Plugins: Add inititialization stage to plugin loader pipeline (#72667)

* first pass

* migrate tests

* simplify

* fix comments

* fix linter

* nil checks

* remove comment

pkg/api/plugin_resource_test.go

@@ -73,11 +73,12 @@ func TestCallResource(t *testing.T) {
 
 	discovery := pipeline.ProvideDiscoveryStage(pCfg, finder.NewLocalFinder(pCfg.DevMode), reg)
 	bootstrap := pipeline.ProvideBootstrapStage(pCfg, signature.ProvideService(pCfg, statickey.New()), assetpath.ProvideService(pluginscdn.ProvideService(pCfg)))
+	initialize := pipeline.ProvideInitializationStage(pCfg, reg, fakes.NewFakeLicensingService(), provider.ProvideService(coreRegistry))
 
-	l := loader.ProvideService(pCfg, fakes.NewFakeLicensingService(), signature.NewUnsignedAuthorizer(pCfg),
-		reg, provider.ProvideService(coreRegistry), fakes.NewFakeRoleRegistry(),
+	l := loader.ProvideService(pCfg, signature.NewUnsignedAuthorizer(pCfg),
+		reg, fakes.NewFakeRoleRegistry(),
 		assetpath.ProvideService(pluginscdn.ProvideService(pCfg)),
-		angularInspector, &fakes.FakeOauthService{}, discovery, bootstrap)
+		angularInspector, &fakes.FakeOauthService{}, discovery, bootstrap, initialize)
 	srcs := sources.ProvideService(cfg, pCfg)
 	ps, err := store.ProvideService(reg, srcs, l)
 	require.NoError(t, err)

pkg/plugins/manager/fakes/fakes.go

@@ -463,3 +463,36 @@ func (pr *FakePluginStore) Plugins(_ context.Context, pluginTypes ...plugins.Typ
 
 	return result
 }
+
+type FakeDiscoverer struct {
+	DiscoverFunc func(ctx context.Context, src plugins.PluginSource) ([]*plugins.FoundBundle, error)
+}
+
+func (f *FakeDiscoverer) Discover(ctx context.Context, src plugins.PluginSource) ([]*plugins.FoundBundle, error) {
+	if f.DiscoverFunc != nil {
+		return f.DiscoverFunc(ctx, src)
+	}
+	return []*plugins.FoundBundle{}, nil
+}
+
+type FakeBootstrapper struct {
+	BootstrapFunc func(ctx context.Context, src plugins.PluginSource, bundles []*plugins.FoundBundle) ([]*plugins.Plugin, error)
+}
+
+func (f *FakeBootstrapper) Bootstrap(ctx context.Context, src plugins.PluginSource, bundles []*plugins.FoundBundle) ([]*plugins.Plugin, error) {
+	if f.BootstrapFunc != nil {
+		return f.BootstrapFunc(ctx, src, bundles)
+	}
+	return []*plugins.Plugin{}, nil
+}
+
+type FakeInitializer struct {
+	IntializeFunc func(ctx context.Context, ps []*plugins.Plugin) ([]*plugins.Plugin, error)
+}
+
+func (f *FakeInitializer) Initialize(ctx context.Context, ps []*plugins.Plugin) ([]*plugins.Plugin, error) {
+	if f.IntializeFunc != nil {
+		return f.IntializeFunc(ctx, ps)
+	}
+	return []*plugins.Plugin{}, nil
+}

pkg/plugins/manager/loader/initializer/initializer.go

@@ -1,43 +0,0 @@
-package initializer
-
-import (
-	"context"
-	"errors"
-
-	"github.com/grafana/grafana/pkg/plugins"
-	"github.com/grafana/grafana/pkg/plugins/config"
-	"github.com/grafana/grafana/pkg/plugins/envvars"
-)
-
-type Initializer struct {
-	envVarProvider  envvars.Provider
-	backendProvider plugins.BackendFactoryProvider
-}
-
-func New(cfg *config.Cfg, backendProvider plugins.BackendFactoryProvider, license plugins.Licensing) Initializer {
-	return Initializer{
-		envVarProvider:  envvars.NewProvider(cfg, license),
-		backendProvider: backendProvider,
-	}
-}
-
-func (i *Initializer) Initialize(ctx context.Context, p *plugins.Plugin) error {
-	if p.Backend {
-		backendFactory := i.backendProvider.BackendFactory(ctx, p)
-		if backendFactory == nil {
-			return errors.New("could not find backend factory for plugin")
-		}
-
-		env, err := i.envVarProvider.Get(ctx, p)
-		if err != nil {
-			return err
-		}
-		if backendClient, err := backendFactory(p.ID, p.Logger(), env); err != nil {
-			return err
-		} else {
-			p.RegisterClient(backendClient)
-		}
-	}
-
-	return nil
-}

pkg/plugins/manager/loader/loader.go

@@ -11,9 +11,9 @@ import (
 	"github.com/grafana/grafana/pkg/plugins/log"
 	"github.com/grafana/grafana/pkg/plugins/manager/loader/angular/angularinspector"
 	"github.com/grafana/grafana/pkg/plugins/manager/loader/assetpath"
-	"github.com/grafana/grafana/pkg/plugins/manager/loader/initializer"
 	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/bootstrap"
 	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/discovery"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/initialization"
 	"github.com/grafana/grafana/pkg/plugins/manager/process"
 	"github.com/grafana/grafana/pkg/plugins/manager/registry"
 	"github.com/grafana/grafana/pkg/plugins/manager/signature"
@@ -24,13 +24,13 @@ import (
 var _ plugins.ErrorResolver = (*Loader)(nil)
 
 type Loader struct {
-	discovery discovery.Discoverer
-	bootstrap bootstrap.Bootstrapper
+	discovery   discovery.Discoverer
+	bootstrap   bootstrap.Bootstrapper
+	initializer initialization.Initializer
 
 	processManager          process.Service
 	pluginRegistry          registry.Service
 	roleRegistry            plugins.RoleRegistry
-	pluginInitializer       initializer.Initializer
 	signatureValidator      signature.Validator
 	externalServiceRegistry oauth.ExternalServiceRegistry
 	assetPath               *assetpath.Service
@@ -42,23 +42,20 @@ type Loader struct {
 	errs map[string]*plugins.SignatureError
 }
 
-func ProvideService(cfg *config.Cfg, license plugins.Licensing, authorizer plugins.PluginLoaderAuthorizer,
-	pluginRegistry registry.Service, backendProvider plugins.BackendFactoryProvider,
-	roleRegistry plugins.RoleRegistry, assetPath *assetpath.Service,
+func ProvideService(cfg *config.Cfg, authorizer plugins.PluginLoaderAuthorizer,
+	pluginRegistry registry.Service, roleRegistry plugins.RoleRegistry, assetPath *assetpath.Service,
 	angularInspector angularinspector.Inspector, externalServiceRegistry oauth.ExternalServiceRegistry,
-	discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper) *Loader {
-	return New(cfg, license, authorizer, pluginRegistry, backendProvider, process.NewManager(pluginRegistry),
-		roleRegistry, assetPath, angularInspector, externalServiceRegistry, discovery, bootstrap)
+	discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper, initializer initialization.Initializer) *Loader {
+	return New(cfg, authorizer, pluginRegistry, process.NewManager(pluginRegistry), roleRegistry, assetPath,
+		angularInspector, externalServiceRegistry, discovery, bootstrap, initializer)
 }
 
-func New(cfg *config.Cfg, license plugins.Licensing, authorizer plugins.PluginLoaderAuthorizer,
-	pluginRegistry registry.Service, backendProvider plugins.BackendFactoryProvider,
+func New(cfg *config.Cfg, authorizer plugins.PluginLoaderAuthorizer, pluginRegistry registry.Service,
 	processManager process.Service, roleRegistry plugins.RoleRegistry, assetPath *assetpath.Service,
 	angularInspector angularinspector.Inspector, externalServiceRegistry oauth.ExternalServiceRegistry,
-	discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper) *Loader {
+	discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper, initializer initialization.Initializer) *Loader {
 	return &Loader{
 		pluginRegistry:          pluginRegistry,
-		pluginInitializer:       initializer.New(cfg, backendProvider, license),
 		signatureValidator:      signature.NewValidator(authorizer),
 		processManager:          processManager,
 		errs:                    make(map[string]*plugins.SignatureError),
@@ -70,6 +67,7 @@ func New(cfg *config.Cfg, license plugins.Licensing, authorizer plugins.PluginLo
 		externalServiceRegistry: externalServiceRegistry,
 		discovery:               discovery,
 		bootstrap:               bootstrap,
+		initializer:             initializer,
 	}
 }
 
@@ -144,24 +142,9 @@ func (l *Loader) Load(ctx context.Context, src plugins.PluginSource) ([]*plugins
 	// </VERIFICATION STAGE>
 
 	// <INITIALIZATION STAGE>
-	initializedPlugins := make([]*plugins.Plugin, 0, len(verifiedPlugins))
-	for _, p := range verifiedPlugins {
-		err = l.pluginInitializer.Initialize(ctx, p)
-		if err != nil {
-			l.log.Error("Could not initialize plugin", "pluginId", p.ID, "err", err)
-			continue
-		}
-
-		if err = l.pluginRegistry.Add(ctx, p); err != nil {
-			l.log.Error("Could not start plugin", "pluginId", p.ID, "err", err)
-			continue
-		}
-
-		if !p.IsCorePlugin() {
-			l.log.Info("Plugin registered", "pluginID", p.ID)
-		}
-
-		initializedPlugins = append(initializedPlugins, p)
+	initializedPlugins, err := l.initializer.Initialize(ctx, verifiedPlugins)
+	if err != nil {
+		return nil, err
 	}
 	// </INITIALIZATION STAGE>
 

pkg/plugins/manager/manager_integration_test.go

@@ -124,11 +124,11 @@ func TestIntegrationPluginManager(t *testing.T) {
 
 	discovery := pipeline.ProvideDiscoveryStage(pCfg, finder.NewLocalFinder(pCfg.DevMode), reg)
 	bootstrap := pipeline.ProvideBootstrapStage(pCfg, signature.ProvideService(pCfg, statickey.New()), assetpath.ProvideService(pluginscdn.ProvideService(pCfg)))
-
-	l := loader.ProvideService(pCfg, lic, signature.NewUnsignedAuthorizer(pCfg),
-		reg, provider.ProvideService(coreRegistry), fakes.NewFakeRoleRegistry(),
+	initialize := pipeline.ProvideInitializationStage(pCfg, reg, lic, provider.ProvideService(coreRegistry))
+	l := loader.ProvideService(pCfg, signature.NewUnsignedAuthorizer(pCfg),
+		reg, fakes.NewFakeRoleRegistry(),
 		assetpath.ProvideService(pluginscdn.ProvideService(pCfg)),
-		angularInspector, &fakes.FakeOauthService{}, discovery, bootstrap)
+		angularInspector, &fakes.FakeOauthService{}, discovery, bootstrap, initialize)
 	srcs := sources.ProvideService(cfg, pCfg)
 	ps, err := store.ProvideService(reg, srcs, l)
 	require.NoError(t, err)

pkg/plugins/manager/pipeline/bootstrap/bootstrap.go

@@ -47,7 +47,7 @@ func New(cfg *config.Cfg, opts Opts) *Bootstrap {
 		opts.ConstructFunc = DefaultConstructFunc(signature.DefaultCalculator(cfg), assetpath.DefaultService(cfg))
 	}
 
-	if len(opts.DecorateFuncs) == 0 {
+	if opts.DecorateFuncs == nil {
 		opts.DecorateFuncs = DefaultDecorateFuncs
 	}
 

pkg/plugins/manager/pipeline/discovery/discovery.go

@@ -45,7 +45,7 @@ func New(cfg *config.Cfg, opts Opts) *Discovery {
 		opts.FindFunc = DefaultFindFunc(cfg)
 	}
 
-	if len(opts.FindFilterFuncs) == 0 {
+	if opts.FindFilterFuncs == nil {
 		opts.FindFilterFuncs = []FindFilterFunc{} // no filters by default
 	}
 

pkg/plugins/manager/pipeline/initialization/doc.go

@@ -0,0 +1,6 @@
+// Package initialization defines the fourth stage of the plugin loader pipeline.
+//
+// The Initialization stage must implement the Initializer interface.
+// - Initialize(ctx context.Context, ps []*plugins.Plugin) ([]*plugins.Plugin, error)
+
+package initialization

pkg/plugins/manager/pipeline/initialization/initialization.go

@@ -0,0 +1,67 @@
+package initialization
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/config"
+	"github.com/grafana/grafana/pkg/plugins/log"
+)
+
+// Initializer is responsible for the Initialization stage of the plugin loader pipeline.
+type Initializer interface {
+	Initialize(ctx context.Context, ps []*plugins.Plugin) ([]*plugins.Plugin, error)
+}
+
+// InitializeFunc is the function used for the Initialize step of the Initialization stage.
+type InitializeFunc func(ctx context.Context, p *plugins.Plugin) (*plugins.Plugin, error)
+
+type Initialize struct {
+	cfg             *config.Cfg
+	initializeSteps []InitializeFunc
+	log             log.Logger
+}
+
+type Opts struct {
+	InitializeFuncs []InitializeFunc
+}
+
+// New returns a new Initialization stage.
+func New(cfg *config.Cfg, opts Opts) *Initialize {
+	if opts.InitializeFuncs == nil {
+		opts.InitializeFuncs = []InitializeFunc{}
+	}
+
+	return &Initialize{
+		cfg:             cfg,
+		initializeSteps: opts.InitializeFuncs,
+		log:             log.New("plugins.initialization"),
+	}
+}
+
+// Initialize will execute the Initialize steps of the Initialization stage.
+func (i *Initialize) Initialize(ctx context.Context, ps []*plugins.Plugin) ([]*plugins.Plugin, error) {
+	if len(i.initializeSteps) == 0 {
+		return ps, nil
+	}
+
+	var err error
+	initializedPlugins := make([]*plugins.Plugin, 0, len(ps))
+	for _, p := range ps {
+		var ip *plugins.Plugin
+		stepFailed := false
+		for _, init := range i.initializeSteps {
+			ip, err = init(ctx, p)
+			if err != nil {
+				stepFailed = true
+				i.log.Error("Could not initialize plugin", "pluginId", p.ID, "err", err)
+				break
+			}
+		}
+		if !stepFailed {
+			initializedPlugins = append(initializedPlugins, ip)
+		}
+	}
+
+	return initializedPlugins, nil
+}

pkg/plugins/manager/pipeline/initialization/steps.go

@@ -0,0 +1,90 @@
+package initialization
+
+import (
+	"context"
+	"errors"
+
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/envvars"
+	"github.com/grafana/grafana/pkg/plugins/log"
+	"github.com/grafana/grafana/pkg/plugins/manager/registry"
+)
+
+// BackendClientInit implements an InitializeFunc for initializing a backend plugin process.
+//
+// It uses the envvars.Provider to retrieve the environment variables required for the plugin and the plugins.BackendFactoryProvider
+// to get fetch backend factory, which is used to form a connection to the backend plugin process.
+//
+// Note: This step does not start the backend plugin process.
+type BackendClientInit struct {
+	envVarProvider  envvars.Provider
+	backendProvider plugins.BackendFactoryProvider
+	log             log.Logger
+}
+
+// NewBackendClientInitStep returns a new InitializeFunc for registering a backend plugin process.
+func NewBackendClientInitStep(envVarProvider envvars.Provider,
+	backendProvider plugins.BackendFactoryProvider) InitializeFunc {
+	return newBackendProcessRegistration(envVarProvider, backendProvider).Initialize
+}
+
+func newBackendProcessRegistration(envVarProvider envvars.Provider,
+	backendProvider plugins.BackendFactoryProvider) *BackendClientInit {
+	return &BackendClientInit{
+		backendProvider: backendProvider,
+		envVarProvider:  envVarProvider,
+		log:             log.New("plugins.backend.registration"),
+	}
+}
+
+// Initialize will initialize a backend plugin client, if the plugin is a backend plugin.
+func (b *BackendClientInit) Initialize(ctx context.Context, p *plugins.Plugin) (*plugins.Plugin, error) {
+	if p.Backend {
+		backendFactory := b.backendProvider.BackendFactory(ctx, p)
+		if backendFactory == nil {
+			return nil, errors.New("could not find backend factory for plugin")
+		}
+
+		env, err := b.envVarProvider.Get(ctx, p)
+		if err != nil {
+			return nil, err
+		}
+		if backendClient, err := backendFactory(p.ID, p.Logger(), env); err != nil {
+			return nil, err
+		} else {
+			p.RegisterClient(backendClient)
+		}
+	}
+	return p, nil
+}
+
+// PluginRegistration implements an InitializeFunc for registering a plugin with the plugin registry.
+type PluginRegistration struct {
+	pluginRegistry registry.Service
+	log            log.Logger
+}
+
+// NewPluginRegistrationStep returns a new InitializeFunc for registering a plugin with the plugin registry.
+func NewPluginRegistrationStep(pluginRegistry registry.Service) InitializeFunc {
+	return newPluginRegistration(pluginRegistry).Initialize
+}
+
+func newPluginRegistration(pluginRegistry registry.Service) *PluginRegistration {
+	return &PluginRegistration{
+		pluginRegistry: pluginRegistry,
+		log:            log.New("plugins.registration"),
+	}
+}
+
+// Initialize registers the plugin with the plugin registry.
+func (r *PluginRegistration) Initialize(ctx context.Context, p *plugins.Plugin) (*plugins.Plugin, error) {
+	if err := r.pluginRegistry.Add(ctx, p); err != nil {
+		r.log.Error("Could not register plugin", "pluginID", p.ID, "err", err)
+		return nil, errors.New("could not register plugin")
+	}
+	if !p.IsCorePlugin() {
+		r.log.Info("Plugin registered", "pluginID", p.ID)
+	}
+
+	return p, nil
+}

pkg/plugins/manager/pipeline/initialization/steps_test.go

@@ -1,10 +1,10 @@
-package initializer
+package initialization
 
 import (
 	"context"
 	"testing"
 
-	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/plugins/backendplugin"
@@ -28,19 +28,15 @@ func TestInitializer_Initialize(t *testing.T) {
 			Class: plugins.ClassCore,
 		}
 
-		i := &Initializer{
-			backendProvider: &fakeBackendProvider{
-				plugin: p,
-			},
-			envVarProvider: &fakeEnvVarsProvider{},
-		}
+		stepFunc := NewBackendClientInitStep(&fakeEnvVarsProvider{}, &fakeBackendProvider{plugin: p})
 
-		err := i.Initialize(context.Background(), p)
-		assert.NoError(t, err)
+		var err error
+		p, err = stepFunc(context.Background(), p)
+		require.NoError(t, err)
 
 		c, exists := p.Client()
-		assert.True(t, exists)
-		assert.NotNil(t, c)
+		require.True(t, exists)
+		require.NotNil(t, c)
 	})
 
 	t.Run("renderer", func(t *testing.T) {
@@ -56,19 +52,15 @@ func TestInitializer_Initialize(t *testing.T) {
 			Class: plugins.ClassExternal,
 		}
 
-		i := &Initializer{
-			backendProvider: &fakeBackendProvider{
-				plugin: p,
-			},
-			envVarProvider: &fakeEnvVarsProvider{},
-		}
+		stepFunc := NewBackendClientInitStep(&fakeEnvVarsProvider{}, &fakeBackendProvider{plugin: p})
 
-		err := i.Initialize(context.Background(), p)
-		assert.NoError(t, err)
+		var err error
+		p, err = stepFunc(context.Background(), p)
+		require.NoError(t, err)
 
 		c, exists := p.Client()
-		assert.True(t, exists)
-		assert.NotNil(t, c)
+		require.True(t, exists)
+		require.NotNil(t, c)
 	})
 
 	t.Run("secretsmanager", func(t *testing.T) {
@@ -84,19 +76,15 @@ func TestInitializer_Initialize(t *testing.T) {
 			Class: plugins.ClassExternal,
 		}
 
-		i := &Initializer{
-			backendProvider: &fakeBackendProvider{
-				plugin: p,
-			},
-			envVarProvider: &fakeEnvVarsProvider{},
-		}
+		stepFunc := NewBackendClientInitStep(&fakeEnvVarsProvider{}, &fakeBackendProvider{plugin: p})
 
-		err := i.Initialize(context.Background(), p)
-		assert.NoError(t, err)
+		var err error
+		p, err = stepFunc(context.Background(), p)
+		require.NoError(t, err)
 
 		c, exists := p.Client()
-		assert.True(t, exists)
-		assert.NotNil(t, c)
+		require.True(t, exists)
+		require.NotNil(t, c)
 	})
 
 	t.Run("non backend plugin app", func(t *testing.T) {
@@ -106,19 +94,17 @@ func TestInitializer_Initialize(t *testing.T) {
 			},
 		}
 
-		i := &Initializer{
-			backendProvider: &fakeBackendProvider{
-				plugin: p,
-			},
-			envVarProvider: &fakeEnvVarsProvider{},
-		}
+		i := NewBackendClientInitStep(&fakeEnvVarsProvider{}, &fakeBackendProvider{
+			plugin: p,
+		})
 
-		err := i.Initialize(context.Background(), p)
-		assert.NoError(t, err)
+		var err error
+		p, err = i(context.Background(), p)
+		require.NoError(t, err)
 
 		c, exists := p.Client()
-		assert.False(t, exists)
-		assert.Nil(t, c)
+		require.False(t, exists)
+		require.Nil(t, c)
 	})
 }
 

pkg/services/pluginsintegration/loader/loader.go

@@ -0,0 +1,47 @@
+package loader
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/config"
+	pluginsLoader "github.com/grafana/grafana/pkg/plugins/manager/loader"
+	"github.com/grafana/grafana/pkg/plugins/manager/loader/angular/angularinspector"
+	"github.com/grafana/grafana/pkg/plugins/manager/loader/assetpath"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/bootstrap"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/discovery"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/initialization"
+	"github.com/grafana/grafana/pkg/plugins/manager/process"
+	"github.com/grafana/grafana/pkg/plugins/manager/registry"
+	"github.com/grafana/grafana/pkg/plugins/oauth"
+)
+
+var _ plugins.ErrorResolver = (*Loader)(nil)
+var _ pluginsLoader.Service = (*Loader)(nil)
+
+type Loader struct {
+	loader *pluginsLoader.Loader
+}
+
+func ProvideService(cfg *config.Cfg, authorizer plugins.PluginLoaderAuthorizer, processManager process.Service,
+	pluginRegistry registry.Service, roleRegistry plugins.RoleRegistry, assetPath *assetpath.Service,
+	angularInspector angularinspector.Inspector, externalServiceRegistry oauth.ExternalServiceRegistry,
+	discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper, initializer initialization.Initializer,
+) *Loader {
+	return &Loader{
+		loader: pluginsLoader.New(cfg, authorizer, pluginRegistry, processManager, roleRegistry, assetPath,
+			angularInspector, externalServiceRegistry, discovery, bootstrap, initializer),
+	}
+}
+
+func (l *Loader) Load(ctx context.Context, src plugins.PluginSource) ([]*plugins.Plugin, error) {
+	return l.loader.Load(ctx, src)
+}
+
+func (l *Loader) Unload(ctx context.Context, pluginID string) error {
+	return l.loader.Unload(ctx, pluginID)
+}
+
+func (l *Loader) PluginErrors() []*plugins.Error {
+	return l.loader.PluginErrors()
+}

pkg/services/pluginsintegration/pipeline/discovery.go

@@ -1,33 +0,0 @@
-package pipeline
-
-import (
-	"context"
-
-	"github.com/grafana/grafana/pkg/plugins"
-	"github.com/grafana/grafana/pkg/plugins/config"
-	"github.com/grafana/grafana/pkg/plugins/manager/loader/assetpath"
-	"github.com/grafana/grafana/pkg/plugins/manager/loader/finder"
-	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/bootstrap"
-	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/discovery"
-	"github.com/grafana/grafana/pkg/plugins/manager/registry"
-)
-
-func ProvideDiscoveryStage(cfg *config.Cfg, pluginFinder finder.Finder, pluginRegistry registry.Service) *discovery.Discovery {
-	return discovery.New(cfg, discovery.Opts{
-		FindFunc: func(ctx context.Context, src plugins.PluginSource) ([]*plugins.FoundBundle, error) {
-			return pluginFinder.Find(ctx, src)
-		},
-		FindFilterFuncs: []discovery.FindFilterFunc{
-			func(ctx context.Context, _ plugins.Class, bundles []*plugins.FoundBundle) ([]*plugins.FoundBundle, error) {
-				return discovery.NewDuplicatePluginFilterStep(pluginRegistry).Filter(ctx, bundles)
-			},
-		},
-	})
-}
-
-func ProvideBootstrapStage(cfg *config.Cfg, signatureCalculator plugins.SignatureCalculator, assetPath *assetpath.Service) *bootstrap.Bootstrap {
-	return bootstrap.New(cfg, bootstrap.Opts{
-		ConstructFunc: bootstrap.DefaultConstructFunc(signatureCalculator, assetPath),
-		DecorateFuncs: bootstrap.DefaultDecorateFuncs,
-	})
-}

pkg/services/pluginsintegration/pipeline/pipeline.go

@@ -0,0 +1,44 @@
+package pipeline
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/config"
+	"github.com/grafana/grafana/pkg/plugins/envvars"
+	"github.com/grafana/grafana/pkg/plugins/manager/loader/assetpath"
+	"github.com/grafana/grafana/pkg/plugins/manager/loader/finder"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/bootstrap"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/discovery"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/initialization"
+	"github.com/grafana/grafana/pkg/plugins/manager/registry"
+)
+
+func ProvideDiscoveryStage(cfg *config.Cfg, pf finder.Finder, pr registry.Service) *discovery.Discovery {
+	return discovery.New(cfg, discovery.Opts{
+		FindFunc: func(ctx context.Context, src plugins.PluginSource) ([]*plugins.FoundBundle, error) {
+			return pf.Find(ctx, src)
+		},
+		FindFilterFuncs: []discovery.FindFilterFunc{
+			func(ctx context.Context, _ plugins.Class, b []*plugins.FoundBundle) ([]*plugins.FoundBundle, error) {
+				return discovery.NewDuplicatePluginFilterStep(pr).Filter(ctx, b)
+			},
+		},
+	})
+}
+
+func ProvideBootstrapStage(cfg *config.Cfg, sc plugins.SignatureCalculator, a *assetpath.Service) *bootstrap.Bootstrap {
+	return bootstrap.New(cfg, bootstrap.Opts{
+		ConstructFunc: bootstrap.DefaultConstructFunc(sc, a),
+		DecorateFuncs: bootstrap.DefaultDecorateFuncs,
+	})
+}
+
+func ProvideInitializationStage(cfg *config.Cfg, pr registry.Service, l plugins.Licensing, bp plugins.BackendFactoryProvider) *initialization.Initialize {
+	return initialization.New(cfg, initialization.Opts{
+		InitializeFuncs: []initialization.InitializeFunc{
+			initialization.NewBackendClientInitStep(envvars.NewProvider(cfg, l), bp),
+			initialization.NewPluginRegistrationStep(pr),
+		},
+	})
+}

pkg/services/pluginsintegration/pluginsintegration.go

@@ -11,12 +11,13 @@ import (
 	"github.com/grafana/grafana/pkg/plugins/manager"
 	"github.com/grafana/grafana/pkg/plugins/manager/client"
 	"github.com/grafana/grafana/pkg/plugins/manager/filestore"
-	"github.com/grafana/grafana/pkg/plugins/manager/loader"
+	pluginLoader "github.com/grafana/grafana/pkg/plugins/manager/loader"
 	pAngularInspector "github.com/grafana/grafana/pkg/plugins/manager/loader/angular/angularinspector"
 	"github.com/grafana/grafana/pkg/plugins/manager/loader/assetpath"
 	"github.com/grafana/grafana/pkg/plugins/manager/loader/finder"
 	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/bootstrap"
 	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/discovery"
+	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/initialization"
 	"github.com/grafana/grafana/pkg/plugins/manager/process"
 	"github.com/grafana/grafana/pkg/plugins/manager/registry"
 	"github.com/grafana/grafana/pkg/plugins/manager/signature"
@@ -37,6 +38,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/keyretriever/dynamic"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/keystore"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/licensing"
+	"github.com/grafana/grafana/pkg/services/pluginsintegration/loader"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/pipeline"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/plugincontext"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/pluginsettings"
@@ -65,6 +67,8 @@ var WireSet = wire.NewSet(
 	wire.Bind(new(discovery.Discoverer), new(*discovery.Discovery)),
 	pipeline.ProvideBootstrapStage,
 	wire.Bind(new(bootstrap.Bootstrapper), new(*bootstrap.Bootstrap)),
+	pipeline.ProvideInitializationStage,
+	wire.Bind(new(initialization.Initializer), new(*initialization.Initialize)),
 
 	angularpatternsstore.ProvideService,
 	angulardetectorsprovider.ProvideDynamic,
@@ -72,7 +76,7 @@ var WireSet = wire.NewSet(
 	wire.Bind(new(pAngularInspector.Inspector), new(*angularinspector.Service)),
 
 	loader.ProvideService,
-	wire.Bind(new(loader.Service), new(*loader.Loader)),
+	wire.Bind(new(pluginLoader.Service), new(*loader.Loader)),
 	wire.Bind(new(plugins.ErrorResolver), new(*loader.Loader)),
 	manager.ProvideInstaller,
 	wire.Bind(new(plugins.Installer), new(*manager.PluginInstaller)),