Backend Plugins: Plugin configuration using Grafana config (#23451)

Enables adding a section `plugin.<plugin id>` and key/value to
Grafana configuration file which will be converted and sent
as environment variables to the backend plugin.
Also sends some additional environment variables, Grafana
version (GF_VERSION), Grafana edition (GF_EDITION) and 
enterprise license path (GF_ENTERPRISE_LICENSE_PATH).

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

Fixes #21515,

pkg/plugins/backendplugin/client.go

@@ -30,9 +30,12 @@ var handshake = goplugin.HandshakeConfig{
 	MagicCookieValue: grpcplugin.MagicCookieValue,
 }
 
-func newClientConfig(executablePath string, logger log.Logger, versionedPlugins map[int]goplugin.PluginSet) *goplugin.ClientConfig {
+func newClientConfig(executablePath string, env []string, logger log.Logger, versionedPlugins map[int]goplugin.PluginSet) *goplugin.ClientConfig {
+	cmd := exec.Command(executablePath)
+	cmd.Env = env
+
 	return &goplugin.ClientConfig{
-		Cmd:              exec.Command(executablePath),
+		Cmd:              cmd,
 		HandshakeConfig:  handshake,
 		VersionedPlugins: versionedPlugins,
 		Logger:           logWrapper{Logger: logger},

pkg/plugins/backendplugin/manager.go

@@ -3,11 +3,13 @@ package backendplugin
 import (
 	"context"
 	"errors"
+	"fmt"
 	"io"
 	"sync"
 	"time"
 
 	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util/errutil"
 	"github.com/grafana/grafana/pkg/util/proxyutil"
 
@@ -49,14 +51,18 @@ type Manager interface {
 }
 
 type manager struct {
+	Cfg            *setting.Cfg     `inject:""`
+	License        models.Licensing `inject:""`
 	pluginsMu      sync.RWMutex
 	plugins        map[string]*BackendPlugin
 	logger         log.Logger
+	pluginSettings map[string]pluginSettings
 }
 
 func (m *manager) Init() error {
 	m.plugins = make(map[string]*BackendPlugin)
 	m.logger = log.New("plugins.backend")
+	m.pluginSettings = extractPluginSettings(m.Cfg)
 
 	return nil
 }
@@ -78,13 +84,29 @@ func (m *manager) Register(descriptor PluginDescriptor) error {
 		return errors.New("Backend plugin already registered")
 	}
 
+	pluginSettings := pluginSettings{}
+	if ps, exists := m.pluginSettings[descriptor.pluginID]; exists {
+		pluginSettings = ps
+	}
+
+	hostEnv := []string{
+		fmt.Sprintf("GF_VERSION=%s", setting.BuildVersion),
+		fmt.Sprintf("GF_EDITION=%s", m.License.Edition()),
+	}
+
+	if m.License.HasLicense() {
+		hostEnv = append(hostEnv, fmt.Sprintf("GF_ENTERPRISE_LICENSE_PATH=%s", m.Cfg.EnterpriseLicensePath))
+	}
+
+	env := pluginSettings.ToEnv("GF_PLUGIN", hostEnv)
+
 	pluginLogger := m.logger.New("pluginId", descriptor.pluginID)
 	plugin := &BackendPlugin{
 		id:             descriptor.pluginID,
 		executablePath: descriptor.executablePath,
 		managed:        descriptor.managed,
 		clientFactory: func() *plugin.Client {
-			return plugin.NewClient(newClientConfig(descriptor.executablePath, pluginLogger, descriptor.versionedPlugins))
+			return plugin.NewClient(newClientConfig(descriptor.executablePath, env, pluginLogger, descriptor.versionedPlugins))
 		},
 		startFns: descriptor.startFns,
 		logger:   pluginLogger,

pkg/plugins/backendplugin/plugin_settings.go

@@ -0,0 +1,39 @@
+package backendplugin
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+type pluginSettings map[string]string
+
+func (ps pluginSettings) ToEnv(prefix string, hostEnv []string) []string {
+	env := []string{}
+	for k, v := range ps {
+		env = append(env, fmt.Sprintf("%s_%s=%s", prefix, strings.ToUpper(k), v))
+	}
+
+	env = append(env, hostEnv...)
+
+	return env
+}
+
+func extractPluginSettings(cfg *setting.Cfg) map[string]pluginSettings {
+	psMap := map[string]pluginSettings{}
+	for pluginID, settings := range cfg.PluginSettings {
+		ps := pluginSettings{}
+		for k, v := range settings {
+			if k == "path" || strings.ToLower(k) == "id" {
+				continue
+			}
+
+			ps[k] = v
+		}
+
+		psMap[pluginID] = ps
+	}
+
+	return psMap
+}

pkg/plugins/backendplugin/plugin_settings_test.go

@@ -0,0 +1,46 @@
+package backendplugin
+
+import (
+	"sort"
+	"testing"
+
+	"github.com/grafana/grafana/pkg/setting"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPluginSettings(t *testing.T) {
+	t.Run("Should only extract from sections beginning with 'plugin.' in config", func(t *testing.T) {
+		cfg := &setting.Cfg{
+			PluginSettings: setting.PluginSettings{
+				"plugin": map[string]string{
+					"key1": "value1",
+					"key2": "value2",
+				},
+			},
+		}
+
+		ps := extractPluginSettings(cfg)
+		require.Len(t, ps, 1)
+		require.Len(t, ps["plugin"], 2)
+
+		t.Run("Should skip path setting", func(t *testing.T) {
+			cfg.PluginSettings["plugin"]["path"] = "value"
+			ps := extractPluginSettings(cfg)
+			require.Len(t, ps["plugin"], 2)
+		})
+
+		t.Run("Should skip id setting", func(t *testing.T) {
+			cfg.PluginSettings["plugin"]["id"] = "value"
+			ps := extractPluginSettings(cfg)
+			require.Len(t, ps["plugin"], 2)
+		})
+
+		t.Run("Should return expected environment variables from plugin settings ", func(t *testing.T) {
+			ps := extractPluginSettings(cfg)
+			env := ps["plugin"].ToEnv("GF_PLUGIN", []string{"GF_VERSION=6.7.0"})
+			sort.Strings(env)
+			require.Len(t, env, 3)
+			require.EqualValues(t, []string{"GF_PLUGIN_KEY1=value1", "GF_PLUGIN_KEY2=value2", "GF_VERSION=6.7.0"}, env)
+		})
+	})
+}

pkg/plugins/dashboard_importer_test.go

@@ -9,7 +9,6 @@ import (
 	"github.com/grafana/grafana/pkg/services/dashboards"
 	"github.com/grafana/grafana/pkg/setting"
 	. "github.com/smartystreets/goconvey/convey"
-	"gopkg.in/ini.v1"
 )
 
 func TestDashboardImport(t *testing.T) {
@@ -87,17 +86,17 @@ func TestDashboardImport(t *testing.T) {
 
 func pluginScenario(desc string, t *testing.T, fn func()) {
 	Convey("Given a plugin", t, func() {
-		setting.Raw = ini.Empty()
-		sec, _ := setting.Raw.NewSection("plugin.test-app")
-		_, err := sec.NewKey("path", "testdata/test-app")
-		So(err, ShouldBeNil)
-
 		pm := &PluginManager{
 			Cfg: &setting.Cfg{
 				FeatureToggles: map[string]bool{},
+				PluginSettings: setting.PluginSettings{
+					"test-app": map[string]string{
+						"path": "testdata/test-app",
+					},
+				},
 			},
 		}
-		err = pm.Init()
+		err := pm.Init()
 		So(err, ShouldBeNil)
 
 		Convey(desc, fn)

pkg/plugins/dashboards_test.go

@@ -8,22 +8,21 @@ import (
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/setting"
 	. "github.com/smartystreets/goconvey/convey"
-	"gopkg.in/ini.v1"
 )
 
 func TestPluginDashboards(t *testing.T) {
 	Convey("When asking plugin dashboard info", t, func() {
-		setting.Raw = ini.Empty()
-		sec, _ := setting.Raw.NewSection("plugin.test-app")
-		_, err := sec.NewKey("path", "testdata/test-app")
-		So(err, ShouldBeNil)
-
 		pm := &PluginManager{
 			Cfg: &setting.Cfg{
 				FeatureToggles: map[string]bool{},
+				PluginSettings: setting.PluginSettings{
+					"test-app": map[string]string{
+						"path": "testdata/test-app",
+					},
+				},
 			},
 		}
-		err = pm.Init()
+		err := pm.Init()
 		So(err, ShouldBeNil)
 
 		bus.AddHandler("test", func(query *models.GetDashboardQuery) error {

pkg/plugins/plugins.go

@@ -153,19 +153,14 @@ func (pm *PluginManager) Run(ctx context.Context) error {
 }
 
 func (pm *PluginManager) checkPluginPaths() error {
-	for _, section := range setting.Raw.Sections() {
-		if !strings.HasPrefix(section.Name(), "plugin.") {
-			continue
-		}
-
-		path := section.Key("path").String()
-		if path == "" {
+	for pluginID, settings := range pm.Cfg.PluginSettings {
+		path, exists := settings["path"]
+		if !exists || path == "" {
 			continue
 		}
 
 		if err := pm.scan(path); err != nil {
-			return errutil.Wrapf(err, "Failed to scan directory configured for plugin '%s': '%s'",
-				section.Name(), path)
+			return errutil.Wrapf(err, "Failed to scan directory configured for plugin '%s': '%s'", pluginID, path)
 		}
 	}
 

pkg/plugins/plugins_test.go

@@ -32,18 +32,17 @@ func TestPluginScans(t *testing.T) {
 	})
 
 	Convey("When reading app plugin definition", t, func() {
-		setting.Raw = ini.Empty()
-		sec, err := setting.Raw.NewSection("plugin.nginx-app")
-		So(err, ShouldBeNil)
-		_, err = sec.NewKey("path", "testdata/test-app")
-		So(err, ShouldBeNil)
-
 		pm := &PluginManager{
 			Cfg: &setting.Cfg{
 				FeatureToggles: map[string]bool{},
+				PluginSettings: setting.PluginSettings{
+					"nginx-app": map[string]string{
+						"path": "testdata/test-app",
+					},
+				},
 			},
 		}
-		err = pm.Init()
+		err := pm.Init()
 		So(err, ShouldBeNil)
 
 		So(len(Apps), ShouldBeGreaterThan, 0)

pkg/setting/setting.go

@@ -259,6 +259,7 @@ type Cfg struct {
 	MetricsEndpointDisableTotalStats bool
 	PluginsEnableAlpha               bool
 	PluginsAppsSkipVerifyTLS         bool
+	PluginSettings                   PluginSettings
 	DisableSanitizeHtml              bool
 	EnterpriseLicensePath            string
 

pkg/setting/setting_plugins.go

@@ -0,0 +1,25 @@
+package setting
+
+import (
+	"strings"
+
+	"gopkg.in/ini.v1"
+)
+
+// PluginSettings maps plugin id to map of key/value settings.
+type PluginSettings map[string]map[string]string
+
+func extractPluginSettings(sections []*ini.Section) PluginSettings {
+	psMap := PluginSettings{}
+	for _, section := range sections {
+		sectionName := section.Name()
+		if !strings.HasPrefix(sectionName, "plugin.") {
+			continue
+		}
+
+		pluginID := strings.Replace(sectionName, "plugin.", "", 1)
+		psMap[pluginID] = section.KeysHash()
+	}
+
+	return psMap
+}

pkg/setting/setting_plugins_test.go

@@ -0,0 +1,43 @@
+package setting
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPluginSettings(t *testing.T) {
+	cfg := NewCfg()
+	sec, err := cfg.Raw.NewSection("plugin")
+	require.NoError(t, err)
+	_, err = sec.NewKey("key", "value")
+	require.NoError(t, err)
+
+	sec, err = cfg.Raw.NewSection("plugin.plugin")
+	require.NoError(t, err)
+	_, err = sec.NewKey("key1", "value1")
+	require.NoError(t, err)
+	_, err = sec.NewKey("key2", "value2")
+	require.NoError(t, err)
+
+	sec, err = cfg.Raw.NewSection("plugin.plugin2")
+	require.NoError(t, err)
+	_, err = sec.NewKey("key3", "value3")
+	require.NoError(t, err)
+	_, err = sec.NewKey("key4", "value4")
+	require.NoError(t, err)
+
+	sec, err = cfg.Raw.NewSection("other")
+	require.NoError(t, err)
+	_, err = sec.NewKey("keySomething", "whatever")
+	require.NoError(t, err)
+
+	ps := extractPluginSettings(cfg.Raw.Sections())
+	require.Len(t, ps, 2)
+	require.Len(t, ps["plugin"], 2)
+	require.Equal(t, ps["plugin"]["key1"], "value1")
+	require.Equal(t, ps["plugin"]["key2"], "value2")
+	require.Len(t, ps["plugin2"], 2)
+	require.Equal(t, ps["plugin2"]["key3"], "value3")
+	require.Equal(t, ps["plugin2"]["key4"], "value4")
+}