manager interface

* add rendering flow

* refactor loading + init

* add renderer support

* fix renderer plugin

* reformat imports

* track errors

* fix plugin signature inheritance

* name param in interface

* update func comment

* fix func arg name

* introduce class concept

* remove func

* fix external plugin check

* apply changes from pm-experiment

* fix core plugins

* fix imports

* rename interface

* comment API interface

* add support for testdata plugin

* enable alerting + use correct core plugin contracts

* slim manager API

* fix param name

* fix filter

* support static routes

* fix rendering

* tidy rendering

* get tests compiling

* fix install+uninstall

* start finder test

* add finder test coverage

* start loader tests

* add test for core plugins

* load core + bundled test

* add test for nested plugin loading

* add test files

* clean interface + fix registering some core plugins

* refactoring

* reformat and create sub packages

* simplify core plugin init

* fix ctx cancel scenario

* migrate initializer

* remove Init() funcs

* add test starter

* new logger

* flesh out initializer tests

* refactoring

* remove unused svc

* refactor rendering flow

* fixup loader tests

* add enabled helper func

* fix logger name

* fix data fetchers

* fix case where plugin dir doesn't exist

* improve coverage + move dupe checking to loader

* remove noisy debug logs

* register core plugins automagically

* add support for renderer in catalog

* make private func + fix req validation

* use interface

* re-add check for renderer in catalog

* tidy up from moving to auto reg core plugins

* core plugin registrar

* guards

* copy over core plugins for test infra

* all tests green

* renames

* propagate new interfaces

* kill old manager

* get compiling

* tidy up

* update naming

* refactor manager test + cleanup

* add more cases to finder test

* migrate validator to field

* more coverage

* refactor dupe checking

* add test for plugin class

* add coverage for initializer

* split out rendering

* move

* fixup tests

* fix uss test

* fix frontend settings

* fix grafanads test

* add check when checking sig errors

* fix enabled map

* fixup

* allow manual setup of CM

* rename to cloud-monitoring

* remove TODO

* add installer interface for testing

* loader interface returns

* tests passing

* refactor + add more coverage

* support 'stackdriver'

* fix frontend settings loading

* improve naming based on package name

* small tidy

* refactor test

* fix renderer start

* make cloud-monitoring plugin ID clearer

* add plugin update test

* add integration tests

* don't break all if sig can't be calculated

* add root URL check test

* add more signature verification tests

* update DTO name

* update enabled plugins comment

* update comments

* fix linter

* revert fe naming change

* fix errors endpoint

* reset error code field name

* re-order test to help verify

* assert -> require

* pm check

* add missing entry + re-order

* re-check

* dump icon log

* verify manager contents first

* reformat

* apply PR feedback

* apply style changes

* fix one vs all loading err

* improve log output

* only start when no signature error

* move log

* rework plugin update check

* fix test

* fix multi loading from cfg.PluginSettings

* improve log output #2

* add error abstraction to capture errors without registering a plugin

* add debug log

* add unsigned warning

* e2e test attempt

* fix logger

* set home path

* prevent panic

* alternate

* ugh.. fix home path

* return renderer even if not started

* make renderer plugin managed

* add fallback renderer icon, update renderer badge + prevent changes when renderer is installed

* fix icon loading

* rollback renderer changes

* use correct field

* remove unneccessary block

* remove newline

* remove unused func

* fix bundled plugins base + module fields

* remove unused field since refactor

* add authorizer abstraction

* loader only returns plugins expected to run

* fix multi log output

pkg/tsdb/cloudmonitoring/cloudmonitoring.go

@@ -26,7 +26,6 @@ import (
 	"github.com/grafana/grafana/pkg/infra/httpclient"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/plugins"
-	"github.com/grafana/grafana/pkg/plugins/backendplugin"
 	"github.com/grafana/grafana/pkg/plugins/backendplugin/coreplugin"
 	"github.com/grafana/grafana/pkg/services/datasources"
 
@@ -62,7 +61,7 @@ var (
 )
 
 const (
-	dsName = "stackdriver"
+	pluginID string = "stackdriver"
 
 	gceAuthentication         string = "gce"
 	jwtAuthentication         string = "jwt"
@@ -73,34 +72,30 @@ const (
 	perSeriesAlignerDefault   string = "ALIGN_MEAN"
 )
 
-func ProvideService(cfg *setting.Cfg, httpClientProvider httpclient.Provider, pluginManager plugins.Manager,
-	backendPluginManager backendplugin.Manager, dsService *datasources.Service) *Service {
+func ProvideService(cfg *setting.Cfg, httpClientProvider httpclient.Provider, registrar plugins.CoreBackendRegistrar,
+	dsService *datasources.Service) *Service {
 	s := &Service{
-		pluginManager:        pluginManager,
-		backendPluginManager: backendPluginManager,
-		httpClientProvider:   httpClientProvider,
-		cfg:                  cfg,
-		im:                   datasource.NewInstanceManager(newInstanceSettings(httpClientProvider)),
-		dsService:            dsService,
+		httpClientProvider: httpClientProvider,
+		cfg:                cfg,
+		im:                 datasource.NewInstanceManager(newInstanceSettings(httpClientProvider)),
+		dsService:          dsService,
 	}
 
 	factory := coreplugin.New(backend.ServeOpts{
 		QueryDataHandler: s,
 	})
 
-	if err := s.backendPluginManager.Register(dsName, factory); err != nil {
+	if err := registrar.LoadAndRegister(pluginID, factory); err != nil {
 		slog.Error("Failed to register plugin", "error", err)
 	}
 	return s
 }
 
 type Service struct {
-	pluginManager        plugins.Manager
-	backendPluginManager backendplugin.Manager
-	httpClientProvider   httpclient.Provider
-	cfg                  *setting.Cfg
-	im                   instancemgmt.InstanceManager
-	dsService            *datasources.Service
+	httpClientProvider httpclient.Provider
+	cfg                *setting.Cfg
+	im                 instancemgmt.InstanceManager
+	dsService          *datasources.Service
 }
 
 type QueryModel struct {
@@ -173,9 +168,8 @@ func newInstanceSettings(httpClientProvider httpclient.Provider) datasource.Inst
 	}
 }
 
-// Query takes in the frontend queries, parses them into the CloudMonitoring query format
-// executes the queries against the CloudMonitoring API and parses the response into
-// the data frames
+// QueryData takes in the frontend queries, parses them into the CloudMonitoring query format
+// executes the queries against the CloudMonitoring API and parses the response into data frames
 func (s *Service) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
 	resp := backend.NewQueryDataResponse()
 	if len(req.Queries) == 0 {
@@ -571,7 +565,7 @@ func calcBucketBound(bucketOptions cloudMonitoringBucketOptions, n int) string {
 	return bucketBound
 }
 
-func (s *Service) createRequest(ctx context.Context, pluginCtx backend.PluginContext, dsInfo *datasourceInfo, proxyPass string, body io.Reader) (*http.Request, error) {
+func (s *Service) createRequest(ctx context.Context, dsInfo *datasourceInfo, proxyPass string, body io.Reader) (*http.Request, error) {
 	u, err := url.Parse(dsInfo.url)
 	if err != nil {
 		return nil, err